# lua-resty-balancer **Repository Path**: colinyyj/lua-resty-balancer ## Basic Information - **Project Name**: lua-resty-balancer - **Description**: No description available - **Primary Language**: Unknown - **License**: Not specified - **Default Branch**: master - **Homepage**: None - **GVP Project**: No ## Statistics - **Stars**: 0 - **Forks**: 1 - **Created**: 2024-08-30 - **Last Updated**: 2024-08-30 ## Categories & Tags **Categories**: Uncategorized **Tags**: None ## README Name ==== lua-resty-chash - A generic consistent hash implementation for OpenResty/LuaJIT lua-resty-roundrobin - A generic roundrobin implementation for OpenResty/LuaJIT Table of Contents ================= * [Name](#name) * [Status](#status) * [Description](#description) * [Synopsis](#synopsis) * [Methods](#methods) * [new](#new) * [reinit](#reinit) * [set](#set) * [delete](#delete) * [incr](#incr) * [decr](#decr) * [find](#find) * [next](#next) * [Installation](#installation) * [Performance](#performance) * [Author](#author) * [Copyright and License](#copyright-and-license) * [See Also](#see-also) Status ====== This library is still under early development and is still experimental. Description =========== This Lua library can be used with `balancer_by_lua*`. Synopsis ======== ```lua lua_package_path "/path/to/lua-resty-chash/lib/?.lua;;"; lua_package_cpath "/path/to/lua-resty-chash/?.so;;"; init_by_lua_block { local resty_chash = require "resty.chash" local resty_roundrobin = require "resty.roundrobin" local resty_swrr = require "resty.swrr" local server_list = { ["127.0.0.1:1985"] = 2, ["127.0.0.1:1986"] = 2, ["127.0.0.1:1987"] = 1, } -- XX: we can do the following steps to keep consistency with nginx chash local str_null = string.char(0) local servers, nodes = {}, {} for serv, weight in pairs(server_list) do -- XX: we can just use serv as id when we doesn't need keep consistency with nginx chash local id = string.gsub(serv, ":", str_null) servers[id] = serv nodes[id] = weight end local chash_up = resty_chash:new(nodes) package.loaded.my_chash_up = chash_up package.loaded.my_servers = servers local rr_up = resty_roundrobin:new(server_list) package.loaded.my_rr_up = rr_up local swrr_up = resty_swrr:new(server_list) package.loaded.my_swrr_up = swrr_up } upstream backend_chash { server 0.0.0.1; balancer_by_lua_block { local b = require "ngx.balancer" local chash_up = package.loaded.my_chash_up local servers = package.loaded.my_servers -- we can balancer by any key here local id = chash_up:find(ngx.var.arg_key) local server = servers[id] assert(b.set_current_peer(server)) } } upstream backend_rr { server 0.0.0.1; balancer_by_lua_block { local b = require "ngx.balancer" local rr_up = package.loaded.my_rr_up -- Note that Round Robin picks the first server randomly local server = rr_up:find() assert(b.set_current_peer(server)) } } upstream backend_swrr { server 0.0.0.1; balancer_by_lua_block { local b = require "ngx.balancer" local swrr_up = package.loaded.my_swrr_up -- Note that SWRR picks the first server randomly local server = swrr_up:find() assert(b.set_current_peer(server)) } } server { location /chash { proxy_pass http://backend_chash; } location /roundrobin { proxy_pass http://backend_rr; } location /swrr { proxy_pass http://backend_swrr; } } ``` [Back to TOC](#table-of-contents) Methods ======= Both `resty.chash`, `resty.roundrobin` and `resty.swrr` have the same apis. [Back to TOC](#table-of-contents) new --- **syntax:** `obj, err = class.new(nodes)` Instantiates an object of this class. The `class` value is returned by the call `require "resty.chash"`. The `id` should be `table.concat({host, string.char(0), port})` like the nginx chash does, when we need to keep consistency with nginx chash. The `id` can be any string value when we do not need to keep consistency with nginx chash. The `weight` should be a non negative integer. ```lua local nodes = { -- id => weight server1 = 10, server2 = 2, } local resty_chash = require "resty.chash" local chash = resty_chash:new(nodes) local id = chash:find("foo") ngx.say(id) ``` [Back to TOC](#table-of-contents) reinit -------- **syntax:** `obj:reinit(nodes)` Reinit the chash obj with the new `nodes`. [Back to TOC](#table-of-contents) set -------- **syntax:** `obj:set(id, weight)` Set `weight` of the `id`. [Back to TOC](#table-of-contents) delete -------- **syntax:** `obj:delete(id)` Delete the `id`. [Back to TOC](#table-of-contents) incr -------- **syntax:** `obj:incr(id, weight?)` Increments weight for the `id` by the step value `weight`(default to 1). [Back to TOC](#table-of-contents) decr -------- **syntax:** `obj:decr(id, weight?)` Decrease weight for the `id` by the step value `weight`(default to 1). [Back to TOC](#table-of-contents) find -------- **syntax:** `id, index = obj:find(key)` Find an id by the `key`, same key always return the same `id` in the same `obj`. The second return value `index` is the index in the chash circle of the hash value of the `key`. [Back to TOC](#table-of-contents) next -------- **syntax:** `id, new_index = obj:next(old_index)` If we have chance to retry when the first `id`(server) doesn't work well, then we can use `obj:next` to get the next `id`. The new `id` may be the same as the old one. [Back to TOC](#table-of-contents) Installation ============ First you need to run `make` to generate the librestychash.so. Then you need to configure the lua_package_path and lua_package_cpath directive to add the path of your lua-resty-chash source tree to ngx_lua's LUA_PATH search path, as in ```nginx # nginx.conf http { lua_package_path "/path/to/lua-resty-chash/lib/?.lua;;"; lua_package_cpath "/path/to/lua-resty-chash/?.so;;"; ... } ``` Ensure that the system account running your Nginx ''worker'' proceses have enough permission to read the `.lua` and `.so` file. [Back to TOC](#table-of-contents) Performance =========== There is a benchmark script `t/bench.lua`. I got the result when I run `make bench`: ``` chash new servers 10000 times elasped: 0.61600017547607 chash new servers2 1000 times elasped: 0.77300000190735 chash new servers3 10000 times elasped: 0.66899991035461 new in func 10000 times elasped: 0.62000012397766 new dynamic 10000 times elasped: 0.75499987602234 incr server3 10000 times elasped: 0.19000029563904 incr server1 10000 times elasped: 0.33699989318848 decr server1 10000 times elasped: 0.27300024032593 delete server3 10000 times elasped: 0.037999868392944 delete server1 10000 times elasped: 0.065000057220459 set server1 9 10000 times elasped: 0.26600003242493 set server1 8 10000 times elasped: 0.32000017166138 set server1 1 10000 times elasped: 0.56699991226196 base for find 1000000 times elasped: 0.01800012588501 find 1000000 times elasped: 0.9469997882843 ``` [Back to TOC](#table-of-contents) Author ====== Dejiang Zhu (doujiang24) . [Back to TOC](#table-of-contents) Copyright and License ===================== This module is licensed under the BSD license. Copyright (C) 2015-2016, by Yichun Zhang (agentzh) , CloudFlare Inc. All rights reserved. Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met: * Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer. * Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution. THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. [Back to TOC](#table-of-contents) See Also ======== * the ngx_lua module: http://wiki.nginx.org/HttpLuaModule * the json lib for Lua and C: https://github.com/cloudflare/lua-resty-json [Back to TOC](#table-of-contents)