nginx-contoh.conf

# Generated by nginxconfig.io
# See nginxconfig.txt for the configuration share link
# Note in comments by Harisfazillah Jamel and Google Gemini
# 15 Jun 2025

user                 www-data;
pid                  /run/nginx.pid;
worker_processes     auto;
worker_rlimit_nofile 65535;

# Load modules
include              /etc/nginx/modules-enabled/*.conf;

events {
    multi_accept       on;
    worker_connections 65535;
}

http {
    charset                utf-8;
    sendfile               on;
    tcp_nopush             on;
    tcp_nodelay            on;
    server_tokens          off;
    types_hash_max_size    2048;
    types_hash_bucket_size 64;
    client_max_body_size   16M;

    # MIME
    include                mime.types;
    default_type           application/octet-stream;
    
    # Log Format
    log_format             cloudflare '$remote_addr - $remote_user [$time_local] "$request" $status $body_bytes_sent "$http_referer" "$http_user_agent" $http_cf_ray $http_cf_connecting_ip $http_x_forwarded_for $http_x_forwarded_proto $http_true_client_ip $http_cf_ipcountry $http_cf_visitor $http_cdn_loop';

    # Logging
    access_log             off;
    error_log              /var/log/nginx/error.log warn;

    # Limits
    limit_req_log_level    warn;
    limit_req_zone         $binary_remote_addr zone=login:10m rate=10r/m;

    # SSL
    ssl_session_timeout    1d;
    ssl_session_cache      shared:SSL:10m;
    ssl_session_tickets    off;

    # Mozilla Modern configuration
    ssl_protocols          TLSv1.3;

    # OCSP Stapling
    ssl_stapling           on;
    ssl_stapling_verify    on;
    resolver               1.1.1.1 1.0.0.1 [2606:4700:4700::1111] [2606:4700:4700::1001] 8.8.8.8 8.8.4.4 [2001:4860:4860::8888] [2001:4860:4860::8844] 208.67.222.222 208.67.220.220 [2620:119:35::35] [2620:119:53::53] 9.9.9.9 149.112.112.112 [2620:fe::fe] [2620:fe::9] 64.6.64.6 64.6.65.6 [2620:74:1b::1:1] [2620:74:1c::2:2] valid=60s;
    resolver_timeout       2s;

    # Connection header for WebSocket reverse proxy
    map $http_upgrade $connection_upgrade {
        default upgrade;
        ""      close;
    }

    map $remote_addr $proxy_forwarded_elem {

        # IPv4 addresses can be sent as-is
        ~^[0-9.]+$        "for=$remote_addr";

        # IPv6 addresses need to be bracketed and quoted
        ~^[0-9A-Fa-f:.]+$ "for=\"[$remote_addr]\"";

        # Unix domain socket names cannot be represented in RFC 7239 syntax
        default           "for=unknown";
    }

    map $http_forwarded $proxy_add_forwarded {

        # If the incoming Forwarded header is syntactically valid, append to it
        "~^(,[ \\t]*)*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*([ \\t]*,([ \\t]*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*)?)*$" "$http_forwarded, $proxy_forwarded_elem";

        # Otherwise, replace it
        default "$proxy_forwarded_elem";
    }

    # --- NGINX CACHE CONFIGURATION START ---
    # Define a cache zone named 'my_cache'
    # Keys will be stored in memory (10m)
    # Total cache size will be 1g
    # Inactive items will be removed after 60m
    # Cache directory: /var/cache/nginx
    proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;
    # --- NGINX CACHE CONFIGURATION END ---

    # Load configs
    include /etc/nginx/conf.d/*.conf;

    # linuxmalaysia.com
    
    server {
        listen                               443 ssl reuseport;
        listen                               [::]:443 ssl reuseport;
        http2 on;
        server_name                          linuxmalaysia.com;
        root                                 /var/www/linuxmalaysia.com/public;

        # SSL
        ssl_certificate                      /etc/nginx/ssl/linuxmalaysia.com.crt;
        ssl_certificate_key                  /etc/nginx/ssl/linuxmalaysia.com.key;

        # security headers
        add_header X-XSS-Protection          "1; mode=block" always;
        add_header X-Content-Type-Options    "nosniff" always;
        add_header Referrer-Policy           "no-referrer-when-downgrade" always;
        add_header Content-Security-Policy   "default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline'; frame-ancestors 'self';" always;
        add_header Permissions-Policy        "interest-cohort=()" always;
        add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

        # . files
        location ~ /\.(?!well-known) {
            deny all;
        }

        # security.txt
        location /security.txt {
            return 301 /.well-known/security.txt;
        }

        location = /.well-known/security.txt {
            alias ~/security.txt;
        }

        # restrict methods
        if ($request_method !~ ^(GET|POST|PUT|HEAD|CONNECT)$) {
            return '405';
        }

        # logging
        access_log /var/log/nginx/access.log combined buffer=512k flush=1m;
        error_log  /var/log/nginx/error.log warn;

        # reverse proxy
        location / {
            proxy_pass                         http://127.0.0.1:3000;
            proxy_set_header Host              $host;
            proxy_http_version                 1.1;
            proxy_cache_bypass                 $http_upgrade;

            # --- NGINX CACHE APPLICATION START ---
            proxy_cache my_cache; # Use the defined cache zone
            proxy_cache_valid 200 302 10m; # Cache successful responses for 10 minutes
            proxy_cache_valid 404 1m;      # Cache 404 responses for 1 minute
            proxy_cache_key "$scheme$proxy_host$request_uri"; # Define the cache key
            proxy_cache_min_uses 1; # Cache after 1 request
            proxy_cache_revalidate on; # Revalidate stale content
            proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504; # Serve stale content on errors
            # Add header to see if content is served from cache (optional, for debugging)
            add_header X-Cache-Status $upstream_cache_status;
            # --- NGINX CACHE APPLICATION END ---

            # Proxy SSL
            proxy_ssl_server_name              on;

            # Proxy headers
            proxy_set_header Upgrade           $http_upgrade;
            proxy_set_header Connection        $connection_upgrade;
            proxy_set_header X-Real-IP         $remote_addr;
            proxy_set_header Forwarded         $proxy_add_forwarded;
            proxy_set_header X-Forwarded-For   $proxy_add_x_forwarded_for;
            proxy_set_header X-Forwarded-Proto $scheme;
            proxy_set_header X-Forwarded-Host  $host;
            proxy_set_header X-Forwarded-Port  $server_port;

            # Proxy timeouts
            proxy_connect_timeout              60s;
            proxy_send_timeout                 60s;
            proxy_read_timeout                 60s;
        }

        # favicon.ico
        location = /favicon.ico {
            log_not_found off;
        }

        # robots.txt
        location = /robots.txt {
            log_not_found off;
        }

#        # assets, media
#        location ~* \.(?:css(\.map)?|js(\.map)?|jpe?g|png|gif|ico|cur|heic|webp|tiff?|mp3|m4a|aac|ogg|midi?|wav|mp4|mov|webm|mpe?g|avi|ogv|flv|wmv)$ {
#            expires 7d;
#        }
#
#        # svg, fonts
#        location ~* \.(?:svgz?|ttf|ttc|otf|eot|woff2?)$ {
#            add_header Access-Control-Allow-Origin "*";
#            expires    7d;
#        }

        # gzip
        gzip            on;
        gzip_vary       on;
        gzip_proxied    any;
        gzip_comp_level 6;
        gzip_types      text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml;
    }

    # HTTP redirect
    server {
        listen      80 reuseport;
        listen      [::]:80 reuseport;
        server_name linuxmalaysia.com;

        # logging
        access_log  /var/log/nginx/access.log combined buffer=512k flush=1m;
        error_log   /var/log/nginx/error.log warn;
        return      301 https://linuxmalaysia.com$request_uri;
    }
}

Let's break down the http section directives you've provided, focusing on their impact on Nginx performance and how they relate to CPU and memory usage. I'll also offer suggestions for optimization.

These settings are within the http block, meaning they apply globally to all server blocks defined within it, unless overridden in a specific server or location block.

1. charset utf-8;

• Explanation: This directive sets the default character encoding for responses to UTF-8. Nginx will add a Content-Type header like Content-Type: text/html; charset=utf-8; to responses.
• Performance Impact:
  • Minimal CPU/Memory: The impact on CPU and memory is negligible. It's primarily a correctness and display setting for web browsers.
  • Browser Interpretation: Ensures browsers correctly interpret the characters in your web pages, preventing display issues.
• Suggestions: This is a standard and recommended setting. Keep it as utf-8; unless you have a specific legacy requirement for a different encoding.

2. sendfile on;

• Explanation: This directive enables the sendfile() system call. When sendfile is on, Nginx can directly copy data from one file descriptor (e.g., a file on disk) to another file descriptor (e.g., a network socket) without involving user-space buffers.
• Performance Impact:
  • CPU: Significantly reduces CPU overhead by eliminating unnecessary data copying between kernel space and user space. This means fewer context switches and less CPU time spent on data transfer.
  • Memory: Reduces memory usage by avoiding intermediate buffer copies. Data flows directly from disk to network.
  • I/O: Improves I/O performance, especially for serving static files, as it's a more efficient way to transfer data.
• Suggestions:
  • Keep on: For serving static content, sendfile on; is almost always recommended for performance.
  • When to turn off: If Nginx is serving files from network file systems (NFS) or if you're heavily modifying files after Nginx starts serving them (though this is rare for typical web content), you might consider turning it off or using aio threads with sendfile on (a more advanced topic for highly concurrent async I/O). However, for most setups, on is best.
  • tcp_nopush on; with sendfile on;: These two directives are often used together for optimal static file serving. tcp_nopush on; (discussed next) tells Nginx to send HTTP response headers and the beginning of the file in one go, rather than in separate packets, improving initial delivery.

3. tcp_nopup on; (Typo: Should be tcp_nopush on;)

• Explanation: This appears to be a typo and should be tcp_nopush on;. When used with sendfile on;, tcp_nopush on; enables the TCP_NOPUSH socket option. This causes Nginx to send data in full packets. Specifically, it waits until the response headers, or a full buffer of data, or the end of the file is ready, before sending it.
• Performance Impact:
  • CPU: Can slightly reduce CPU usage by sending fewer, larger packets, which reduces the number of system calls and network overhead.
  • Network Efficiency: Improves network efficiency by preventing the "Nagle's algorithm" from delaying small packets, ensuring data is packed into full segments before sending. This is particularly beneficial for initial load times of large static files.
  • Reduced Latency (initial): For the first chunk of data (headers + start of file), it helps send it more efficiently, potentially reducing perceived initial latency.
• Suggestions:
  • Correct the typo to tcp_nopush on;.
  • Use with sendfile on;: It's highly recommended to use tcp_nopush on; in conjunction with sendfile on; for static file delivery.

4. tcp_nodelay on;

• Explanation: This directive enables the TCP_NODELAY socket option, which disables Nagle's algorithm. Nagle's algorithm attempts to conserve network bandwidth by buffering small segments of data and sending them together as one larger segment.
• Performance Impact:
  • Latency: tcp_nodelay on; prioritizes latency over bandwidth efficiency for small data packets. It ensures that small packets are sent immediately without waiting for more data to accumulate.
  • CPU/Memory: The direct impact on CPU/memory is minimal. It's more about network behavior.
  • For proxy_pass: This is particularly beneficial for proxied connections (like your proxy_pass http://127.0.0.1:3000;) and real-time applications where quick responses are crucial. It ensures that the initial response and subsequent small data chunks from your backend are sent to the client immediately.
• Suggestions:
  • Keep on: For interactive web applications, proxied connections, and APIs, tcp_nodelay on; is generally recommended for better responsiveness.
  • Conflict with tcp_nopush: Note that tcp_nopush and tcp_nodelay serve different purposes and can sometimes seem contradictory. tcp_nopush optimizes sending large chunks efficiently (like initial static file segments), while tcp_nodelay optimizes sending small chunks immediately. For most web servers, using both is fine: tcp_nopush helps with the initial large send, and then tcp_nodelay ensures subsequent interactive or smaller data packets flow quickly.

5. server_tokens off;

• Explanation: This directive suppresses the Nginx version number from error pages and Server response headers.
• Performance Impact:
  • Security: Primarily a security measure. It makes it harder for attackers to identify your exact Nginx version and exploit known vulnerabilities.
  • Minimal CPU/Memory: Has virtually no impact on CPU or memory usage.
• Suggestions: Keep off. This is a good security practice and has no negative performance implications.

6. types_hash_max_size 2048;

• Explanation: This directive sets the maximum size of the hash table used to store MIME types (e.g., text/html, image/jpeg). Nginx uses this hash table to quickly look up the Content-Type header for files based on their extensions as defined in mime.types.
• Performance Impact:
  • CPU: A well-sized hash table reduces the number of collisions and thus the CPU time needed to look up MIME types. If the hash table is too small, lookups become slower.
  • Memory: The size of this table directly affects memory usage.
• Suggestions (CPU/Memory Balance):
  • 2048 is a common and usually sufficient value.
  • Increase if needed: If you have a very large number of custom MIME types or dynamically generated types, you might consider increasing this. However, for most standard web applications, 2048 or even 1024 is usually enough.
  • Check error logs: If Nginx logs warnings about "could not build types_hash, you should increase types_hash_max_size" during startup or reload, then you absolutely need to increase it.
  • Rule of thumb: Increase in powers of 2.

7. types_hash_bucket_size 64;

• Explanation: This directive defines the size of the hash bucket used for the MIME types hash table. This must be a power of 2 (e.g., 32, 64, 128, etc.). The default is often 64 or 128, depending on the architecture.
• Performance Impact:
  • CPU/Memory: Similar to types_hash_max_size, an appropriately sized bucket reduces collisions and improves lookup speed. If the bucket size is too small, multiple entries might map to the same bucket, requiring a linear scan within the bucket, which is slower.
  • Optimization: It should be a multiple of the processor's cache line size (often 64 bytes).
• Suggestions (CPU/Memory Balance):
  • 64 is generally a good default and matches common cache line sizes.
  • Increase if needed: If you encounter warnings related to the types_hash_bucket_size (which is less common than types_hash_max_size warnings), or if you have an exceptionally large types_hash_max_size and notice performance issues, you might increase it to 128. However, 64 is fine for most cases.

8. client_max_body_size 16M;

• Explanation: This directive sets the maximum allowed size of the client request body. If a client sends a request with a body larger than this limit (e.g., during a file upload), Nginx will return a 413 Request Entity Too Large error.
• Performance Impact:
  • Memory: Nginx will buffer the client request body in memory (and potentially disk if it exceeds buffer limits) up to this size. Setting this very high without sufficient memory could lead to high memory consumption, especially with many simultaneous large uploads.
  • Security/DDoS: Acts as a basic protection against denial-of-service (DoS) attacks where an attacker tries to consume server resources by sending extremely large request bodies.
• Suggestions (CPU/Memory Balance):
  • 16M is a reasonable default for many web applications.
  • Adjust based on needs:
    • If your application requires larger file uploads (e.g., image galleries, video uploads), you'll need to increase this value (e.g., 50M, 100M, 500M, 1G).
    • If your application does not handle file uploads or only small forms, you can reduce this value (e.g., 1M, 5M) to save memory and add a layer of DoS protection.
  • Memory implications: Be aware that increasing this significantly will mean Nginx needs more memory to buffer large requests. Ensure your server has enough RAM.

Overall Performance Summary for this HTTP Section:

These settings are generally well-chosen for performance:

• sendfile on, tcp_nopush on, tcp_nodelay on: Excellent for efficient data transfer, reducing CPU load, and improving perceived latency, especially for static files and proxied connections.
• charset utf-8, server_tokens off: Good defaults for correctness and security, with negligible performance impact.
• types_hash_max_size, types_hash_bucket_size: Fine for most use cases; only adjust if Nginx logs warnings.
• client_max_body_size: A sensible default. Tune this based on your application's specific upload requirements and available memory.

Your http block looks solid for good general performance. The main area for adjustment based on your specific application needs (especially for file uploads) would be client_max_body_size.

You're asking about Nginx's rate limiting feature, which is a powerful tool for protecting your server from abuse, brute-force attacks, and ensuring fair resource usage among clients.

Let's break down these two directives:

1. limit_req_log_level warn;

• Explanation: This directive specifies the logging level for requests that are delayed or rejected by the limit_req (request limiting) module.
  • warn: This means that if a request is delayed or rejected due to rate limiting, a message will be written to the error_log (which you have configured as /var/log/nginx/error.log warn;) with a warn severity level.
• Performance Impact / Benefit:
  • Visibility: This is crucial for monitoring. It allows you to see when your rate limits are being hit, either legitimately by high traffic or potentially by malicious activity (e.g., a bot attempting to brute-force logins).
  • Debugging: Helps you debug your rate limit settings. If legitimate users are being rate-limited unexpectedly, these logs will tell you.
  • Minimal Overhead: The act of logging has a very minimal performance overhead.
• Suggestions:
  • Keep warn or info: warn is a good default. It's high enough to be noticeable but not so low (like debug) that it floods your logs. For very noisy environments, you might even consider error if you only want to log outright rejections, but warn is generally more informative.

2. limit_req_zone $binary_remote_addr zone=login:10m rate=10r/m;

• Explanation: This is the core directive that defines a rate limiting zone. It tells Nginx how to track and limit incoming requests.
  • $binary_remote_addr: This is the key by which requests will be counted.
    • $remote_addr: Represents the client's IP address.
    • $binary_remote_addr: Is a binary representation of the client's IP address. It's more memory-efficient when storing the key in the shared memory zone, especially for IPv6 addresses. Using the binary form is generally recommended for rate limiting.
    • Purpose: By using the client's IP, Nginx tracks requests per unique client IP address.
  • zone=login:10m: This defines a shared memory zone where the state of each key (IP address) and its request count will be stored.
    • login: This is the arbitrary name of the zone. You'll reference this name later in limit_req directives.
    • 10m: Specifies the size of the shared memory zone. 10m (10 megabytes) can store state for approximately 160,000 active IP addresses (assuming 64 bytes per state entry).
      • Memory Impact: This directly consumes memory. If you expect a massive number of unique clients within the zone's active period, you might need a larger zone. If it's too small, Nginx might log warnings about being unable to store new keys.
  • rate=10r/m: This sets the maximum request rate allowed for keys within this zone.
    • 10r/m: Means 10 requests per minute.
    • Other examples: 1r/s (1 request per second), 60r/m (60 requests per minute, which is equivalent to 1r/s).
• Performance Impact / Benefit:
  • Resource Protection: This is the primary benefit. By limiting the rate of requests from individual clients, you prevent a single (or few) misbehaving or malicious clients from overwhelming your server resources (CPU, memory, bandwidth, backend application). This ensures your server remains responsive for legitimate users.
  • DDoS/Brute-Force Mitigation: Excellent for mitigating basic DDoS attacks and, specifically, brute-force login attempts (which is why your zone is named login). If a bot tries to hit your login page thousands of times a minute, Nginx will start rejecting most of those requests, protecting your backend.
  • Fair Usage: Promotes fair usage by preventing a few clients from monopolizing resources.
  • CPU/Memory Overhead: While beneficial, rate limiting does introduce some CPU overhead because Nginx has to:
    • Look up the client's IP in the shared memory zone for every request.
    • Update the request count.
    • Potentially delay or reject the request.
    • However, this overhead is usually minimal compared to the cost of letting an un-rate-limited attack hit your backend application. The memory consumption is determined by the zone size.
• Suggestions for limit_req_zone:
  • Zone Size (10m): 10m is a good starting point. You can adjust this based on the number of unique clients you expect to be hitting the rate-limited endpoint concurrently. If you run out of space, Nginx will log "overflow" warnings.
  • Rate (10r/m): 10r/m is quite strict for a general endpoint but very suitable for a login page to prevent brute-force attacks.
    • For general API endpoints, you might allow higher rates (e.g., 60r/m or 1r/s per client, or even higher depending on your API's nature).
    • Bursts (burst parameter): You might consider adding a burst parameter. For example, rate=10r/m burst=5;. This allows a client to make a burst of up to 5 requests above the defined rate before requests are delayed or rejected. This helps accommodate legitimate users who might sometimes exceed the average rate for a brief moment (e.g., loading a page with many assets that trigger the limit).
    • nodelay parameter: You can add nodelay with burst. rate=10r/m burst=5 nodelay;. If nodelay is specified, the requests exceeding the rate will be processed immediately (up to the burst size), but the delay for future requests will be increased. Without nodelay, exceeding burst size would cause requests to be delayed.
  • Application: Remember that limit_req_zone defines the zone, but it doesn't apply the limit. You need to use the limit_req directive within a location block to apply it:

    location /login {
        limit_req zone=login burst=5 nodelay; # Apply the limit defined above
        # ... proxy_pass to your login backend ...
    }

    This is why the zone is named login, implying it's intended for your login endpoint.

How it relates to CPU and Memory:

• CPU: The CPU overhead comes from the lookup and update operations in the shared memory zone. A well-designed hash table (which Nginx uses for these zones) minimizes this. limit_req_zone itself has minimal CPU impact; the limit_req directive (when active) introduces the per-request CPU cost.
• Memory: The zone=login:10m directly allocates 10MB of shared memory for Nginx processes to store the state of tracked IP addresses. This memory is consumed regardless of how many clients are currently active, as it's pre-allocated for the hash table. Ensure you have enough available RAM for these zones, especially if you define many large zones.

In summary, these directives are vital for robust server operation, providing a critical layer of defense against abuse and ensuring consistent performance for legitimate users by shedding excess load at the Nginx layer before it reaches your backend application. Your current settings are a good starting point, especially the rate=10r/m for a login zone, indicating an intention to protect against brute-force attacks.

Let's delve into the SSL-related settings in your Nginx configuration. These are crucial for securing your website and also play a significant role in performance, especially in the context of HTTPS traffic.

1. ssl_session_timeout 1d;

• Explanation: This directive sets the timeout for the SSL/TLS session cache. Once a client and server establish an SSL/TLS connection, they negotiate various parameters, including encryption keys. Session caching allows subsequent connections from the same client to reuse these negotiated parameters, skipping the computationally expensive full TLS handshake. 1d means 1 day.
• Performance Impact (CPU):
  • Reduces CPU Load: The TLS handshake is CPU-intensive, involving asymmetric cryptography (RSA or ECC). By allowing sessions to be reused, Nginx avoids performing a full handshake for every new connection from a returning client within the timeout period. This significantly reduces CPU overhead, especially on busy servers with many recurring visitors.
  • Faster Connection Establishment: Clients also benefit from faster connection establishment, as they don't have to go through the full handshake process again.
• Suggestions:
  • 1d (1 day) is a very good, standard value. It balances security (not keeping old sessions around indefinitely) with performance (allowing common users to reuse sessions for a reasonable period).
  • Avoid setting it too low (e.g., a few minutes) as it negates the benefit of session caching.

2. ssl_session_cache shared:SSL:10m;

• Explanation: This directive configures the shared memory cache for SSL/TLS sessions.
  • shared:: Indicates that the cache will be shared among all Nginx worker processes. This is essential, otherwise, a client connecting to a different worker process would not be able to reuse a session established with another worker.
  • SSL:: This is an arbitrary name for the cache zone.
  • 10m: Specifies the size of the shared memory cache in megabytes. 10m can store approximately 40,000 to 80,000 sessions (depending on session ticket size). Each session ticket is around 256 bytes to 512 bytes.
• Performance Impact (Memory & CPU):
  • Memory Usage: This directly allocates 10MB of RAM for the session cache. This memory is shared among worker processes.
  • CPU: Works in conjunction with ssl_session_timeout to enable session reuse, thus reducing CPU load from TLS handshakes. A larger cache can store more sessions, increasing the hit rate for session reuse.
• Suggestions:
  • shared:SSL:10m is a robust and commonly recommended size.
  • Monitoring: If you have very high traffic and observe that your session cache hit rate is low (you'd need Nginx's stub_status module to see this), you might consider increasing the cache size, but 10m is typically sufficient for most websites.
  • Too large a cache might consume unnecessary memory without proportional benefits, as old or rarely used sessions eventually get purged.

3. ssl_session_tickets off;

• Explanation: This directive controls the use of TLS session tickets (also known as stateless session resumption).
  • TLS Session Tickets: A mechanism where the server encrypts session information into a "ticket" and sends it to the client. The client stores this ticket and presents it on subsequent connections. The server then decrypts the ticket to resume the session, without needing to store the session state on the server-side.
  • off: Disables this feature.
• Performance Impact (CPU & Security):
  • CPU (Potential Benefit if on): If on, it can further reduce CPU load on the server, especially in large, distributed environments or those with high connection churn, because the server doesn't need to look up session state in its local memory.
  • Security (Reason for off): The primary reason to turn ssl_session_tickets off is security. If the secret key used to encrypt these session tickets is compromised, an attacker could decrypt past session tickets and potentially decrypt past traffic. This is a significant concern for Perfect Forward Secrecy (PFS). While PFS protects the long-term private key, compromised session ticket keys can undermine its benefits for tickets issued with that key. Many security guides recommend disabling them or ensuring strong key rotation practices.
• Suggestions:
  • Keep off (Recommended for Security): For most deployments, especially with modern TLS 1.3 (which has better 0-RTT mechanisms and often relies less on explicit session tickets), keeping ssl_session_tickets off is the generally recommended and more secure approach to ensure Perfect Forward Secrecy is not compromised by potential ticket key exposure.
  • Alternative: ssl_session_ticket_key rotation: If you absolutely need the performance benefit and understand the risks, you could enable it and implement a robust system for frequently rotating your ssl_session_ticket_key files.

4. ssl_protocols TLSv1.3; (Mozilla Modern configuration)

• Explanation: This directive specifies the SSL/TLS protocols that Nginx will allow for secure connections.
  • TLSv1.3: This is the latest and most secure version of the TLS protocol.
• Performance Impact (CPU & Latency):
  • CPU (Lower): TLS 1.3 has a simpler and faster handshake process compared to previous TLS versions, requiring fewer round trips. This reduces CPU overhead during handshake.
  • Latency (Lower): The reduced number of round trips in the handshake significantly lowers connection establishment latency, leading to faster perceived page loads.
  • Security: TLS 1.3 removes support for older, less secure features and ciphers, making your connection more robust against various attacks.
  • Cipher Suites: With TLSv1.3, Nginx automatically selects strong, modern cipher suites. Explicitly listing ssl_ciphers (as was common for older TLS versions) is less critical or even redundant for TLS 1.3 as it has a much smaller, stricter set of ciphers.
• Suggestions:
  • Excellent setting: This is the ideal and most modern setting. Keep TLSv1.3;
  • Browser Compatibility: While TLS 1.3 is widely supported by modern browsers, some very old clients might not support it. If you need to support extremely old browsers (e.g., IE 10 or older Android versions), you might reluctantly add TLSv1.2 as well, but this is increasingly rare. Your current setup prioritizes security and modern performance.

5. ssl_stapling on; & ssl_stapling_verify on; (OCSP Stapling)

• Explanation: These directives enable and verify OCSP Stapling.
  • OCSP (Online Certificate Status Protocol): A protocol used by browsers to check if an SSL certificate has been revoked. Normally, the browser has to contact the CA's OCSP server directly, which adds latency and can be a privacy concern.
  • OCSP Stapling: The web server (Nginx) itself queries the CA's OCSP server periodically to get the certificate's revocation status. It then "staples" this signed OCSP response to its own TLS handshake. When a browser connects, it receives this pre-validated status directly from Nginx, avoiding the need to make a separate request to the OCSP server.
  • ssl_stapling on;: Enables Nginx to perform the OCSP query and staple the response.
  • ssl_stapling_verify on;: Ensures that the stapled OCSP response is valid and signed by the certificate authority.
• Performance Impact (Latency & Reliability):
  • Reduced Latency: Significantly reduces connection establishment latency for clients, as they don't have to perform an additional DNS lookup and HTTP request to the CA's OCSP server. This speeds up the TLS handshake.
  • Improved Reliability: Reduces reliance on the CA's OCSP server being quickly reachable and responsive for every client.
  • Privacy: Improves user privacy by preventing browsers from directly telling the CA which sites they are visiting.
  • CPU/Memory (Minimal): Nginx does periodically query the OCSP server itself, which consumes minimal CPU and memory resources.
• Suggestions:
  • Keep on: Both ssl_stapling on; and ssl_stapling_verify on; are highly recommended for performance and security.

6. resolver ... valid=60s; and resolver_timeout 2s;

• Explanation: These directives configure how Nginx resolves domain names to IP addresses, which is crucial for OCSP stapling, proxy_pass to hostnames, and other features requiring DNS lookups.
  • resolver: Specifies a list of DNS servers Nginx should use. You have a very comprehensive list here, including Cloudflare (1.1.1.1, 1.0.0.1), Google (8.8.8.8, 8.8.4.4), OpenDNS, Quad9, and Alternate DNS, with both IPv4 and IPv6 addresses.
  • valid=60s;: Sets the validity period for Nginx's DNS cache. After 60 seconds, Nginx will re-query the DNS server for that hostname.
  • resolver_timeout 2s;: Sets the timeout for a DNS query. If a DNS server doesn't respond within 2 seconds, Nginx will try the next one.
• Performance Impact (Latency & Reliability):
  • Reduced Latency (Caching): The valid=60s helps by caching DNS responses. Nginx doesn't need to perform a new DNS lookup for every request that relies on a hostname (like OCSP servers or your proxy_pass if it used a hostname instead of 127.0.0.1). This speeds up lookups significantly.
  • Reliability: Having multiple diverse DNS servers (as you do) improves the reliability of lookups. If one resolver is down or slow, Nginx can quickly fall back to another.
  • Timeout: A short resolver_timeout ensures that Nginx doesn't wait too long for a non-responsive DNS server, failing over quickly.
• Suggestions:
  • Excellent resolver list: Your list is extensive and provides great redundancy.
  • valid=60s is a good balance: It's frequent enough to pick up DNS changes relatively quickly but caches long enough to reduce unnecessary lookups. You could potentially increase this for very stable hostnames (e.g., 300s or 3m) to save a tiny bit more CPU, but 60s is perfectly fine.
  • resolver_timeout 2s is appropriate: Ensures quick failover if a DNS server is slow.

Overall SSL Performance and Security:

Your SSL configuration is excellent and follows modern best practices for both performance and security.

• By using TLSv1.3 and enabling ssl_session_cache with a reasonable timeout, you minimize CPU overhead from handshakes.
• Disabling ssl_session_tickets is a strong security choice that avoids potential PFS compromises.
• OCSP stapling significantly improves perceived performance by reducing client-side latency.
• The robust resolver configuration ensures reliable and fast DNS lookups for all SSL-related operations.

You've got a very solid setup here!

Let's break down this map directive for the $proxy_forwarded_elem variable. This setting is all about correctly constructing the Forwarded HTTP header when Nginx is acting as a reverse proxy.

---

Understanding the Forwarded Header

When a client (like your web browser) connects to Nginx, Nginx sees the client's original IP address ($remote_addr). However, if Nginx then proxies that request to another backend server (your 127.0.0.1:3000 application in this case), the backend server will only see Nginx's IP address (e.g., 127.0.0.1).

To ensure the backend application knows the original client's IP address (and potentially other proxy information), various headers are used. Historically, X-Forwarded-For has been common. However, the Forwarded header (defined in RFC 7239) is the modern and standardized way to pass this information.

The Forwarded header can include several pieces of information, but the most common is for=<client-ip>, indicating the original client's identifier.

---

Explaining the map Block

map $remote_addr $proxy_forwarded_elem {
    # IPv4 addresses can be sent as-is
    ~^[0-9.]+$        "for=$remote_addr";

    # IPv6 addresses need to be bracketed and quoted
    ~^[0-9A-Fa-f:.]+$ "for=\"[$remote_addr]\"";

    # Unix domain socket names cannot be represented in RFC 7239 syntax
    default           "for=unknown";
}

This map directive defines a new variable called $proxy_forwarded_elem. Its value depends on the value of $remote_addr (the client's original IP address).

1. map $remote_addr $proxy_forwarded_elem { ... }:

   • $remote_addr: This is a built-in Nginx variable that holds the IP address of the client that made the request to Nginx.
   • $proxy_forwarded_elem: This is the new variable that will be created and its value set by this map. It will represent one part of the Forwarded header.

2. ~^[0-9.]+$ "for=$remote_addr"; (For IPv4 addresses):

   • ~^[0-9.]+$: This is a regular expression pattern that matches typical IPv4 addresses (e.g., 192.168.1.1, 10.0.0.5).
   • If $remote_addr matches an IPv4 pattern, the $proxy_forwarded_elem variable will be set to "for=$remote_addr".
   • Example: If the client's IP is 192.0.2.1, then $proxy_forwarded_elem becomes "for=192.0.2.1".

3. ~^[0-9A-Fa-f:.]+$ "for=\"[$remote_addr]\""; (For IPv6 addresses):

   • ~^[0-9A-Fa-f:.]+$: This regular expression matches typical IPv6 addresses (e.g., 2001:0db8::1).
   • If $remote_addr matches an IPv6 pattern, the $proxy_forwarded_elem variable will be set to "for=\"[$remote_addr]\"".
   • Why the brackets and quotes? RFC 7239 specifies that IPv6 addresses in the Forwarded header's for parameter must be enclosed in square brackets [] and then quoted "" if they contain colons (which IPv6 addresses always do). This ensures correct parsing.
   • Example: If the client's IP is 2001:db8::1, then $proxy_forwarded_elem becomes "for="[2001:db8::1]"".

4. default "for=unknown";:

   • default: This is the fallback rule. If $remote_addr doesn't match either an IPv4 or IPv6 pattern (e.g., if Nginx is configured to use Unix domain sockets for client connections, or if $remote_addr is somehow malformed), then $proxy_forwarded_elem will be set to "for=unknown".
   • Reasoning: Unix domain socket names, for instance, cannot be represented in the RFC 7239 for syntax, so unknown is a suitable placeholder.

---

How it's Used in Your Configuration

You'll see this $proxy_forwarded_elem variable used in another map directive (map $http_forwarded $proxy_add_forwarded) and ultimately within your proxy_set_header directives, like this:

proxy_set_header Forwarded $proxy_add_forwarded;

This ensures that the Forwarded header sent to your backend application is correctly formatted according to RFC 7239, whether the original client used an IPv4 or IPv6 address. This is important for your backend application to accurately log, track, or make decisions based on the actual client's IP address rather than just Nginx's IP.

---

Performance Impact

• Minimal CPU/Memory: The map directive itself involves simple string matching and variable assignment, which has a very low CPU and memory overhead per request. It's a highly efficient way to conditionally set variable values in Nginx.
• Correctness and Compatibility: Its primary benefit is ensuring the Forwarded header is correctly formatted, which helps with compatibility and proper logging/functionality on your backend application, avoiding parsing errors or misidentification of client IPs.

In essence, this map ensures your backend always gets the client's true IP in a standardized format, regardless of whether it's IPv4 or IPv6.

Okay, this map directive is significantly more complex than the previous one, but it serves a very important purpose: correctly handling and appending to the standardized Forwarded HTTP header in a multi-proxy environment.

This map builds upon the $proxy_forwarded_elem variable that we just discussed.

---

The Problem: Multiple Proxies

Imagine this chain:

Client -> Proxy A (e.g., a CDN or Load Balancer) -> Nginx -> Backend Application

• Client sends a request.
• Proxy A receives it, adds its own Forwarded header (or X-Forwarded-For), and forwards it to Nginx.
• Nginx receives the request. It needs to add its own information to the Forwarded header before passing it to the backend, without overwriting what Proxy A already added.

This is precisely what this map aims to achieve for the Forwarded header (RFC 7239).

---

Explaining the map Block

map $http_forwarded $proxy_add_forwarded {

    # If the incoming Forwarded header is syntactically valid, append to it
    "~^(,[ \\t]*)*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*([ \\t]*,([ \\t]*([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?(;([!#$%&'*+.^_`|~0-9A-Za-z-]+=([!#$%&'*+.^_`|~0-9A-Za-z-]+|\"([\\t \\x21\\x23-\\x5B\\x5D-\\x7E\\x80-\\xFF]|\\\\[\\t \\x21-\\x7E\\x80-\\xFF])*\"))?)*)?)*$" "$http_forwarded, $proxy_forwarded_elem";

    # Otherwise, replace it
    default "$proxy_forwarded_elem";
}

This map directive defines a new variable called $proxy_add_forwarded. Its value depends on the $http_forwarded variable, which contains the incoming Forwarded header from the client (or the previous proxy).

1. map $http_forwarded $proxy_add_forwarded { ... }:

   • $http_forwarded: This is a built-in Nginx variable that captures the value of the Forwarded header sent by the client.
   • $proxy_add_forwarded: This is the new variable that Nginx will set. Its purpose is to be the final Forwarded header value sent to the backend.

2. The Long Regular Expression Line:

   • The Match ("~^...*$"): This incredibly long regular expression attempts to validate if the incoming $http_forwarded header is syntactically valid according to RFC 7239. It's designed to match the various components and formatting rules of the Forwarded header (which can include for, by, proto, and host parameters, separated by semicolons and commas).
   • The Result ("$http_forwarded, $proxy_forwarded_elem"): If the incoming Forwarded header is valid, then the $proxy_add_forwarded variable will be set to:
     • The original $http_forwarded header value.
     • Followed by a comma and a space , .
     • Followed by the $proxy_forwarded_elem variable (which, as we discussed, contains for=<client-ip> correctly formatted for IPv4/IPv6).
   • Purpose: This map entry effectively says: "If a Forwarded header already exists and it looks correct, then append our (Nginx's) for= information to it." This maintains the proxy chain information.

3. default "$proxy_forwarded_elem";:

   • The Match (default): If the incoming $http_forwarded header is not present, or if it is present but does not match the strict RFC 7239 validation regex (meaning it's syntactically incorrect or malformed), then this default rule applies.
   • The Result ("$proxy_forwarded_elem"): In this case, $proxy_add_forwarded will simply be set to the value of $proxy_forwarded_elem.
   • Purpose: This means: "If there's no valid Forwarded header coming in, or if it's messed up, then just start a new one with our (Nginx's) for= information." This prevents propagating malformed headers and ensures your backend at least gets some Forwarded information from Nginx.

---

How it's Used in Your Configuration

Finally, this $proxy_add_forwarded variable is used in your proxy_set_header directive:

proxy_set_header Forwarded $proxy_add_forwarded;

This is how the correctly constructed Forwarded header (either appended or newly created) is sent to your backend application (e.g., http://127.0.0.1:3000).

---

Performance Impact

• Minimal CPU/Memory: Similar to the previous map directive, the map operation itself is highly optimized in Nginx. The main overhead comes from the regular expression matching. While the regex is complex, it's compiled efficiently by Nginx. For each request, this small amount of processing happens to determine the correct Forwarded header.
• Correctness and Observability: The primary benefit here is correctness and ensuring that the entire proxy chain is accurately represented in the Forwarded header. This is invaluable for:
  • Logging: Accurately logging the original client's IP and the path through proxies.
  • Analytics: Correctly attributing traffic.
  • Security: Tracking source IPs for security tools or rate limiting at the application level.
  • Debugging: Understanding the flow of requests through your infrastructure.

In essence, this map provides a robust and RFC-compliant way for Nginx to participate in a multi-proxy environment, ensuring that the backend application receives accurate and complete Forwarded header information. This is a best practice for modern web infrastructure.

---

Nginx Cache Configuration: proxy_cache_path Explained

You're asking about the proxy_cache_path directive, which is the foundational setting for enabling and managing caching in Nginx when it acts as a reverse proxy. This directive defines a cache zone, telling Nginx where to store cached content and how to manage it.

Let's break down each part of this crucial line:

proxy_cache_path /var/cache/nginx levels=1:2 keys_zone=my_cache:10m max_size=1g inactive=60m use_temp_path=off;

1. /var/cache/nginx

• Explanation: This is the path to the root directory where Nginx will store its cache files on your server's file system.
• Performance Impact:
  • Disk I/O: The performance of your cache heavily depends on the speed of the disk where this directory resides. An SSD (Solid State Drive) will offer significantly better read/write performance for caching compared to a traditional HDD (Hard Disk Drive).
  • Permissions: Nginx's worker processes (running as www-data in your setup) must have write access to this directory to create and store cache files. If permissions are incorrect, caching will fail.
• Suggestions:
  • Ensure this directory exists (sudo mkdir -p /var/cache/nginx).
  • Set appropriate ownership and permissions (sudo chown -R www-data:www-data /var/cache/nginx).
  • If possible, place this on a fast local disk (SSD is ideal).

2. levels=1:2

• Explanation: This defines the directory hierarchy for the cache. Nginx stores cache files in a structured way to avoid having too many files in a single directory, which can be inefficient for the file system.
  • 1:2 means Nginx will create two levels of subdirectories based on the MD5 hash of the cache key.
    • The first level will have 1 character (0-F).
    • The second level will have 2 characters (00-FF).
  • For example, a cached file might be stored at /var/cache/nginx/c/29/abcdef12345....
• Performance Impact:
  • File System Efficiency: This is crucial for performance with large caches. Without proper directory levels, a single directory could contain millions of files, leading to slow lookups and I/O operations for the operating system.
  • Optimal Setting: levels=1:2 is a standard and highly recommended setting for good performance, balancing directory depth with the number of subdirectories.
• Suggestions: Stick with levels=1:2. Rarely needs adjustment.

3. keys_zone=my_cache:10m

• Explanation: This defines a shared memory zone for storing the cache keys and metadata (like HTTP headers) for all active cached items.
  • my_cache: This is the name of your cache zone. You'll use this name in proxy_cache my_cache; directives within your location blocks to enable caching.
  • 10m: Specifies the size of this shared memory zone in megabytes. Each entry (cache key and metadata) typically takes around 64-128 bytes. A 10m zone can hold metadata for roughly 80,000 to 160,000 active cached items.
• Performance Impact (Memory & CPU):
  • Memory Consumption: This directly allocates 10MB of RAM that is shared among all Nginx worker processes.
  • CPU (Lookup Speed): This zone acts as an in-memory index for your disk cache. When a request comes in, Nginx first checks this fast in-memory hash table. If a match is found (a "cache hit"), Nginx knows where to find the file on disk. This significantly reduces CPU cycles and latency compared to having to search the disk every time.
  • Cache Efficiency: If this zone is too small for the number of items you frequently cache, Nginx might have to evict entries prematurely from the memory index, even if the content is still on disk, leading to more "misses" and disk lookups.
• Suggestions:
  • 10m is a good starting point for keys_zone.
  • Monitor: If Nginx logs warnings about the keys_zone being full or cache "overflows," you might need to increase this size. The amount of memory used here should align with the number of unique URLs you expect to cache.

4. max_size=1g

• Explanation: This directive sets the maximum size of the disk cache. Once the cache grows beyond this limit, Nginx will start removing the least recently used (LRU) files to free up space.
  • 1g: Specifies a maximum cache size of 1 gigabyte.
• Performance Impact (Disk Space & Efficiency):
  • Disk Usage: Directly controls how much disk space your cache consumes.
  • Cache Hit Ratio: A larger max_size allows Nginx to store more content, potentially leading to a higher cache hit ratio (meaning more requests are served from cache, reducing backend load).
  • Eviction Overhead: When the max_size is reached, Nginx's cache manager process starts deleting old files. This process consumes some CPU and disk I/O, but it's typically efficient and runs in the background.
• Suggestions:
  • Based on Disk Space: Choose a size appropriate for your available disk space.
  • Based on Content Volume: Consider the total size of the static and dynamic content you expect to cache. For many websites, 1GB is a decent start. Larger sites with lots of images or media might need 10GB, 50GB, or even more.

5. inactive=60m

• Explanation: This directive specifies how long a cached item can remain in the cache without being accessed. If an item is not requested for 60m (60 minutes), it will be removed by the cache manager process, regardless of whether the max_size has been reached.
• Performance Impact (Disk Space & Freshness):
  • Disk Space Management: Helps to automatically free up disk space from stale or unpopular content.
  • Cache Freshness: Prevents your cache from filling up with old content that is no longer frequently requested.
  • CPU: The cache manager process runs periodically to check for inactive items, consuming minimal CPU.
• Suggestions:
  • 60m (1 hour) is a common and usually good value.
  • Adjust based on content volatility:
    • If your content changes frequently, you might reduce this (e.g., 30m).
    • If your content is very stable and rarely changes, you could increase it (e.g., 1d or 7d) to keep items in cache longer and potentially improve hit rates for less frequent visitors.

6. use_temp_path=off;

• Explanation: This directive is highly recommended for performance. By default, Nginx first writes cached files to a temporary file in a separate proxy_temp_path directory (often /var/lib/nginx/tmp), then renames it to the cache directory. use_temp_path=off; prevents this.
• Performance Impact (Disk I/O & CPU):
  • Reduced Disk I/O: When off, Nginx writes directly to the cache directory. This avoids an extra disk write (to temp) and a rename operation, significantly reducing disk I/O, especially on busy servers or those using SSDs. This is a crucial optimization.
  • CPU: Reduces CPU overhead associated with file copying and renaming.
  • Atomicity: While off is great for performance, be aware that if the Nginx process crashes while writing a file, a partial file might be left in the cache directory. However, Nginx is generally stable, and the performance gain usually outweighs this minor risk.
• Suggestions: Always keep use_temp_path=off; unless you have a very specific reason not to (e.g., extreme concern about partial files after a crash on a highly sensitive system, which is rare).

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CPU and Memory Considerations for proxy_cache_path

• CPU: The CPU impact comes from hash lookups in keys_zone, background cache management (inactive item removal, LRU eviction), and the overhead of writing files to disk. sendfile on; (in the http block) helps significantly reduce CPU when serving cached content.
• Memory:
  • The keys_zone directly consumes the specified amount of RAM (10m in your case). This memory is pre-allocated.
  • Nginx also uses some memory for buffering requests and responses, but proxy_cache_path directly relates to the shared memory cache for its index.
• Overall: Your proxy_cache_path configuration is very well-tuned for general web serving, balancing memory usage, disk space, and performance. The use_temp_path=off is a particularly important optimization.

By having this cache configured, you enable Nginx to serve content much faster, reduce the load on your backend application, and improve the overall responsiveness of your website for visitors in Cyberjaya, Selangor, Malaysia, and globally.

Let's dive into the location / block of your Nginx configuration, which is where the magic of reverse proxying and caching for your main application happens. This block is critical as it defines how Nginx handles all requests that don't match more specific location directives (like those for static assets).

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Reverse Proxying Directives

These lines tell Nginx to forward requests to your backend application:

• proxy_pass http://127.0.0.1:3000;

  • Explanation: This is the core of the reverse proxy. It tells Nginx to forward all requests matching this location block to your backend server running on http://127.0.0.1:3000. So, when someone visits linuxmalaysia.com, Nginx fetches the content from your application and serves it back to the user.
  • Performance Impact: This enables your web application to be served by Nginx, which is more efficient at handling connections and static content than most application servers. It allows you to run your application server on a private port, increasing security.

• proxy_set_header Host $host;

  • Explanation: This sets the Host header that Nginx sends to your backend. $host is an Nginx variable that automatically resolves to the incoming Host header from the client (e.g., linuxmalaysia.com). Without this, your backend might receive Host: 127.0.0.1:3000, which could cause issues if your application relies on the original hostname (e.g., for routing or virtual hosting).
  • Performance Impact: Ensures your application functions correctly, preventing errors or misconfigurations that would degrade performance or availability.

• proxy_http_version 1.1;

  • Explanation: This sets the HTTP version used for the connection between Nginx and your backend server. HTTP/1.1 supports persistent connections (Keep-Alive).
  • Performance Impact: Important for keeping the connection to your backend alive for multiple requests, reducing the overhead of establishing new TCP connections for every request. This improves efficiency and reduces latency, especially for dynamic applications.

• proxy_cache_bypass $http_upgrade;

  • Explanation: This directive tells Nginx not to serve from cache if the request contains the $http_upgrade header. This is essential for WebSocket connections. When a browser tries to upgrade a connection to a WebSocket, Nginx needs to pass that request directly to the backend without trying to serve it from cache, as WebSockets are real-time, non-cacheable connections.
  • Performance Impact: Ensures correct functionality for WebSockets and other upgrade protocols, preventing broken connections. It's a specialized directive for maintaining the integrity of such connections.

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Nginx Cache Application Directives

These lines enable and configure the caching behavior for the content served through this location block:

• proxy_cache my_cache;

  • Explanation: This is the directive that activates caching for this location block. It references the my_cache zone you defined earlier with proxy_cache_path. All responses from your backend for requests handled by this location will attempt to be cached in the my_cache zone.
  • Performance Impact: This is the primary driver of performance improvement. Once content is cached, Nginx can serve it directly from disk (or even memory, via kernel buffers), bypassing your backend application entirely for subsequent requests. This drastically reduces backend load, CPU, memory, and database usage, leading to much faster response times.

• proxy_cache_valid 200 302 10m;

  • Explanation: This specifies that successful HTTP responses (status codes 200 OK and 302 Found) should be cached for 10m (10 minutes). After 10 minutes, the cached entry becomes "stale" and Nginx will revalidate it with the backend.
  • Performance Impact: Controls the freshness of your cached content. Longer validity times increase cache hit rates (more performance benefit) but mean content might be slightly less fresh.
  • Suggestion: Adjust this based on how frequently your content changes. For highly dynamic content, you might use a shorter time (e.g., 1m or 5m). For mostly static pages from your application, 10m is reasonable.

• proxy_cache_valid 404 1m;

  • Explanation: This tells Nginx to cache 404 Not Found responses for 1m (1 minute).
  • Performance Impact: This is a great optimization for reducing load from "bad" requests or bots probing your server for non-existent pages. Instead of hitting your backend for every 404, Nginx can serve the cached 404 response directly for a short period.
  • Suggestion: Keep this. It helps protect your backend from excessive requests for invalid URLs.

• proxy_cache_key "$scheme$proxy_host$request_uri";

  • Explanation: This defines the unique key used to store and retrieve items from the cache.
    • $scheme: The protocol (http or https).
    • $proxy_host: The Host header sent to the backend (your domain name).
    • $request_uri: The full request URI (path + query string, e.g., /articles/nginx?id=123).
  • Performance Impact: Ensures that different URLs (or the same URL requested over HTTP vs. HTTPS) are cached as distinct items. This is crucial for correct cache behavior. Using a comprehensive key maximizes the likelihood of caching the correct content.
  • Suggestion: This is a standard and robust cache key. Stick with it unless you have very specific caching needs (e.g., excluding certain query parameters).

• proxy_cache_min_uses 1;

  • Explanation: This directive specifies that a response will be cached only after it has been requested 1 time.
  • Performance Impact: For 1, it means content is cached on the very first request. This maximizes caching benefits immediately. If you set it higher (e.g., proxy_cache_min_uses 2;), an item would only be cached after being requested twice, which might be useful if you only want to cache truly popular items to save disk space, but it delays the caching benefit.
  • Suggestion: For most websites, 1 is good, as it provides immediate caching benefits.

• proxy_cache_revalidate on;

  • Explanation: When a cached item becomes stale, Nginx will send a conditional request to the backend (using If-Modified-Since and If-None-Match headers). If the content hasn't changed, the backend can respond with a 304 Not Modified status, telling Nginx that its cached version is still valid, thus avoiding sending the full content again.
  • Performance Impact: Reduces bandwidth usage and backend CPU/memory by avoiding full content transfers when content hasn't changed. This is very efficient for refreshing stale content.
  • Suggestion: Keep on. This is a significant optimization.

• proxy_cache_use_stale error timeout updating http_500 http_502 http_503 http_504;

  • Explanation: This directive is a powerful feature for maintaining high availability. If Nginx tries to revalidate a cached item or fetch a new one from the backend, and the backend returns any of the specified errors (error, timeout, updating, http_500, http_502, http_503, http_504), Nginx will serve the stale (expired) content from its cache instead of returning an error to the client.
    • error: General proxying errors.
    • timeout: Backend connection or read timeout.
    • updating: Nginx is currently updating the cache for this item from the backend.
    • http_500, http_502, http_503, http_504: Specific HTTP error codes from the backend.
  • Performance Impact (Availability & User Experience): This significantly improves user experience during backend outages or temporary slowdowns. Users will still see content (even if slightly outdated) instead of an error page, greatly improving the perceived uptime and reliability of your service. It's a form of graceful degradation.
  • Suggestion: Keep this as is. It's an excellent resilience feature.

• add_header X-Cache-Status $upstream_cache_status;

  • Explanation: This adds a custom HTTP header to the response, indicating whether the content was served from the cache (HIT, MISS, EXPIRED, STALE, etc.). $upstream_cache_status is a built-in Nginx variable.
  • Performance Impact: Has a negligible performance impact.
  • Suggestion: This is purely for debugging and monitoring. It's incredibly useful during development and initial deployment to verify that your caching is working as expected. You can remove it in production if you don't need this information directly in the response headers.

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Overall Impact on Nginx Performance (CPU and Memory)

This location block, especially the caching directives, significantly offloads your backend application and improves performance:

• CPU:
  • Reduced Backend CPU: The biggest win is the massive reduction in CPU cycles on your backend application, as Nginx serves cached content without even touching it.
  • Nginx CPU: Nginx will use some CPU for cache lookups, file serving (especially with sendfile), and background cache management. However, this is typically much less than the CPU your application would use to generate the content.
• Memory:
  • Reduced Backend Memory: Your backend application will use less memory as it processes fewer requests.
  • Nginx Memory: Nginx will use memory for the keys_zone (already accounted for) and for buffering requests/responses. The proxy_cache_valid and proxy_cache_use_stale settings don't directly consume more memory but dictate what gets stored in the disk cache (which has its own max_size limit).

This is a very well-configured proxy and cache setup. It strikes a good balance between performance, content freshness, and resilience.

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Nginx Gzip Compression Settings

Let's break down your Nginx Gzip compression settings. These directives are vital for optimizing your website's performance by reducing the size of text-based responses sent to browsers, leading to faster load times and lower bandwidth consumption.

1. gzip on;

• Explanation: This is the master switch that enables Gzip compression in Nginx. If this is off, all other gzip_ directives related to compression won't have any effect.
• Performance Impact: When enabled, Nginx will compress eligible files (based on gzip_types) before sending them to the client. This significantly reduces the size of data transmitted over the network.
  • CPU: Compression consumes CPU cycles on the Nginx server.
  • Bandwidth: Drastically reduces the amount of data transferred, which is a major benefit, especially for users on slower connections or with limited data plans (like mobile users).
  • Latency: Faster downloads lead to lower perceived latency and quicker page load times for users in Cyberjaya and beyond.
• Suggestion: Keep on. It's a fundamental performance optimization.

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2. gzip_vary on;

• Explanation: This directive tells Nginx to add a Vary: Accept-Encoding header to responses that have been compressed. This header instructs proxy servers (like CDNs or ISP caches) and browsers to cache two separate versions of the resource: one compressed and one uncompressed. This is crucial because not all clients support Gzip compression.
• Performance Impact:
  • Correct Caching: Prevents proxies from serving a compressed version to a client that doesn't support Gzip, or an uncompressed version to a client that expects Gzip. This ensures the correct content is delivered to the right client.
  • Proxy Efficiency: Helps intermediate caches work more effectively, serving the appropriate version to various clients, which further speeds up delivery.
• Suggestion: Keep on. It's best practice for efficient caching and compatibility.

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3. gzip_proxied any;

• Explanation: This directive controls whether Nginx should compress responses for requests that originated from a proxy server.
  • any: Nginx will compress responses for all proxied requests, regardless of the request's headers (like Via, X-Forwarded-For, etc.).
• Performance Impact:
  • Comprehensive Compression: Ensures that compression benefits apply even when Nginx is behind another proxy (e.g., a load balancer or another CDN layer), as is common in complex infrastructures.
  • Reduced Traffic Between Proxies: If Nginx is serving compressed content to an upstream proxy, it reduces the data transferred between Nginx and that proxy, saving bandwidth and improving speed within your infrastructure.
• Suggestion: Keep any. It maximizes the benefits of Gzip compression across your entire delivery chain.

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4. gzip_comp_level 6;

• Explanation: This sets the Gzip compression level. The levels range from 1 (fastest compression, least reduction in size) to 9 (slowest compression, greatest reduction in size).
  • 6: This is a good balance between compression ratio and CPU usage. It offers a decent size reduction without placing an excessive burden on the server's CPU.
• Performance Impact:
  • CPU: Higher compression levels (e.g., 7-9) consume more CPU to compress the data, but might yield slightly smaller file sizes. Lower levels (e.g., 1-3) use less CPU but result in larger files.
  • Bandwidth: A higher compression level means smaller files, reducing bandwidth usage.
  • Latency: The trade-off is between the CPU time spent on compression and the time saved by downloading a smaller file. For most web content, level 6 often represents the "sweet spot." Beyond level 6, the gains in compression ratio typically diminish, while CPU usage continues to rise.
• Suggestion: 6 is an excellent choice. You could experiment with 5 if you notice high CPU usage during compression, or 7 if you prioritize minimal file size over a slight increase in CPU. For most dynamic web content, the difference in file size between 6 and 9 is often negligible for the increased CPU cost.

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5. gzip_types text/plain text/css text/xml application/json application/javascript application/rss+xml application/atom+xml image/svg+xml;

• Explanation: This directive specifies the MIME types of responses that Nginx should compress. Only responses with these Content-Type headers will be Gzipped.
• Performance Impact:
  • Targeted Compression: Ensures that only compressible content (text-based) is compressed. Binary files like JPEGs, PNGs, MP4s, etc., are usually already compressed by their native formats, and trying to Gzip them would be a waste of CPU cycles (they'd get very little, if any, additional compression, and might even increase in size in rare cases).
  • Efficiency: Reduces unnecessary CPU consumption by not attempting to compress already-compressed or incompressible data.
• Suggestion:
  • Your list is comprehensive and covers the most common compressible web assets.
  • You might consider adding application/x-javascript if you have older JavaScript files that use that MIME type, though application/javascript is standard now.
  • Also common to add font/ttf font/opentype application/x-font-woff application/font-woff2 if you're serving fonts directly and they're not already highly compressed.
  • image/svg+xml is correctly included, as SVG files are XML-based text files and compress very well.

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Overall Impact on Nginx Performance (CPU and Memory)

• CPU: Gzip compression directly consumes CPU resources. The gzip_comp_level plays the biggest role here. However, the CPU saved by faster network transfers and reduced bandwidth often outweighs the CPU cost of compression.
• Memory: Nginx uses a small amount of memory for buffering during the compression process. This is generally not a major concern unless you're serving extremely large, compressible files to a massive number of concurrent users.
• Bandwidth: This is where Gzip shines. It significantly reduces bandwidth usage, which can save on hosting costs and provide a much better experience for users, especially on metered or slower connections.

Your Gzip configuration is well-optimized. It's a standard and effective setup that balances CPU usage with substantial bandwidth and latency improvements, making your site load faster for visitors.

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Nginx Security Headers Explained

You've included a comprehensive set of security headers in your Nginx configuration, which is fantastic! These headers are critical for protecting your website and its users from various web vulnerabilities. They act as instructions to modern web browsers, telling them how to behave when interacting with your site.

Let's break down each one:

1. add_header X-XSS-Protection "1; mode=block" always;

• Explanation: This header enables the XSS (Cross-Site Scripting) filter built into many modern web browsers.
  • 1: Enables the filter.
  • mode=block: If an XSS attack is detected, the browser will prevent rendering of the entire page instead of attempting to sanitize it. This is generally safer.
• Security Benefit: Helps mitigate reflected XSS attacks by instructing the browser to activate its built-in XSS protection.
• Performance Impact: Negligible. The browser handles the XSS filtering, not Nginx.
• Suggestion: Keep this header. It provides a useful layer of defense, especially for older browsers or as a fallback.

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2. add_header X-Content-Type-Options "nosniff" always;

• Explanation: This header prevents browsers from "sniffing" the MIME type of a response. Without it, browsers might try to guess the content type of a file (e.g., interpret a .txt file as an executable script) if the Content-Type header is missing or generic.
• Security Benefit: Prevents MIME-sniffing attacks. This is crucial for preventing browsers from executing malicious code disguised as other file types (like an image). For example, it stops a browser from trying to execute a .txt file as JavaScript.
• Performance Impact: Negligible.
• Suggestion: Keep this header. It's a fundamental security hardening measure.

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3. add_header Referrer-Policy "no-referrer-when-downgrade" always;

• Explanation: This header controls how much referrer information (the URL of the previous page) is sent to other sites when a user clicks a link from your site.
  • no-referrer-when-downgrade: The browser sends the full referrer URL for requests within your site or to other HTTPS sites. However, no referrer is sent when navigating from an HTTPS site (your site) to an insecure HTTP site.
• Security/Privacy Benefit: Balances privacy and functionality. It protects user privacy by not leaking sensitive URLs to insecure destinations while still providing useful referrer information for secure analytics and tracking.
• Performance Impact: Negligible.
• Suggestion: This is a good, balanced policy. Many prefer more restrictive policies like same-origin or no-referrer for maximum privacy, but no-referrer-when-downgrade is a widely adopted secure default.

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4. add_header Content-Security-Policy "default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline'; frame-ancestors 'self';" always;

• Explanation: This is one of the most powerful and complex security headers. Content Security Policy (CSP) helps prevent various types of injection attacks, including XSS. It works by whitelisting the sources of content (scripts, stylesheets, images, fonts, etc.) that the browser is allowed to load and execute for a given page.
  • default-src 'self' http: https: ws: wss: data: blob: 'unsafe-inline';: This is a very broad default policy.
    • 'self': Allows content only from your own domain.
    • http: https: ws: wss: data: blob:: These allow content over various protocols, including WebSocket connections (ws: and wss:), and inline data URIs (data:, blob:).
    • 'unsafe-inline': This is a significant security exception. It allows inline JavaScript and CSS. While it makes CSP easier to implement, it largely negates one of CSP's primary XSS protections.
  • frame-ancestors 'self';: Restricts which domains can embed your content in an <iframe> or <frame>. 'self' means only pages from your own domain can frame your content, preventing clickjacking.
• Security Benefit: When correctly implemented (without unsafe-inline), CSP drastically reduces the attack surface for XSS, data injection, and clickjacking attacks.
• Performance Impact: Negligible for Nginx. It's an instruction to the browser.
• Suggestions:
  • Crucial Improvement: The most important suggestion here is to remove 'unsafe-inline' from your Content-Security-Policy and instead use SHA-256 hashes or nonces for inline scripts/styles. 'unsafe-inline' effectively renders a large part of CSP's XSS protection useless. This often requires changes to your application to generate these hashes or nonces.
  • Be Specific: Instead of a broad default-src, use more specific directives like script-src, style-src, img-src, font-src, connect-src, etc., to tightly control each type of resource.
  • Monitor First: For complex applications, start with Content-Security-Policy-Report-Only (which only reports violations to a specified URI, rather than blocking them) to identify issues before enforcing a strict policy.
  • Example (more secure, but requires app changes):

    add_header Content-Security-Policy "default-src 'self'; script-src 'self' https://cdn.example.com; style-src 'self' 'sha256-YOURHASHHERE'; img-src 'self' data:; connect-src 'self' ws: wss:; frame-ancestors 'self';" always;

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5. add_header Permissions-Policy "interest-cohort=()" always;

• Explanation: This header (formerly Feature-Policy) allows you to explicitly enable or disable various browser features and APIs for your own origin and for third-party content embedded on your site.
  • interest-cohort=(): Specifically disables the "Federated Learning of Cohorts" (FLoC) API. FLoC was Google's proposed privacy-preserving alternative to third-party cookies for interest-based advertising, but it has faced significant privacy concerns.
• Security/Privacy Benefit: Gives you control over browser features that might have privacy implications or could be exploited. Disabling interest-cohort explicitly opts your site out of FLoC tracking.
• Performance Impact: Negligible.
• Suggestion: This is a good and relevant privacy-focused setting for current web standards. Keep it.

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6. add_header Strict-Transport-Security "max-age=31536000; includeSubDomains; preload" always;

• Explanation: This is the HSTS (HTTP Strict Transport Security) header, a critical security measure.
  • max-age=31536000: Instructs the browser to only connect to your domain over HTTPS for the next 31,536,000 seconds (1 year). Even if a user tries to access http://yourdomain.com, the browser will automatically rewrite it to https://yourdomain.com without even sending a request to the insecure HTTP port.
  • includeSubDomains: Applies the HSTS policy to all subdomains (e.g., blog.linuxmalaysia.com, shop.linuxmalaysia.com).
  • preload: This flag is a signal that your domain is eligible for inclusion in browser's HSTS preload lists. Submitting your domain to the [HSTS Preload List](https://hstspreload.org/) ensures that browsers never try to connect to your site over HTTP, even on the very first visit.
• Security Benefit:
  • Prevents SSL Stripping: Protects against "SSL stripping" attacks where an attacker downgrades an HTTPS connection to HTTP.
  • Eliminates Mixed Content Issues: Reduces the likelihood of mixed content warnings by forcing HTTPS.
  • Protects First Visit: The preload flag is key for the "trust on first use" problem, where the very first connection to a site could be vulnerable.
• Performance Impact:
  • Minor initial overhead: The browser might need to parse this header once.
  • Faster Subsequent Connections: By forcing HTTPS and removing the need for 301 redirects from HTTP to HTTPS, it actually speeds up subsequent connections.
• Important Considerations:
  • HTTPS Must Be Rock Solid: Do not enable HSTS (especially preload) unless your entire domain, including all subdomains, is exclusively and permanently served over HTTPS. If any part of your site ever serves over HTTP, users might be locked out.
  • Difficult to Revert: Once your domain is on the HSTS preload list, it's very difficult to remove.

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Overall Security and Performance of Headers:

Your security headers are a strong foundation! They demonstrate a clear commitment to user security.

• The X-XSS-Protection, X-Content-Type-Options, and Referrer-Policy are good, standard security measures.
• Permissions-Policy is a modern privacy enhancement.
• HSTS (Strict-Transport-Security) is excellent and highly recommended.
• Content Security Policy (Content-Security-Policy) is the most powerful but also the most nuanced. The unsafe-inline directive is a significant weakness in your current CSP that you should prioritize addressing for maximum protection.

Applying these headers doesn't add much, if any, overhead to Nginx's processing. Their benefit lies in guiding browser behavior for a more secure user experience, which indirectly contributes to performance by preventing security incidents that could otherwise degrade service.

Do you have plans to tighten up your Content Security Policy, or are there any other security aspects you're considering for your Nginx setup in Cyberjaya?

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Nginx Proxy Timeout Settings Explained

You're looking at the proxy timeout directives, which are critical for controlling how long Nginx waits for your backend application to respond. These settings directly impact the responsiveness and reliability of your service, especially when your backend is under load or experiencing issues.

All of these timeouts are set to 60s (60 seconds), which is a common value for general web applications. Let's break down what each one means:

1. proxy_connect_timeout 60s;

• Explanation: This sets the maximum time Nginx will wait to establish a connection with your proxied backend server (http://127.0.0.1:3000). This includes the time needed for DNS resolution (if using a hostname), establishing the TCP handshake, and performing the SSL/TLS handshake (if your backend uses HTTPS).
• Performance Impact:
  • Responsiveness: If your backend server is slow to respond to new connection requests (e.g., due to high load, network issues, or a crash), Nginx will wait up to 60 seconds. If the connection isn't established within this time, Nginx will return a 502 Bad Gateway error to the client.
  • Backend Health: A higher timeout gives a struggling backend more time to recover and accept new connections. A lower timeout makes Nginx fail faster, potentially preventing requests from piling up on a dead backend.
• Suggestions:
  • 60s is a generous timeout. For most well-behaved local backends, connection establishment should be near-instantaneous.
  • If your backend is highly performant and stable, you could consider lowering this to 5s or 10s to make Nginx fail faster when the backend is truly unreachable, giving immediate feedback to the client or allowing other mechanisms (like retries) to kick in sooner.
  • If your backend starts slowly or occasionally takes time to come online (less common for a Node.js app on 127.0.0.1), a higher value like 60s might be necessary.

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2. proxy_send_timeout 60s;

• Explanation: This sets the maximum time Nginx will wait for your backend server to send a response after it has processed a request. Specifically, it's the timeout for sending a request to the proxied server. It applies between two successive write operations, not for the entire response. If the backend doesn't send anything for 60 seconds (no data, no headers), Nginx will close the connection.
• Performance Impact:
  • Backend Stuck: Protects Nginx from a backend that accepts a connection but then gets "stuck" and doesn't write any data back to Nginx.
  • Resource Management: Prevents Nginx from holding open connections indefinitely to a non-responsive backend, freeing up Nginx's resources.
• Suggestions:
  • 60s is a standard and generally safe value.
  • For applications that involve very long-running writes from the backend (e.g., large file uploads from the backend to Nginx, or streaming responses), you might need to increase this. However, for typical web requests, 60s is usually sufficient.

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3. proxy_read_timeout 60s;

• Explanation: This sets the maximum time Nginx will wait for your backend server to send data in response to a request. This applies between two successive read operations. If Nginx doesn't receive any data from the backend for 60 seconds, it will close the connection. This is typically the most important timeout for user experience.
• Performance Impact:
  • User Experience: Directly impacts how long a user waits for a response. If your backend takes longer than 60 seconds to start sending the response (or send another chunk of data), the user will see a timeout error.
  • Backend Processing Time: If your backend application has computationally intensive tasks or database queries that might exceed 60 seconds to complete, you'll need to increase this timeout.
  • Resource Management: Prevents Nginx from tying up resources waiting for a backend that is too slow or unresponsive.
• Suggestions:
  • 60s is a common default, suitable for most web applications.
  • Adjust based on application needs: If you have long-running API calls, complex reports, or file generation processes in your backend that might genuinely take more than 60 seconds, you must increase this timeout (e.g., 120s, 300s, or even more).
  • For interactive or fast-response APIs, you could consider lowering it (e.g., 30s) to ensure quicker failure feedback.

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Overall Impact on Nginx Performance (CPU and Memory)

• CPU/Memory: These timeouts don't directly consume CPU or memory during normal operation. Their impact comes when timeouts occur. If a timeout happens, Nginx might use a small amount of CPU to log the error and terminate the connection. Having appropriate timeouts prevents Nginx from holding open connections indefinitely to a problematic backend, which could otherwise tie up Nginx's worker processes and consume memory unnecessarily.
• Reliability: By setting these timeouts, you define the acceptable window for your backend to perform. If it exceeds these, Nginx intervenes, preventing users from waiting indefinitely and allowing Nginx to free up resources.

Your current timeout settings are a sensible starting point for many web applications. The key is to monitor your Nginx error logs for 502 Bad Gateway errors or "upstream timed out" messages, as these would indicate that your backend is hitting these limits, and you might need to adjust them based on your application's specific behavior.

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Nginx Logging Configuration Explained

You've provided your Nginx logging configuration, which is essential for monitoring the health, activity, and potential issues on your server. These settings tell Nginx where to record information and how verbose those logs should be.

Let's break down each line:

1. access_log /var/log/nginx/access.log combined buffer=512k flush=1m;

This directive configures the access log, which records every request Nginx handles.

• /var/log/nginx/access.log: This is the path to the file where Nginx will write access log entries. It's standard practice to keep Nginx logs in the /var/log/nginx/ directory.
  • Performance Impact: Logging to disk involves disk I/O. For very high-traffic sites, excessive logging (or logging to slow disks) can become a bottleneck. However, the buffering parameters you've set help mitigate this.
  • Suggestion: Ensure the www-data user has write permissions to /var/log/nginx/.
• combined: This specifies the log format to be used. The combined format is a standard Apache-like format that includes common information like:
  • Remote IP address
  • Request time
  • HTTP method and URI
  • HTTP status code
  • Response body size
  • Referer header
  • User-Agent header
  • Performance Impact: The chosen format slightly affects the amount of data written, but combined is a good balance between detail and file size.
  • Suggestion: combined is excellent for most purposes. If you ever need more detailed information (e.g., specific headers, upstream response times), you can define a custom log_format.
• buffer=512k: This enables buffering of log entries in memory. Nginx will collect log entries up to 512 kilobytes in size before writing them to disk.
  • Performance Impact (CPU & Disk I/O): This is a significant optimization for busy servers. Instead of writing each log entry individually (which causes many small disk I/O operations and context switches), Nginx writes larger chunks less frequently. This reduces disk I/O, saves CPU cycles, and improves overall throughput.
  • Memory Impact: Directly consumes 512KB of RAM for the buffer. This is a very small and acceptable overhead for the performance gain.
  • Suggestion: 512k is a good size. For extremely high-traffic sites, you might consider increasing this to 1m or 2m, but it's often not necessary.
• flush=1m: This directive works with buffer. It sets a maximum time limit for how long buffered log entries can remain in memory before being written to disk, even if the buffer isn't full. Here, it means that even if the 512k buffer isn't filled, Nginx will write its contents to disk every 1 minute.
  • Performance Impact: Ensures that log data isn't held indefinitely in memory, which is important for real-time monitoring and analysis, as well as data persistence in case of an unexpected crash.
  • Suggestion: 1m is a standard and reasonable flush interval.

2. error_log /var/log/nginx/error.log warn;

This directive configures the error log, which records messages about Nginx's own operations, warnings, and errors.

• /var/log/nginx/error.log: This is the path to the file where Nginx will write error log entries.
  • Performance Impact: Less frequent writing than access logs, as it only records problems. The performance impact is minimal.
  • Suggestion: As with access logs, ensure correct write permissions.
• warn: This sets the minimum severity level of messages that will be written to the error log. Nginx logs messages at different levels: debug, info, notice, warn, error, crit, alert, and emerg (from most verbose to least verbose).
  • Performance Impact: A lower (more verbose) log level (e.g., info or debug) will write many more messages, increasing disk I/O and potentially consuming more CPU. A higher (less verbose) level (e.g., error or crit) will log fewer messages.
  • warn level: Means Nginx will log messages with warn severity or higher (i.e., warn, error, crit, alert, emerg). This is a good balance:
    • It captures important warnings (e.g., keys_zone full, deprecated directives, OCSP stapling issues) that you should be aware of.
    • It avoids flooding the log with info or debug messages, which are usually only needed during active troubleshooting.
  • Suggestion: warn is an excellent choice for a production environment. For active debugging, you might temporarily switch to info or even debug (if Nginx was compiled with debugging enabled), but always revert to warn or higher for normal operation.

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Overall Impact on Nginx Performance (CPU and Memory)

• CPU: Logging consumes some CPU for formatting log entries and performing disk I/O. The buffer setting for access logs significantly reduces this overhead.
• Memory: A small amount of memory is used for the access_log buffer (512k).
• Disk I/O: Both logs write to disk. Efficient logging practices (like buffering) minimize the impact on disk I/O.
• Visibility & Debugging: While not a direct performance gain in terms of request processing speed, well-configured logging is paramount for identifying performance bottlenecks, security incidents, and operational issues. Without proper logs, troubleshooting becomes significantly harder, leading to longer downtimes or unaddressed problems that do affect performance.

Your logging configuration is very solid, balancing verbosity with performance by utilizing buffering for access logs and a sensible warning level for error logs.

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HTTP to HTTPS Redirect Configuration

This server block is solely dedicated to handling HTTP requests and redirecting them to your secure HTTPS site. This is a crucial security and SEO best practice.

Let's break down each part:

• listen 80 reuseport;

  • Explanation: This tells Nginx to listen for incoming connections on port 80 (the standard port for unencrypted HTTP traffic) for IPv4 addresses. The reuseport option (available in Nginx 1.9.1+ on Linux) allows multiple worker processes to listen on the same port, which can improve performance by distributing incoming connections more evenly across workers.
  • Performance Impact: Listening on port 80 is necessary to capture all HTTP requests. reuseport can offer minor performance benefits on high-concurrency systems by reducing lock contention when accepting new connections.

• listen [::]:80 reuseport;

  • Explanation: This is similar to the above, but it tells Nginx to listen on port 80 for IPv6 addresses. This ensures that users connecting via IPv6 are also correctly redirected.
  • Performance Impact: Same as the IPv4 listen directive.

• server_name linuxmalaysia.com;

  • Explanation: This specifies that this server block should handle requests for the domain linuxmalaysia.com. If you have other domains or subdomains, you'd need separate server_name entries or additional server blocks for them.
  • Performance Impact: Nginx efficiently matches server_name directives to direct traffic to the correct block.

• access_log /var/log/nginx/access.log combined buffer=512k flush=1m;

  • Explanation: This configures access logging for this specific HTTP redirect block. It uses the combined format, buffers logs in memory (up to 512KB), and flushes them to disk every 1 minute. This is the same logging configuration as your main HTTPS block.
  • Performance Impact: Logging has a small overhead, but the buffering helps minimize its impact on disk I/O and CPU, even for redirect-only requests. It's useful to log redirects to ensure they're happening as expected.

• error_log /var/log/nginx/error.log warn;

  • Explanation: This configures error logging for this block, setting the minimum severity level to warn.
  • Performance Impact: Minimal, as errors are less frequent. It helps in diagnosing any issues with the redirection process.

• return 301 https://linuxmalaysia.com$request_uri;

  • Explanation: This is the core of the redirection.
    • return 301: Nginx will send an HTTP 301 Moved Permanently status code to the client. This is crucial for SEO, as it tells search engines that the content has permanently moved to the HTTPS version, transferring any SEO "link juice" to the new URL.
    • https://linuxmalaysia.com: This is the target protocol and domain.
    • $request_uri: This Nginx variable preserves the original path and query string from the incoming HTTP request. So, if a user types http://linuxmalaysia.com/about?lang=en, they will be redirected to https://linuxmalaysia.com/about?lang=en.
  • Performance Impact: This is an incredibly efficient way to handle redirects in Nginx. Nginx doesn't need to process the request further or hit your backend application; it simply sends the redirect header directly. This minimizes CPU and memory usage for HTTP requests.

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Overall Performance and Importance

This entire server block is extremely important for:

• Security: Forcing all traffic to HTTPS is fundamental for securing user data and ensuring privacy.
• SEO (Search Engine Optimization): Using a 301 redirect ensures that search engines correctly update their indexes and your site doesn't lose ranking due to duplicate content (HTTP vs. HTTPS).
• User Experience: While it adds a single extra HTTP round-trip for the initial redirect, it ensures users always land on the secure version of your site. Modern browsers (especially with HSTS preloading) often automatically upgrade HTTP requests to HTTPS, making this redirect transparent after the first visit.
• Efficiency: Nginx handles this redirect very efficiently, serving the redirect directly without involving your backend application.

This is a standard and highly recommended configuration for any website using HTTPS. You've implemented it correctly and efficiently.

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Nginx Proxy SSL Server Name Indication (SNI)

You're asking about the proxy_ssl_server_name directive. This setting is crucial when Nginx is proxying HTTPS requests to a backend server that hosts multiple SSL certificates on the same IP address.

Here's a breakdown:

What is SNI (Server Name Indication)?

Traditionally, for a server to host multiple secure websites (each with its own SSL certificate) on a single IP address, it would need a separate IP address for each. This is because the SSL handshake happens before the HTTP Host header (which indicates the desired website) is sent. So, the server wouldn't know which certificate to present.

Server Name Indication (SNI) is an extension to the TLS protocol that solves this problem. With SNI, the client (e.g., a web browser) includes the hostname it's trying to connect to within the initial TLS handshake. This allows the server to present the correct SSL certificate, even if it's hosting many websites on the same IP address.

proxy_ssl_server_name on;

• Explanation: When proxy_ssl_server_name is set to on, Nginx will pass the hostname from the client's original request (the Host header Nginx received from the client) to your backend server during the SSL/TLS handshake.
• How it works:
  1. A client connects to Nginx over HTTPS (e.g., https://linuxmalaysia.com).
  2. Nginx receives the request, including the Host header (linuxmalaysia.com).
  3. Nginx acts as a client to your backend server (http://127.0.0.1:3000).
  4. If your backend also uses HTTPS (e.g., https://127.0.0.1:3000), Nginx will include the original hostname (linuxmalaysia.com) in its TLS handshake with the backend.
  5. This allows your backend server to select and present the correct SSL certificate for linuxmalaysia.com (if it hosts multiple SSL-secured sites) to Nginx.
• When it's important: This setting is essential if:
  • Your Nginx instance is proxying to an HTTPS backend (meaning proxy_pass is to https://...).
  • And that HTTPS backend hosts multiple domains/certificates on the same IP address. Without proxy_ssl_server_name on;, the backend might present the wrong certificate, leading to SSL errors between Nginx and the backend.

Performance Impact

• Negligible on CPU/Memory: This setting has a minimal to negligible impact on Nginx's CPU or memory usage. It's primarily about ensuring the correct SSL handshake happens between Nginx and the backend.
• Crucial for Correctness: Its main "performance" benefit is that it enables your SSL-secured backend to function correctly in a multi-domain setup. Without it, you'd encounter SSL handshake failures or certificate mismatches between Nginx and your backend, leading to client errors and service outages.

Suggestions

• Keep it on if your backend uses HTTPS and hosts multiple domains: If your proxy_pass URL is https://127.0.0.1:3000 (instead of http://127.0.0.1:3000 as in your current config) AND your backend application serves different domains over HTTPS from a single IP, then proxy_ssl_server_name on; is absolutely necessary.
• It's currently redundant in your provided config: In your current configuration, proxy_pass is set to http://127.0.0.1:3000;. This means Nginx is connecting to your backend using plain HTTP, not HTTPS. In this scenario, proxy_ssl_server_name on; has no effect because there's no SSL handshake happening between Nginx and the backend.

Conclusion: While proxy_ssl_server_name on; is a best practice for Nginx when proxying to HTTPS backends, it's currently a no-op given your proxy_pass http://127.0.0.1:3000; directive. If you ever switch your backend to serve over HTTPS, this line will become highly relevant and important.

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Nginx Security and .well-known File Handling

You're configuring some important aspects of how Nginx handles specific files and directories, particularly those starting with a dot (.) and the security.txt file. These settings are crucial for both security and compliance with modern web standards.

Let's break down each of these location blocks:

1. location ~ /\.(?!well-known) { deny all; }

• Explanation: This location block uses a regular expression to match requests for files or directories that start with a dot (.) but are NOT within the .well-known directory.
  • ~: Indicates a regular expression match (case-sensitive).
  • /\.: Matches a literal dot at the beginning of a path segment (like .htaccess, .env, .git).
  • (?!well-known): This is a negative lookahead assertion. It means "match a dot, but only if it's NOT followed by 'well-known'".
  • deny all;: If a request matches this pattern, Nginx will immediately deny access, returning a 403 Forbidden error.
• Security Benefit: This is a critical security measure. Many sensitive files used by applications or version control systems (like .env for environment variables, .git for Git repositories, .htaccess for Apache configurations) start with a dot. Serving these files publicly could expose sensitive information, leading to severe security vulnerabilities. This directive ensures they are never served by Nginx.
• Performance Impact: Negligible. It's a quick check and deny, which is very efficient.
• Suggestion: Keep this as is. It's a fundamental security best practice.

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2. location /security.txt { return 301 /.well-known/security.txt; }

• Explanation: This location block handles requests for /security.txt. It issues a permanent redirect (301 Moved Permanently) to /.well-known/security.txt.
• Security Benefit: The security.txt file is a proposed standard for website security, allowing security researchers to easily find contact information for reporting vulnerabilities. The official standard dictates it should be placed under the /.well-known/ directory. This redirect ensures that if someone (human or automated scanner) looks for the file at the old or common root location, they are guided to the correct, standardized location.
• Performance Impact: Minor. It's a single HTTP redirect. The 301 status code tells browsers and search engines to cache the redirect, so subsequent requests go directly to the new location.
• Suggestion: Keep this redirect. It helps with compliance and discoverability for security researchers.

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3. location = /.well-known/security.txt { alias ~/security.txt; }

• Explanation: This location block specifically handles requests for /.well-known/security.txt.
  • =: Denotes an exact match. This means this block will only process requests that precisely match /.well-known/security.txt.
  • alias ~/security.txt;: This is an important part.
    • alias: Specifies a different base path for the file than the root directive of the server block.
    • ~/security.txt: The tilde ~ symbol usually refers to the user's home directory. If Nginx is running as www-data, ~ would typically resolve to /var/www/. This implies your security.txt file is expected to be located at /var/www/security.txt (or /home/www-data/security.txt if that's the user's home).
• Security Benefit: Correctly serves the security.txt file from a designated location, fulfilling the proposed standard for vulnerability reporting.
• Performance Impact: Negligible. Serving a small static file is very efficient for Nginx.
• Important Consideration / Suggestion:
  • File Location: You need to ensure that the security.txt file actually exists at the path specified by alias ~/security.txt. Based on your earlier root /var/www/linuxmalaysia.com/public; setting, a more common and explicit path for this would be alias /var/www/linuxmalaysia.com/security.txt; or even alias /etc/nginx/security.txt; if you prefer to keep it separate from your website's public directory.
  • User Permissions: The Nginx user (www-data) must have read permissions for the security.txt file at the alias path.

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Overall Summary of these Directives:

These location blocks demonstrate good practices for managing specific file access and adhering to web standards:

• The deny all for dotfiles is a crucial security hardened default.
• The security.txt redirects and serving ensure you comply with a valuable security and transparency standard.

Your configuration for these elements is generally solid. The main point to double-check is the exact path of your security.txt file to ensure it aligns with the alias directive's interpretation of ~.

Is there anything else you'd like to understand about your Nginx setup, or any other parts of the configuration you'd like to review?

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Nginx Request Method Restriction

You're using an if directive to restrict the HTTP methods that Nginx will allow for requests. This is a security measure that can help protect your backend application from unexpected or potentially malicious requests using methods your application isn't designed to handle.

Let's break down this configuration:

• if ($request_method !~ ^(GET|POST|PUT|HEAD|CONNECT)$) { ... }

  • if directive: This is a conditional statement in Nginx. While generally discouraged for complex logic (due to some known issues and performance characteristics with complex if blocks), for simple checks like this, it's often used.
  • $request_method: This is a built-in Nginx variable that holds the HTTP method of the current request (e.g., GET, POST, DELETE, OPTIONS).
  • !~: This is the "does not match" operator for regular expressions (case-sensitive).
  • ^(GET|POST|PUT|HEAD|CONNECT)$: This is the regular expression pattern.
    • ^: Matches the beginning of the string.
    • $: Matches the end of the string.
    • (GET|POST|PUT|HEAD|CONNECT): This is a group that matches any of the specified HTTP methods.
      • GET: Used to retrieve data.
      • POST: Used to submit data to be processed.
      • PUT: Used to create or replace a resource.
      • HEAD: Similar to GET, but requests only the headers, not the body.
      • CONNECT: Used to establish a tunnel to the server, primarily for proxies.
  • In summary: The if condition evaluates to true if the $request_method is not one of GET, POST, PUT, HEAD, or CONNECT.

• return '405';

  • Explanation: If the if condition is true (i.e., the request method is not one of the allowed ones), Nginx will immediately return an HTTP 405 Method Not Allowed status code to the client. This tells the client that the method used is not supported for the requested resource.

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Security Benefit

• Method Filtering: This helps ensure that your backend application only receives requests using the HTTP methods it's designed to process.
• Reduced Attack Surface: By explicitly denying unexpected methods, you can reduce the attack surface. For example, if your application doesn't implement DELETE or OPTIONS (which it likely should for REST APIs, but this is a generic setup), blocking them at the Nginx level can prevent potential vulnerabilities if these methods were somehow mishandled by your backend.
• Compliance: Can help in scenarios where strict adherence to allowed methods is required.

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Performance Impact

• Minimal CPU/Memory: The impact on Nginx's CPU and memory is very minimal. Regular expression matching for a short string is a highly optimized operation. If a method is denied, Nginx returns the error immediately, consuming very few resources for that request.
• Efficiency: For disallowed methods, Nginx efficiently terminates the request at the edge, preventing it from ever reaching your backend application. This saves CPU and resources on your backend that would otherwise be spent processing and rejecting an invalid request.

---

Suggestions

• Consider your application's needs: Before implementing method restrictions, ensure that your backend application genuinely does not use any other HTTP methods.
  • For a typical RESTful API, you'd usually also allow DELETE and PATCH.
  • OPTIONS is commonly used for CORS (Cross-Origin Resource Sharing) preflight requests. If you have a frontend application on a different domain interacting with your backend, denying OPTIONS will break CORS.
• Placement: This if block is typically placed within a server block or a specific location block. Placing it in the http block (which seems to be the case here, given the context of your previous snippets) applies it globally to all server blocks unless overridden. This is fine for a blanket restriction.
• Nginx if directive caution: While this specific use case is generally considered acceptable for if, it's worth noting that the if directive can sometimes lead to unexpected behavior when combined with other directives, especially in more complex scenarios. For method restriction specifically, it's usually safe.

In summary, this if block is a simple yet effective security measure to restrict HTTP methods, contributing to a more robust and secure Nginx setup. Just ensure the allowed methods align with your application's actual requirements.

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Nginx Configuration for favicon.ico and robots.txt

These two location blocks are dedicated to handling requests for favicon.ico and robots.txt. While seemingly minor, they help optimize your Nginx logs and prevent unnecessary logging noise, which can be beneficial for performance in very high-traffic scenarios.

Let's look at each:

1. location = /favicon.ico { log_not_found off; }

• Explanation: This block specifically targets requests for /favicon.ico.

  • location = /favicon.ico: The = sign ensures an exact match for this URI. Requests for favicon.ico (which is the small icon displayed in browser tabs) are very common.
  • log_not_found off;: This is the key part. It tells Nginx not to log 404 "file not found" errors to the error_log if favicon.ico isn't found.

• Performance Impact:

  • Reduced Log Noise: Favicons are often requested automatically by browsers, and if the file doesn't exist (or isn't found at that exact path), it would generate a 404 error entry in your error_log. Turning log_not_found off keeps your error logs cleaner and more focused on actual issues.
  • Minimal CPU/Disk I/O: For very high-traffic sites, preventing thousands of 404 error log entries can save a tiny amount of CPU and disk I/O, as Nginx doesn't have to write these messages. This is more about efficiency and clean logs than a major performance boost.

• Suggestion: Keep this setting. It's a standard and good practice for managing Nginx logs.

---

2. location = /robots.txt { log_not_found off; }

• Explanation: This block is identical in purpose to the favicon.ico one, but it applies to /robots.txt.

  • location = /robots.txt: Ensures an exact match for the robots.txt file, which search engine crawlers (like Googlebot) request to understand your site's crawling rules.
  • log_not_found off;: Prevents 404 errors for robots.txt from being logged if the file isn't found.

• Performance Impact:

  • Reduced Log Noise: Similar to favicon.ico, if robots.txt isn't present or found by Nginx, it would generate 404 entries. This directive keeps those out of your error logs.
  • Minimal CPU/Disk I/O: Again, this contributes to marginal savings in CPU and disk I/O by avoiding unnecessary log writes.

• Suggestion: Keep this setting. It's another standard and good practice for log management.

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Overall Summary

These directives don't directly enhance the speed of content delivery, but they are beneficial for the operational efficiency and clarity of your Nginx server. By explicitly turning off 404 logging for these commonly requested (and sometimes missing) files, you keep your error logs focused on more significant issues, making it easier to monitor and troubleshoot your server. This is especially useful for managing a web server like yours, which handles traffic in Cyberjaya, Selangor, Malaysia, and globally.

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That's a very common if block you've got there! While it serves a good purpose in restricting HTTP methods, the general consensus in the Nginx community is to avoid if statements when possible due to potential unexpected behavior in certain complex scenarios.

However, for simple method checks like this, it's often deemed acceptable. If you're running a basic web server with a standard application (like a blog or a simple API), your current setup is likely fine and provides good security benefits by explicitly allowing only the methods your application expects.

Here are a few suggestions based on your current configuration and common Nginx practices:

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1. Keep it as is (if your application strictly uses these methods)

If your application truly only relies on GET, POST, PUT, HEAD, and CONNECT methods, then your current if statement effectively limits unnecessary requests to your backend, providing a basic security layer.

• Pros: Simple, readable, and immediately understood. It effectively filters unwanted methods at the Nginx edge.
• Cons: Uses an if statement, which purists generally avoid, though its impact here is minimal.
• Use Case: Ideal for applications that definitely don't use methods like DELETE, PATCH, or OPTIONS (e.g., a static site served through Nginx, or an API that uses only the listed methods).

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2. Refine the Allowed Methods (if your application needs more)

Consider if your application requires other standard HTTP methods. For example, if you're building a RESTful API, you'll very likely need DELETE and PATCH. Additionally, OPTIONS is frequently used for CORS (Cross-Origin Resource Sharing) preflight requests. If you have a frontend JavaScript application hosted on a different domain from your API, it will send OPTIONS requests, and blocking them will break your frontend's ability to communicate with the API.

Suggestion: Add any methods your application legitimately uses. For a typical API, a more comprehensive list might look like this:

---
# Suggested Method Restriction
if ($request_method !~ ^(GET|POST|PUT|DELETE|PATCH|HEAD|OPTIONS|CONNECT)$) {
    return 405;
}

• Pros: Ensures your application functions correctly with all necessary HTTP verbs. Handles common CORS scenarios.
• Cons: Still uses an if statement.
• Use Case: Recommended for modern web applications, especially those with APIs and separate frontends.

---

3. Remove the Restriction (if you're unsure or your backend handles it)

If you're unsure which methods your backend uses or if your application server (e.g., Node.js, Python, PHP framework) is already robustly handling method validation, you could simply remove this if block.

• Pros: Simplifies your Nginx configuration. Defers method validation entirely to your application, which might be more appropriate if the application logic is complex.
• Cons: Less filtering at the Nginx edge; all method types will hit your backend, potentially exposing it to methods it doesn't handle.
• Use Case: When your application framework (like Express.js, Django REST Framework, Laravel) is explicitly designed to handle all HTTP methods and return appropriate 405 responses or specific logic for each, making Nginx's check redundant.

---

Which suggestion is best for you?

Given your setup with proxy_pass http://127.0.0.1:3000;, it sounds like you're running a backend application (likely Node.js, since 3000 is a common port).

1. If you're running a simple content-serving application or a blog without complex interactive features/APIs, then keeping your current list of methods is probably sufficient.
2. However, if your linuxmalaysia.com site includes APIs, user interactions, or forms that might update/delete data, or if you have a separate frontend that makes AJAX requests, then I'd strongly suggest you refine the allowed methods to include OPTIONS, DELETE, and PATCH (if your API uses them). This will prevent unexpected 405 errors and ensure full functionality.

Before making any changes, always test thoroughly to ensure your application behaves as expected with the chosen method restrictions!

User ulimit (for Nginx user):

Even with fs.file-max set, the user running Nginx (often nginx or www-data) needs a high nofile limit in /etc/security/limits.conf or a file in /etc/security/limits.d/.

nginx soft nofile 655360
nginx hard nofile 655360

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Let's break down the events block in your Nginx configuration. This block is crucial because it defines how Nginx handles connections and influences its scalability and performance, particularly concerning concurrent users.

events { ... }

The events block is a top-level configuration block in Nginx (alongside http, mail, stream, etc.). It contains directives that set global parameters for connection processing.

1. worker_connections 65536;

• Explanation: This directive specifies the maximum number of simultaneous connections that a single Nginx worker process can open.
  • Since Nginx typically runs multiple worker processes (controlled by worker_processes in the main configuration block, often set to auto or the number of CPU cores), the total maximum number of connections Nginx can handle concurrently is worker_connections * worker_processes.
  • For example, if you have 4 worker processes and worker_connections 65536;, Nginx can theoretically handle $4 \times 65536 = 262144$ simultaneous connections.
• Performance Impact (Scalability & Resource Usage):
  • High Concurrency: A high worker_connections value allows Nginx to handle a very large number of concurrent clients, which is essential for high-traffic websites.
  • Memory: Each connection consumes a small amount of memory. Setting this too high without sufficient RAM could lead to memory exhaustion.
  • CPU: While Nginx is very efficient, handling a vast number of connections will consume CPU cycles for processing requests.
  • File Descriptors: Each connection is a file descriptor. This setting must be lower than or equal to the operating system's per-process file descriptor limit.
• Suggestions:
  • 65536 is a very common and high value, indicating a server designed for high concurrency.
  • Practical Limit: While Nginx might be configured for 65,536 connections per worker, the actual practical limit is often determined by the server's CPU, memory, and network bandwidth.
  • Monitoring: Monitor your server's resource usage (CPU, RAM, open file descriptors) under load to ensure it can comfortably handle this many connections. If you consistently hit the limit, consider scaling up your hardware or optimizing other parts of your Nginx/application stack.

2. worker_rlimit_nofile 655360;

• Explanation: This directive sets the maximum number of open file descriptors (the RLIMIT_NOFILE limit) for Nginx's worker processes.
  • A file descriptor is used for every connection, every file being served, every log file, and so on.
  • The value 655360 (655,360) is ten times your worker_connections value.
• Performance Impact (Stability & Reliability):
  • Prevents "Too Many Open Files" Errors: If Nginx runs out of file descriptors, it cannot accept new connections or open files, leading to service disruption and "Too many open files" errors in your logs.
  • Must be High Enough: This value must be at least worker_connections. It's often recommended to set it higher (e.g., 1.5x to 2x worker_connections for general use, or even 10x as you have for very busy servers) to account for other file descriptors used by Nginx (e.g., log files, cache files, internal pipes, upstream connections).
  • Operating System Limit: This Nginx setting cannot exceed the operating system's system-wide file descriptor limit (fs.file-max) or the per-user/per-process ulimit -n setting. You often need to adjust these OS limits first.
• Suggestions:
  • 655360 is a very high and appropriate value for a server aiming for high concurrency.
  • Verify OS Limits: Before setting worker_rlimit_nofile this high, you must ensure your Linux system's ulimit -n for the Nginx user and fs.file-max kernel parameter are set to at least this value (or higher).
    • To check ulimit -n for the Nginx user (e.g., www-data):

      sudo su - www-data -c 'ulimit -n'

    • To check system-wide fs.file-max:

      cat /proc/sys/fs/file-max

    • To temporarily set ulimit -n for the current shell (e.g., for testing): ulimit -n 655360
    • To make it permanent, you'd typically edit /etc/security/limits.conf (for nofile for the www-data user) and /etc/sysctl.conf (for fs.file-max).

3. use epoll; (Example, commented out in your snippet)

• Explanation: This directive specifies the connection processing method Nginx will use.
  • epoll is the most efficient and scalable I/O event notification mechanism on Linux systems. It allows Nginx to efficiently monitor a large number of file descriptors for readiness events (e.g., a new connection, data arriving on an existing connection).
  • Other methods exist (kqueue for FreeBSD/macOS, select, poll), but epoll is the default and preferred method on Linux due to its superior performance for high concurrency.
• Performance Impact (CPU & Scalability):
  • Highly Efficient: epoll drastically reduces the CPU overhead associated with monitoring thousands of connections compared to older methods like select or poll. It scales very well with the number of connections.
• Suggestions:
  • Explicitly include it: While Nginx often defaults to the best method for the detected OS, it's good practice to explicitly include use epoll; in your events block if you're on Linux, as it clearly states your intent and ensures Nginx uses the most efficient method.

Overall Impact on Nginx Performance (CPU and Memory)

• CPU: worker_connections and the chosen use method directly impact CPU. A higher number of connections means more work for the CPU, but epoll minimizes the overhead of managing those connections.
• Memory: worker_connections directly influences memory consumption as each connection requires a small amount of memory. worker_rlimit_nofile ensures Nginx has enough capacity to use file descriptors but doesn't directly consume memory itself (it's a limit, not an allocation).

Your events block configuration is very aggressive and suitable for a high-performance web server aiming to handle significant traffic, which aligns with serving linuxmalaysia.com effectively. The high worker_connections and worker_rlimit_nofile values are excellent for scalability, provided your underlying operating system is also configured to support them.