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lua-resty-riak

lua-resty-riak - Lua riak protocol buffer client driver for the ngx_lua based on the cosocket API.

Originally based on the lua-resty-memcached library.

Status

This library is currently alpha quality. It passes all its unit tests. A few billion requests per day are handled by it however.

Description

This Lua library is a riak protocol buffer client driver for the ngx_lua nginx module

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.

Depends on the following Lua modules:

lua-pb - https://github.com/Neopallium/lua-pb
struct - http://www.inf.puc-rio.br/~roberto/struct/
lpack - http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/#lpack

Synopsis

lua_package_path "/path/to/lua-resty-riak/lib/?.lua;;";
location /t {
    content_by_lua '
        require "luarocks.loader"
        local riak = require "resty.riak"
        local client = riak.new()
        local ok, err = client:connect("127.0.0.1", 8087)
        if not ok then
            ngx.log(ngx.ERR, "connect failed: " .. err)
        end
        local bucket = client:bucket("test")
        local object = bucket:new("1")
        object.value = "test"
        object.content_type = "text/plain"
        local rc, err = object:store()
        ngx.say(rc)
        local object, err = bucket:get("1")
        if not object then
            ngx.say(err)
        else
            ngx.say(object.value)
        end
        client:close()
    ';
}

Usage

See the generated docs for usage and examples.

Note The high level API should be considered stable - ie will not break between minor versions. The low-level or raw API should not be considered stable.

Potentially Breaking Change in 2.0

2.0.0 now uses vector clocks for gets,sets, and deletes of objects. If you are using a bucket that allows multiple values (siblings) then this may break your application.

Limitations

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.riak object instances 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 Data Sharing within an Nginx Worker ) and result in bad race conditions when concurrent requests are trying to use the same instances. You should always initiate these objects in function local variables or in the ngx.ctx table. These places all have their own data copies for each request.

TODO

Author

Brian Akins brian@akins.org

Heavily influenced by Zhang "agentzh" Yichun (章亦春) agentzh@gmail.com.

Copyright and License

This module is licensed under the BSD license.

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.