| 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 |
| var cluster = require('cluster'); | |
| var http = require('http'); | |
| var numCPUs = require('os').cpus().length; | |
| if (cluster.isMaster) { | |
| // Fork workers. | |
| for (var i = 0; i < numCPUs; i++) { | |
| cluster.fork(); | |
| } | |
| cluster.on('exit', function(worker, code, signal) { |
In August 2007 a hacker found a way to expose the PHP source code on facebook.com. He retrieved two files and then emailed them to me, and I wrote about the issue:
http://techcrunch.com/2007/08/11/facebook-source-code-leaked/
It became a big deal:
http://www.techmeme.com/070812/p1#a070812p1
The two files are index.php (the homepage) and search.php (the search page)
| # Building static nginx for teh lulz | |
| # | |
| # basic dependencies | |
| sudo apt-get install libxslt1-dev libxml2-dev zlib1g-dev libpcre3-dev libbz2-dev libssl-dev | |
| # download nginx and openssl | |
| wget http://nginx.org/download/nginx-1.5.6.tar.gz | |
| tar xf nginx-1.5.6.tar.gz; cd nginx-1.5.6 |
There are a lot of ways to serve a Go HTTP application. The best choices depend on each use case. Currently nginx looks to be the standard web server for every new project even though there are other great web servers as well. However, how much is the overhead of serving a Go application behind an nginx server? Do we need some nginx features (vhosts, load balancing, cache, etc) or can you serve directly from Go? If you need nginx, what is the fastest connection mechanism? This are the kind of questions I'm intended to answer here. The purpose of this benchmark is not to tell that Go is faster or slower than nginx. That would be stupid.
So, these are the different settings we are going to compare:
| // Traverses an arbitrary struct and translates all stings it encounters | |
| // | |
| // I haven't seen an example for reflection traversing an arbitrary struct, so | |
| // I want to share this with you. If you encounter any bugs or want to see | |
| // another example please comment. | |
| // | |
| // The MIT License (MIT) | |
| // | |
| // Copyright (c) 2014 Heye Vöcking | |
| // |
| package main | |
| import ( | |
| "reflect" | |
| "strings" | |
| ) | |
| func makeChannel(t reflect.Type, chanDir reflect.ChanDir, buffer int) reflect.Value { | |
| ctype := reflect.ChanOf(chanDir, t) | |
| return reflect.MakeChan(ctype, buffer) |
| #!/bin/bash -e | |
| echo ' | |
| PATH=$HOME/go/bin:$PATH | |
| export GOPATH=$HOME | |
| export CDPATH=.:$HOME/src/golang.org/x:$HOME/go/src:$HOME/src/github.com:$HOME/src/github.com/nf:$HOME/src/github.com/adg | |
| export EDITOR=vim | |
| ' >> ~/.profile | |
| sudo apt-get update |
| \n | |
| ============= HOST: ==========\n | |
| \n | |
| local_ip: %{local_ip}\n | |
| local_port: %{local_port}\n | |
| remote_ip: %{remote_ip}\n | |
| remote_port: %{remote_port}\n | |
| \n | |
| ======= CONNECTION: ==========\n | |
| \n |
At Vimeo, on the transcoding team, we work a lot with Go, and a lot with C, for various tasks such as media ingest. This means we use CGO quite extensively, and consequently, have run into bits that are perhaps not very well documented, if at all. Below is my effort to document some of the problems we've run into, and how we fixed or worked around them.
Many of these are obviously wrong in retrospect, but hindsight is 20/20, and these problems do exist in many codebases currently.
Some are definitely ugly, and I much welcome better solutions! Tweet me at @daemon404 if you have any, or have your own CGO story/tips, please! I'd love to learn of them.
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