Jiacai Liu jiacai2050

Docker Hub 镜像加速器

国内从 Docker Hub 拉取镜像有时会遇到困难，此时可以配置镜像加速器。Docker 官方和国内很多云服务商都提供了国内加速器服务。

Dockerized 实践 https://github.com/y0ngb1n/dockerized

配置加速地址

Ubuntu 16.04+、Debian 8+、CentOS 7+

CPU Usage :

(1 - avg(irate(node_cpu_seconds_total{mode="idle"}[10m])) by (instance)) * 100

Memory Usage :

100 * (1 - ((avg_over_time(node_memory_MemFree_bytes[10m]) + avg_over_time(node_memory_Cached_bytes[10m]) + avg_over_time(node_memory_Buffers_bytes[10m])) / avg_over_time(node_memory_MemTotal_bytes[10m])))

Async/Await - The challenges besides syntax - Cancellation

This is the second article in a series of articles around Rusts new async/await feature. The first article about interfaces can be found here.

In this part of the series we want to a look at a mechanism which behaves very different in Rust than in all other languages which feature async/await support. This mechanism is Cancellation.

Zig blog posts

This is intended as a place to list blog posts about Zig, for anyone who's interested in reading what people have to say! Also check out links at https://ziglang.org/learn/ and https://ziglang.org/news/.

Posts were found by searching on lobste.rs, at https://dev.to/t/zig and https://medium.com/tag/zig.

Please let me know in a comment if there are any posts missing that you'd like me to add here!

2021

`ld` – Wading through Mac OS X linker hell

Intro

Friend: I tried looking at static linking in Mac OS X and it seems nearly impossible. Take a look at this http://stackoverflow.com/a/3801032

Me: I have no idea what that -static flag does, but I'm pretty sure that's not how you link to a library. Let me RTFM a bit.

Minutes later...

Title Generator: http://www.bunstermedia.com/guru-ninja-rock-star/

Node - Nodesters
Ruby - rubyists
Python - pythonistas
Cocoa - Cocoa Heads
Go - Gophers
AngularJS - Angularians
EmberJS - Emberinos

Preferences

All preferences for the DNS-over-HTTPS functionality in Firefox are located under the "network.trr" prefix (TRR == Trusted Recursive Resolver).

network.trr.mode

set which resolver mode you want.

0 - Off (default). use standard native resolving only (don't use TRR at all)

1 - Race native against TRR. Do them both in parallel and go with the one that returns a result first.

	/*
	* Demo of libpq.
	* Build: g++ libpq-demo.cc -o libpq-demo -lpq
	* Run: ./libpq-demo
	*/

	#include <arpa/inet.h>
	#include <iostream>
	#include <libpq-fe.h>
	#include <sstream>

	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