= Name =
nginx_http_upstream_check_module - support health check with Nginx
Add the support of health check with the upstream servers.
syntax: check interval=milliseconds [fall=count] [rise=count] [timeout=milliseconds] [default_down=true|false] [type=tcp|ssl_hello|mysql|ajp]
default: none, if parameters omitted, default parameters are interval=30000 fall=5 rise=2 timeout=1000 default_down=true type=tcp
context: upstream
description: Add the health check for the upstream servers.
The parameters' meanings are:
- interval: the check request's interval time.
- fall(fall_count): After fall_count check failures, the server is marked down.
- rise(rise_count): After rise_count check success, the server is marked up.
- timeout: the check request's timeout.
- default_down: set initial state of backend server, default is down.
- type: the check protocol type:
- tcp is a simple tcp socket connect and peek one byte.
- ssl_hello sends a client ssl hello packet and receives the server ssl hello packet.
- http sends a http request packet, receives and parses the http response to diagnose if the upstream server is alive.
- mysql connects to the mysql server, receives the greeting response to diagnose if the upstream server is alive.
- ajp sends a AJP Cping packet, receives and parses the AJP Cpong response to diagnose if the upstream server is alive.
syntax: check_http_send http_packet
default: "GET / HTTP/1.0\r\n\r\n"
context: upstream
description: If you set the check type is http, then the check function will sends this http packet to check the upstream server.
syntax: check_http_expect_alive [http_2xx]
default: http_2xx | http_3xx
context: upstream
description: These status codes indicate the upstream server's http response is ok, the backend is alive.
syntax: check_shm_size size
default: 1m
context: http
description: Default size is one megabytes. If you check thousands of servers, the shared memory for health check may be not enough, you can enlarge it with this directive.
syntax: check_status
default: none
context: location
description: Display the health checking servers' status by HTTP. This directive should be set in the http block.
Download the latest version of the release tarball of this module from github
Grab the nginx source code from nginx.org, for example, the version 1.0.14 (see nginx compatibility), and then build the source with this module:
<geshi lang="bash"> $ wget 'http://nginx.org/download/nginx-1.0.14.tar.gz' $ tar -xzvf nginx-1.0.14.tar.gz $ cd nginx-1.0.14/ $ patch -p1 < /path/to/nginx_http_upstream_check_module/check.patch $ ./configure --add-module=/path/to/nginx_http_upstream_check_module $ make $ make install </geshi>If you use nginx-1.2.1 or nginx-1.3.0, the nginx upstream round robin module changed greatly. You should use the patch named 'check_1.2.1.patch'.
If you use nginx-1.2.2+ or nginx-1.3.1+, It added the upstream least_conn module. You should use the patch named 'check_1.2.2+.patch'.
The patch just adds the support for the official Round-Robin, Ip_hash and least_conn upstream module. But it's easy to expand my module to other upstream modules. See the patch for detail.
If you want to add the support for upstream fair module, you can do it like this:
<geshi lang="bash"> $ git clone git://github.com/gnosek/nginx-upstream-fair.git $ cd nginx-upstream-fair $ patch -p2 < /path/to/nginx_http_upstream_check_module/upstream_fair.patch $ cd /path/to/nginx-1.0.14 $ ./configure --add-module=/path/to/nginx_http_upstream_check_module --add-module=/path/to/nginx-upstream-fair-module $ make $ make install </geshi>
If you want to add the support for nginx sticky module, you can do it like this:
<geshi lang="bash"> $ svn checkout http://nginx-sticky-module.googlecode.com/svn/trunk/ nginx-sticky-module $ cd nginx-sticky-module $ patch -p0 < /path/to/nginx_http_upstream_check_module/nginx-sticky-module.patch $ cd /path/to/nginx-1.0.14 $ ./configure --add-module=/path/to/nginx_http_upstream_check_module --add-module=/path/to/nginx-sticky-module $ make $ make install </geshi>
Note that, the nginx-sticky-module also needs the original check.patch.
- My test bed is 0.7.67 and 0.8.49+.
- Developing
- first release
Weibin Yao(姚伟斌) yaoweibin at gmail dot com
Matthieu Tourne
This README template copy from agentzh.
The health check part is borrowed the design of Jack Lindamood's healthcheck module healthcheck_nginx_upstreams;
This module is licensed under the BSD license.
Copyright (C) 2012 by Weibin Yao <yaoweibin@gmail.com></yaoweibin@gmail.com>.
Copyright (C) 2012 by Matthieu Tourne.
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.