lua-cassandra

A pure Lua client library for Apache Cassandra (2.x/3.x), compatible with OpenResty.

This library offers 2 modules: a "single host" module (cassandra), compatible with PUC Lua 5.1/5.2, LuaJIT and OpenResty, which allows your application to connect itself to a given Cassandra node, and a "cluster" module (resty.cassandra.cluster), only compatible with OpenResty which adds support for multi-node Cassandra datacenters.

The following table describes which version(s) of the binary protocol is supported by each Cassandra version:


Cassandra VersionBinary Protocol support
1.21
2.01, 2
2.11, 2, 3
2.21, 2, 3, 4
3.03, 4


This library supports binary protocols 2 and 3, hence supports Cassandra 2.x and 3.x only.

Installation

With Luarocks:

$ luarocks install lua-cassandra

Manually:

Once you have a local copy of this module's lib/ directory, add it to your LUA_PATH (or lua_package_path directive for OpenResty):

 /path/to/lib/?.lua;/path/to/lib/?/init.lua;

Note: When used outside of OpenResty, or in the init_by_lua context, this module requires additional dependencies:

Usage

Single host module (Lua and OpenResty):

local cassandra = require "cassandra"

local peer = assert(cassandra.new {
  host = "127.0.0.1",
  port = 9042,
  keyspace = "my_keyspace"
})

peer:settimeout(1000)

assert(peer:connect())

assert(peer:execute("INSERT INTO users(id, name, age) VALUES(?, ?, ?)", {
  cassandra.uuid("1144bada-852c-11e3-89fb-e0b9a54a6d11"),
  "John O Reilly",
  42
}))

local rows = assert(peer:execute "SELECT * FROM users")

local user = rows[1]
print(user.name) -- John O Reilly
print(user.age)  -- 42

peer:close()

Cluster module (OpenResty only):

 http {
     # you do not need the following line if you are using luarocks
     lua_package_path "/path/to/src/?.lua;/path/to/src/?/init.lua;;";

     # all cluster informations will be stored here
     lua_shared_dict cassandra 1m;

     server {
         ...

         location / {
             content_by_lua_block {
                 local Cluster = require 'resty.cassandra.cluster'

                 -- can live in an upvalue at the main chunk level of your
                 -- modules, to avoid creating it on every request.
                 -- see the intro example in the documentation.
                 local cluster, err = Cluster.new {
                     shm = 'cassandra', -- defined by the lua_shared_dict directive
                     contact_points = {'127.0.0.1', '127.0.0.2'},
                     keyspace = 'my_keyspace'
                 }
                 if not cluster then
                     ngx.log(ngx.ERR, 'could not create cluster: ', err)
                     return ngx.exit(500)
                 end

                 local rows, err = cluster:execute "SELECT * FROM users"
                 if not rows then
                     ngx.log(ngx.ERR, 'could not retrieve users: ', err)
                     return ngx.exit(500)
                 end

                 ngx.say('users: ', #rows)
             }
         }
     }
 }

See the cassandra and resty.cassandra.cluster modules references for a detailed list of available methods and options.

Examples

Also check out the examples section for concrete examples of basic and advanced usage.

Credits

This project was originally a fork of jbochi/lua-resty-cassandra with bugfixes and new features. It was completely rewritten in its 0.4.0 version to allow serious improvements in terms of features and maintainability.

License

The MIT License (MIT)

Original work Copyright (c) 2016 Thibault Charbonnier Based on the work of Juarez Bochi Copyright 2014

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

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