# Guard [](https://travis-ci.org/jiajunhuang/guard) [](https://codecov.io/gh/jiajunhuang/guard)  guard is a generic high performance circuit breaker & proxy written in Go. It has four major components: - radix tree & response status ring: which stores registered URLs - load balancer: which distributes requests(algorithms: randomized distribute, round robin, weighted round robin) - circuit breaker: which makes sure your backend services will not be broken down by a large quantity of requests - proxy server: it's based on fasthttp ## Workflow  ## Benchmark I've made a simple benchmark on my laptop(i5-3210M CPU @ 2.50GHz with 4 cores): ```bash $ wrk --latency -H "Host: www.example.com" -c 2048 -d 30 -t 2 http://127.0.0.1:9999 # Nginx with 4 workers Running 30s test @ http://127.0.0.1:9999 2 threads and 2048 connections Thread Stats Avg Stdev Max +/- Stdev Latency 99.62ms 158.44ms 1.36s 95.41% Req/Sec 6.43k 2.43k 11.36k 53.85% Latency Distribution 50% 58.34ms 75% 153.81ms 90% 165.62ms 99% 965.10ms 383670 requests in 30.09s, 311.00MB read Socket errors: connect 1029, read 0, write 0, timeout 114 Requests/sec: 12749.73 Transfer/sec: 10.33MB $ wrk --latency -H "Host: www.example.com" -c 2048 -d 30 -t 2 http://127.0.0.1:23456 # guard with GOMAXPROCS=4 Running 30s test @ http://127.0.0.1:23456 2 threads and 2048 connections Thread Stats Avg Stdev Max +/- Stdev Latency 45.78ms 34.36ms 1.12s 89.09% Req/Sec 11.35k 1.18k 14.19k 73.20% Latency Distribution 50% 41.87ms 75% 56.55ms 90% 74.52ms 99% 111.06ms 676392 requests in 30.07s, 532.82MB read Socket errors: connect 1029, read 0, write 0, timeout 0 Requests/sec: 22494.06 Transfer/sec: 17.72MB ``` For now, guard's proxy performance is about ~~55% of Nginx~~ **1.76x** faster than Nginx, and **I'm still working on it! Don't worry, it will become better and better!** By the way, ~~thanks the [suggestion](https://github.com/jiajunhuang/guard/issues/15) from [@dongzerun](https://github.com/dongzerun), by configure the `GOGC` in environment, guard's proxy performance is about 70% of Nginx.~~ guard does not allocate much memory now, `GOGC` does not make a change, but still say thanks to [@dongzerun](https://github.com/dongzerun)! ## TODO moved to https://github.com/jiajunhuang/guard/projects/1 ## Set it up 1. build it using `go get -u`: ```bash $ go get -u github.com/jiajunhuang/guard ``` 2. start it ```bash $ guard ``` 3. now you need to register an application by send a POST request to `http://127.0.0.1:12345/app` with json like this: ```json { "name": "www.example.com", "backends": ["127.0.0.1:80", "127.0.0.1:80", "127.0.0.1:80"], "weights": [5, 1, 1], "ratio": 0.3, "paths": ["/"], "methods": ["GET"], "fallback_type": "text", "fallback_content": "hello world" } ``` I'm doing it like this: ```bash $ http POST :12345/app < backends.json HTTP/1.1 200 OK Content-Length: 8 Content-Type: text/plain; charset=utf-8 Date: Sun, 21 Jan 2018 08:51:16 GMT success! ``` 4. and now, it works! whoops! try it: ```bash $ http :23456 'Host: www.example.com' HTTP/1.1 200 OK ... ``` 5. by the way, you can inspect your configuration by visit http://127.0.0.1:12345/ : ```bash $ http :12345 HTTP/1.1 200 OK Content-Length: 235 Content-Type: application/json Date: Fri, 26 Jan 2018 14:11:02 GMT { "apps": { "www.example.com": { "backends": [ "127.0.0.1:80", "127.0.0.1:80", "127.0.0.1:80" ], "disable_tsr": false, "load_balance_method": "rr", "methods": [ "GET", "GET" ], "name": "www.example.com", "paths": [ "/", "/doc" ], "ratio": 0.3, "weights": [ 5, 1, 1 ] } } } ``` ## Changelogs - 2018-01-25: rewrite proxy from `net/http` to `fasthttp`, it's super fast now! - 2018-01-24: rewrite radix tree & statistics module, it's lock-free now! - 2018-01-22: add randomized distribute, naive round robin algorithms - 2018-01-21: rewrite status statistics module - 2018-01-20: guard works! - 2018-01-19: first commit ## Thanks - [Golang](https://golang.org) - [fasthttp](https://github.com/valyala/fasthttp) - [httprouter](https://github.com/jiajunhuang/httprouter)