lua-resty-beanstalkd - Lua beanstalkd client driver for the ngx_lua based on the cosocket API
Based on the lua-resty-memcached library.
Influenced by beanstalk-client-ruby
This library is currently very unstable. It is being written primarily for the author's education of ngx_lua cosockets.
Only the "put" and "delete" commands are supported. Only the default beanstalkd tube may be used.
This Lua library is a beanstalkd 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 0.5.0rc29 or ngx_openresty 1.0.15.7 is required.
lua_package_path "/path/to/lua-resty-beanstalkd/lib/?.lua;;";
server {
location /test {
content_by_lua '
local beanstalkd = require "resty.beanstalkd"
local b = beanstalkd.new()
local ok, err = b:connect()
if not ok then
ngx.say("failed to connect: ", err)
return
end
local ok, id, err = b:put("foo")
ngx.say(ok)
ok, err = b:delete(id)
ngx.say(ok)
b:close()
';
}
}
syntax: b, err = beanstalkd:new()
Creates a beanstalkd object. In case of failures, returns nil and a string describing the error.
syntax: ok, err = b:connect(host, port)
Attempts to connect to the remote host and port that the beanstalkd server is listening to or a local unix domain socket file listened by the beanstalkd server.
Before actually resolving the host name and connecting to the remote backend, this method will always look up the connection pool for matched idle connections created by previous calls of this method.
Host defaults to 127.0.0.1 and port defaults to 11300.
syntax: ok, id, err = b:put(body, pri, delay, ttr)
Inserts a job into the queue.
body should be a string.
pri is the priority and defaults to 65536
delay defaults to 0
ttr -- time to run -- defaults to 0
In case of success, returns true and the job id. On error, it will
return false, nil, and an error message.
syntax: ok, id, err = b:delete(id)
Deletes a job from the queue.
In case of success, returns true. On error, it will
return false and an error message.
syntax: b:set_timeout(time)
Sets the timeout (in ms) protection for subsequent operations, including the connect method.
syntax: ok, err = b:set_keepalive(max_idle_timeout, pool_size)
Keeps the current beanstalkd connection alive and put it into the ngx_lua cosocket connection pool.
You can specify the max idle timeout (in ms) when the connection is in the pool and the maximal size of the pool every nginx worker process.
In case of success, returns 1. In case of errors, returns nil with a string describing the error.
syntax: times, err = b:get_reused_times()
This method returns the (successfully) reused times for the current connection. In case of error, it returns nil and a string describing the error.
If the current connection does not come from the built-in connection pool, then this method always returns 0, that is, the connection has never been reused (yet). If the connection comes from the connection pool, then the return value is always non-zero. So this method can also be used to determine if the current connection comes from the pool.
syntax: ok, err = memc:close()
Closes the current beanstalkd connection and returns the status.
In case of success, returns 1. In case of errors, returns nil with a string describing the error.
- 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.beanstalkdobject 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 sameresty.beanstalkdinstance. You should always initiateresty.beanstalkdobjects in function local variables or in thengx.ctxtable. These places all have their own data copies for each request. - Only the default tube is used.
- Support the
usecommand. We may not want to do a round trip each time, so could we use socket pools and only issue ausewhen get_reusedtimes returns 0?
Brian Akins brian@akins.org
This module is licensed under the BSD license.
Copyright (C) 2012, by Brian Akins brian@akins.org.
Portions of the code are from lua-resty-memcached Copyright (C) 2012, by Zhang "agentzh" Yichun (章亦春) agentzh@gmail.com.
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.
- the ngx_lua module: http://wiki.nginx.org/HttpLuaModule
- the beanstalkd protocol specification: https://github.com/kr/beanstalkd/blob/master/doc/protocol.txt
- the lua-resty-memcached library.
- the lua-resty-redis library.
- the lua-resty-mysql library.