artwells/meteor-queue

Job Queue for Meteor.js

meteor-queue

Job Queue for Meteor.js, backed by Mongo and setInterval

Features

• queued tasks executed by set priorities
• start/stop/change setInterval events
• schedule queued events in the future
• logging of critical events with optional verbose logging
• queue-wide and entry-level locking to avoid processing
• ability to requeue failed jobs at event-level configurable interval (for jobs set to fail at high-load or peak times)
• optional "non-ready" default state -- allowing some tasks to require operational blessing
• queues are stored in Mongo collections (queue and queuelog)
• option to purge ephemeral logs at higher frequency
• fairly complete tests
• setInterval group for handling Queue-specific tasks
• option integration with houston:admin allowing limited GUI manipulation (changing/deleting/run now queued task, changing, stopping setInterval taks)

Installation

meteor add artwells:queue

add to a server.js or common file:

if (Meteor.isServer) {
  Meteor.startup(function () {
	// code to run on server at startup
	Queue.add({command:'console.log("queue called now");'});
	console.log('about to run queue');
  });
}

Options

• Queue.loglevel, default 3. 3 only includes lock conflicts. 2, 3 includes successes.

• Queue.logLife, default 30. Days to keep logfiles.

• Queue.ephemeralLogLife, default 1800000. milliseconds to keep ephemeral log statuses

• Queue.ephemeralLogStatuses, default ['lockfailed','success']. statuses to purge from logs quickly;

• Queue.defaultPriority, default 5. 1 is highest.

• Queue.defaultStatus, default pending. By changing this to some other new word, you can make sure queue items are "blessed" in "pending" through another process.

• Queue.keepsuccess, default true. Keep successful jobs in the queue for the record.

• Queue.lockLife, default 30. Minutes to keep lockfiles.

• Queue.completedLife, default 30. Days to keep completed tasks.

UI using Houston:admin (Optional)

"Houston is a zero-config Meteor Admin, modeled after Django Admin, intended as a simple way for developers to give end-users (or themselves) an easy way to view and manipulate their app's data."" https://github.com/gterrono/houston

Houston can be used for CRUD of queued jobs and setInterval tasks. It can also be used for viewing/purging logs.

All you need is to install houston

meteor add houston:admin

A "Run Now" button will appear above all queue entries. Also a "Stop" button will appear on all queueInterval tasks. All queueinterval changes will change the task via Meteor's setInterval method.

Examples

if (Meteor.isServer) {
  Meteor.startup(function () {
   Queue.loglevel = 1;
	Queue.keepsuccess = true;
	// code to run on server at startup
	Queue.add({command:'console.log("queue called now");'});
	Queue.add({command:'console.log("last queue called");',priority:10});
	Queue.add({command:'console.log("queue called again");'});
	Queue.add({command:'console.log("first queue called");',priority:1});
	console.log('about to run queue');
	Queue.run();
	console.log('done with the first run');
	future = new Date();
	future.setMinutes(future.getMinutes() + 1);
	Queue.add({command:'console.log("queue called in THE FUTURE");',execute_after:future});
	future.setMinutes(future.getMinutes() + 1);
	Queue.add({command:'console.log("THE FUTURE a bit later");',execute_after:future});

    Queue.changeMainInterval(15000); /*changes queue processing interval to 15sec (default 5 sec)*/

    /* set maintenance tasks */
    Queue.setInterval('purgeLocks', 'Queue.purgeOldLocks', 60000); /* once a minute */
    Queue.setInterval('purgeCompleted', 'Queue.purgeCompletedTasks()', 86400000); /* once a day */
    Queue.setInterval('purgeLogs','Queue.purgeOldLogs()', 86400000); /* once a day */

}

TODO

• Documentation improvements
• More thorough testing
• consider UI improvements