gearman2

Client library for Gearman

npm install gearman2
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gearman-node

This module lets you create Gearman clients with Node.js.

Only a subset of the features of Gearman are currently implemented.

Installation

$ npm install gearman

Usage

Clients

Creating a client goes something like this:

var gearman = require("gearman"),
    client = gearman.createClient(4730, "my-gearman-server.example.com");

console.log("Sending job...");
var job = client.submitJob("reverse", "Hello World!", { encoding: "utf8" });
job.on("complete", function (data) {
    console.log(data);
    client.end();
});

This creates a client with a job and a listener for the result.

You can run this on the command line like so:

$ node reverse-client.js
Sending job...
!dlroW olleH

More

Additional Gearman tutorials and help can be found at Gearman HQ help.

API

The gearman module contains methods for creating clients. You can include this module with require('gearman').

gearman.createClient([port = 4730], [host = 'localhost'])

Creates a new Gearman client. Takes port and host arguments which default to localhost:4730.

gearman.Client

This is an object with methods to create and manage jobs.

client.getConnection()

Creates and sets up a client's connection (an instance of net.Socket) if it has not yet been created and returns it.

client.end()

Closes the client connections for when you don't need to use the client any more.

client.submitJob(name, [data], [options])

Submits a job to a manager and returns a gearman.Job. data defaults to a Buffer, but can be a String if the encoding option is set to 'ascii', 'utf8', or 'base64'.

options is an object with the following defaults:

{ background: false,
  priority: 'normal',
  encoding: null
}

priority can be one of 'low', 'normal', or 'high'.

If background is set to true, the job is detached after the create event and no further events are emitted.

client.getJobStatus(handle, [callback])

Works the same as job.getStatus but takes a job handle (assigned previously by the server for a job submitted with background: true) and executes a callback taking an object with status information.

gearman.Job

An object representing a job that has been submitted. gearman.Job instances are EventEmitters with the these events:

Event: 'create'

function (handle) {}

Emitted when a job is created. handle is the new job's handle, which is also assigned to the handle property of the gearman.Job instance.

Event: 'data'

function (data) {}

Emitted when data for the job is received. data is the data sent, as a Buffer or as a String if encoding was set before the job was submitted.

Event: 'warning'

function (warning) {}

Same as a data event, but should be treated as a warning.

Event: 'complete'

function (data) {}

Emitted when a job completes. data is the data sent, as a Buffer or as a String if encoding was set before the job was submitted.

Event: 'fail'

function () {}

Emitted when a job fails.

job.getStatus([callback])

For a job that was submitted in the background (with background: true), get information about its status. callback will be called when the server returns the status, with an object showing status information:

job.getStatus(function (status) { console.dir(status); });

The status object returned can contain the following:

{ handle: String,                   // the job's handle
  known: Boolean,                   // is the job known?
  running: Boolean,                 // is the job running?
  percentComplete: [Number, Number] // Numerator & denominator of percentage complete
}

Tests

To run the tests:

Set up nodeunit:

$ npm link

Some of the tests require a live Gearman server running on localhost:4730 (no mock server here, we keep it real.) Download, install, and run gearmand. You can do brew install gearman on a Mac with HomeBrew.

A worker used by some of the tests is in the test/fixtures directory. You'll need the gearman gem installed and you can run it with:

$ ruby test/fixtures/worker.rb &

Run the tests:

$ nodeunit test

Compatibility

Should be compatible with node 0.4.x.

Should work with Gearman 0.20 and Gearman HQ.

Contributors

Thanks to the Gearman community and rest of the Gearman HQ team for help and documentation. This module is mostly based on gearman-ruby and gearman.net.

Thanks to the Node.js community for excellent people, tools, resources, examples, documentation, and inspiration.

License

Copyright (c) 2011 Nathan L Smith

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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