dky

Docker - How to cleanup (unused) resources

Once in a while, you may need to cleanup resources (containers, volumes, images, networks) ...

delete volumes

// see: https://github.com/chadoe/docker-cleanup-volumes

$ docker volume rm $(docker volume ls -qf dangling=true)

$ docker volume ls -qf dangling=true | xargs -r docker volume rm

Rich Hickey on becoming a better developer

Rich Hickey • 3 years ago

Sorry, I have to disagree with the entire premise here.

A wide variety of experiences might lead to well-roundedness, but not to greatness, nor even goodness. By constantly switching from one thing to another you are always reaching above your comfort zone, yes, but doing so by resetting your skill and knowledge level to zero.

Mastery comes from a combination of at least several of the following:

Moved to git repository: https://github.com/denji/nginx-tuning

NGINX Tuning For Best Performance

For this configuration you can use web server you like, i decided, because i work mostly with it to use nginx.

Generally, properly configured nginx can handle up to 400K to 500K requests per second (clustered), most what i saw is 50K to 80K (non-clustered) requests per second and 30% CPU load, course, this was 2 x Intel Xeon with HyperThreading enabled, but it can work without problem on slower machines.

You must understand that this config is used in testing environment and not in production so you will need to find a way to implement most of those features best possible for your servers.

tmux cheatsheet

As configured in my dotfiles.

start new:

tmux

start new with session name:

	#cloud-config

	coreos:
	etcd:
	# generate a new token for each unique cluster from https://discovery.etcd.io/new
	discovery: https://discovery.etcd.io/<token>
	# multi-region deployments, multi-cloud deployments, and droplets without
	# private networking need to use $public_ipv4
	addr: $private_ipv4:4001
	peer-addr: $private_ipv4:7001

	Latency Comparison Numbers (~2012)
	----------------------------------
	L1 cache reference 0.5 ns
	Branch mispredict 5 ns
	L2 cache reference 7 ns 14x L1 cache
	Mutex lock/unlock 25 ns
	Main memory reference 100 ns 20x L2 cache, 200x L1 cache
	Compress 1K bytes with Zippy 3,000 ns 3 us
	Send 1K bytes over 1 Gbps network 10,000 ns 10 us
	Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD

	# replace PAPERTRAIL_HOSTNAME and PAPERTRAIL_PORT
	# see http://help.papertrailapp.com/ for additional PHP syslog options

	function send_remote_syslog($message, $component = "web", $program = "next_big_thing") {
	$sock = socket_create(AF_INET, SOCK_DGRAM, SOL_UDP);
	foreach(explode("\n", $message) as $line) {
	$syslog_message = "<22>" . date('M d H:i:s ') . $program . ' ' . $component . ': ' . $line;
	socket_sendto($sock, $syslog_message, strlen($syslog_message), 0, PAPERTRAIL_HOSTNAME, PAPERTRAIL_PORT);
	}
	socket_close($sock);

	.gist-highlight {
	border-left: 3ex solid #eee;
	position: relative;
	}

	.gist-highlight pre {
	counter-reset: linenumbers;
	}

	.gist-highlight pre div:before {

	# Usage:
	# source iterm2.zsh

	# iTerm2 tab color commands
	# https://iterm2.com/documentation-escape-codes.html

	if [[ -n "$ITERM_SESSION_ID" ]]; then
	tab-color() {
	echo -ne "\033]6;1;bg;red;brightness;$1\a"
	echo -ne "\033]6;1;bg;green;brightness;$2\a"

	# to generate your dhparam.pem file, run in the terminal
	openssl dhparam -out /etc/nginx/ssl/dhparam.pem 2048