Name

lua-resty-gearman - Lua gearman client driver for the ngx_lua based on the cosocket API

Status

This library is considered experimental and still under active development.

Description

This Lua library is a Gearman client driver for the ngx_lua nginx module:

http://wiki.nginx.org/HttpLuaModule

This Lua library takes advantage of ngx_lua's cosocket API, which ensures 100% nonblocking behavior.

Note that at least ngx_lua 0.5.14 or ngx_openresty 1.2.1.14 is required.

Synopsis

lua_package_path "/path/to/lua-resty-gearman/lib/?.lua;;";

server {
    location /test {
        content_by_lua '
            local gearman = require "resty.gearman"
            local gm = gearman:new()

            gm:set_timeout(1000) -- 1 sec

            local ok, err = gm:connect("127.0.0.1", 4730)
            if not ok then
                ngx.say("failed to connect: ", err)
                return
            end

            ok, err = gm:submit_job("wc", "11111\n22222\n33333")  
            -- submit_job,submit_job_bg,submit_job_high,submit_job_high_bg,submit_job_low,submit_job_low_bg are supported
            -- submit_job(function_name, workload[, unique])
            
            if not ok then
                ngx.say("failed to submit job: ", err)
                return
            else
                ngx.say(ok)                
            end

            -- put it into the connection pool of size 100,
            -- with 0 idle timeout
            local ok, err = gm:set_keepalive(0, 100)
            if not ok then
                ngx.say("failed to set keepalive: ", err)
                return
            end

            -- or just close the connection right away:
            -- local ok, err = gm:close()
            -- if not ok then
            --     ngx.say("failed to close: ", err)
            --     return
            -- end
        ';
    }
}

Methods

Limitations

• Now only client tasks(submit_job,submit_job_bg,submit_job_high,submit_job_high_bg,submit_job_low,submit_job_low_bg) are supported.
• This library cannot be used in code contexts like set_by_lua*, log_by_lua*, and header_filter_by_lua* where the ngx_lua cosocket API is not available.
• The resty.gearman object instance cannot be stored in a Lua variable at the Lua module level, because it will then be shared by all the concurrent requests handled by the same nginx worker process (see http://wiki.nginx.org/HttpLuaModule#Data_Sharing_within_an_Nginx_Worker ) and result in bad race conditions when concurrent requests are trying to use the same resty.gearman instance. You should always initiate resty.gearman objects in function local variables or in the ngx.ctx table. These places all have their own data copies for each request.

Installation

If you are using the ngx_openresty bundle (http://openresty.org ), then you don't need to do anything because it already includes and enables lua-resty-gearman by default. And you can just use it in your Lua code, as in

local gearman = require "resty.gearman"
...

If you're using your own nginx + ngx_lua build, then you need to configure the lua_package_path directive to add the path of your lua-resty-gearman source tree to ngx_lua's LUA_PATH search path, as in

# nginx.conf
http {
    lua_package_path "/path/to/lua-resty-gearman/lib/?.lua;;";
    ...
}

TODO

Community

English Mailing List

The openresty-en mailing list is for English speakers.

Chinese Mailing List

The openresty mailing list is for Chinese speakers.

Bugs and Patches

Please report bugs or submit patches by

1. creating a ticket on the GitHub Issue Tracker

Author

Zhihua Chen (陈智华) [email protected]

Copyright and License

This module is licensed under the BSD license.

Copyright (C) 2012, by Zhihua Chen (陈智华) [email protected].

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.

See Also

• the ngx_lua module: http://wiki.nginx.org/HttpLuaModule
• the gearman protocol specification: http://gearman.org/doku.php?id=protocol