rediz

Multifunction redis client library. In general, mimics the interface of node-redis.

Has the following features:

• Stored functions
• Volatile-redis-cluster sharding
• Conversion from callbacks to promises
• Conversion of all errors to XError's
• master client and shards can use all redis commands

Basic Usage

Example of non-volatile cluster.

let RedizClient = require('rediz');
let rediz = new RedizClient({ host: 'localhost', port: 6379, volatileCluster: false });
 
rediz.registerScriptDir('/path/to/redis/scripts');
rediz.runScript('doSomething', arg1, arg2).then(...);

Example of volatile cluster

let RedizClient = require('rediz');
let rediz = new RedizClient({ host: 'localhost', port: 6379, volatileCluster: true });
let shard = rediz.shard('myKey');
 
rediz.registerScriptDir('/path/to/redis/scripts');
shard.runScript('doSomething', arg1, arg2).then(...);

Ways to register scripts

All scripts that are registered on the master client, will be availble to any shards created before or after, the script has been registered. Registering scripts can be done on either master or any of the shards. If it is done on a shard then the master client will not have access to that script. The two examples above use the registerScriptDir, which will read all the files with the extension lua. It will name that script, after the name of the file.

Example register a script from a single file.

NOTE when registering a script from a file, or a directory, the script will be parsed to find the numKeyArgs for redis. So make sure that is defined at the top of the file.

let RedizClient = require('rediz');
let rediz = new RedizClient({ host: 'localhost', port: 6379, volatileCluster: true });
 
rediz.registerScriptFile('test', 'path/to/redis/script.lua');
rediz.runScript('test', arg1, arg2,).then(...);

Example register a script from text

let scriptText = 'local numKeyArgs = 1\n\r' +
    'redis.call("set", KEYS[1], ARGV[1])\n\r' +
    'redis.call("incr", KEYS[1])\n\r' +
    'local result = redis.call("get", KEYS[1])\n\r' +
    'redis.call("del", KEYS[1])\n\r' +
    'return result';
 
let RedizClient = require('rediz');
let rediz = new RedizClient({ host: 'localhost', port: 6379, volatileCluster: true });
let shard;
 
redis.registerScript('foo', scriptText, { numKeyArgs: 1 }); // if numKeyArgs is not defined the text will be parsed the same as the files.
    .then( () => shard =  redis.shard('aKey') )
    .then( () => shard.runScript('foo', '') )
    .then( (result) => return result );