mongoose-jobqueue
v1.1.3
Published
Simple Job-Queue using mongoosejs
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mongoose-jobqueue
A very simple job queue, using mongoosejs for storage.
Quickstart
Create a queue object by handing over your mongoose instance:
var mongoose = require('mongoose');
var mongooseJobQueue = require('mongoose-jobqueue');
var queue = mongooseJobQueue(mongoose, 'job-queue');
All functions of the queue return a Promise
.
See bluebirdjs.com for more information on promises.
Add a job to a queue:
queue.add({ message: 'Hey' }).then(function(job){
// Job with payload object added.
// The created job-object is returned.
}, function(err){
// Something went wrong!
});
Get a job from the queue:
queue.checkout().then(function(job) {
// Returns the next job in the queue, or null if queue is empty.
console.log('job._id=' + job._id);
console.log('job.ack=' + job.ack); // Acknowledge key, save for later
console.log('job.payload=' + job.payload); // { message: 'Hey' }
console.log('job.tries=' + job.tries);
});
Ping a job to keep it's visibility open for long-running tasks:
queue.ping(job.ack).then(function(job) {
// Visibility window now increased for this job.
// Updated job object is returned.
})
When pinging a job we can specify by how many seconds the window is extended, and the progress of the job in percent if we want:
queue.ping(job.ack, 60, 15).then(function(job) {
// Visibility window now increased by 60 seconds. Job is 15% done.
// Updated job object is returned.
})
Acknowledge a job (and remove it from the queue):
queue.ack(job.ack).then(function(job) {
// This job removed from queue for this ack.
// The acknowledged job is returned.
})
By default, all finished jobs are left in the queue, and are only marked as deleted. You can call the following function to remove processed jobs:
queue.cleanup().then(function(delCount) {
// All processed (ie. acked) messages have been deleted
// The number of deleted jobs is returned.
});
In-Code-Docs
The source code is documented using JSDoc tags.
You can build the documentation as HTML files to /docs/build
by using:
npm install
npm run jsdoc
Creating a Queue
To create a queue, call the exported function with the Mongoose instance, the name of the collection and a set of options.
var mongoose = require('mongoose');
var mongooseJobQueue = require('mongoose-jobqueue');
// an instance of a queue
var queueA = mongooseJobQueue(mongoose, 'a-queue');
// another queue
var queueB = mongoDbQueue(mongoose, 'b-queue');
Note: You can start using the queue right away, since mongoose stores requests until a connection to the MongoDB is established.
To pass in options for the queue:
var myQueue = mongooseJobQueue(mongoose, 'my-queue', {
visibility : 30,
delay : 15
});
This example shows a queue with a job visibility of 30s and a insert-delay of 15s.
Options
name - Collection Name
This is the name of the MongoDB Collection you wish to use to store the jobs. Each queue you create will be it's own collection.
e.g.
var queueA = mongooseJobQueue(mongoose, 'a-queue');
var queueB = mongooseJobQueue(mongoose, 'b-queue');
This will create two collections in MongoDB called a-queue
and b-queue
.
visibility - Job Visibility Window
Default: 30
By default, if you don't ack a job within the first 30s after checking it out of the queue, it is placed back in the queue so it can be fetched again. This is called the visibility window.
You may set this visibility window on a per queue basis. For example, to set the visibility to 15 seconds:
var queue = mongooseJobQueue(mongoose, 'queue', { visibility : 15 });
All jobs in this queue now have a visibility window of 15s, instead of the default 30s.
You can also specify the visibility window when checking out a job of the queue:
var queue = mongooseJobQueue(mongoose, 'queue', { visibility : 15 });
queue.checkout(90).then(function(job){
// Process the job...
});
The returned job now has a visibility window of 90s. This does not change the visibility window of the queue or other jobs in the queue.
delay - Delay Jobs on Queue
Default: 0
When a job is added to a queue, it is immediately available for checkout.
However, there are times when you might like to delay jobs coming off a queue.
If you set delay to be 10
, then every job will only be available for
checkout 10s after being added.
To delay all jobs by 10 seconds, do this:
var queue = mongooseJobQueue(mongoose, 'queue', { delay : 10 });
This is now the default for every job added to the queue.
deadQueue - Dead Job Queue
Default: null
Jobs that have been retried over maxRetries
will be pushed to this queue so
you can debug problematic jobs.
Pass in a collection name onto which these jobs will be pushed:
var queue = mongooseJobQueue(mongoose, 'queue', { deadQueue : 'dead-jobs' });
If you checkout a job out of the queue
over maxRetries
times and have still
not acked it, it will be pushed onto the deadQueue
for you.
This happens when you call .checkout()
the next time. (not when you miss
acking a job within it's visibility window).
maxRetries - Maximum Retries per Job
Default: 5
This option only comes into effect if you pass in a deadQueue
as shown above.
What this means is that if job is checked out of the queue maxRetries
times
(e.g. 5) and not acked, it will be moved to the deadQueue
the next time it is
checked out.
strictAck - Disallow ack if Visibility Window timed out
Default: true
By default you are only allowed to acknowledge a checked out job within the
visibility window. Set this option to false
if you want to allow acks of a job
outside of the visibility window, given that the job was not already checked out
a second time by another user.
raw - Return raw JavaScript Objects
Default: true
By default all functions return plain JavaScript objects. Set this option to
false
if you want the original mongoose documents returned. For example, this
gives you the ability to edit a returned job and call the .save()
method on in.
Use this option at own risk.
cosmosDb - Use compatibility mode for Azure CosmosDB
Default: false
CosmosDB does not support sorting on a findAndUpdate operation. (as of 2017-08-22)
Set this option to true
to get unsorted results.
Operations
.add()
You can add a string to the queue:
queue.add('Hey').then(function(job) {
// Job with payload 'Hey' added.
// Created job object is returned.
});
Or add an object:
queue.add({ message: 'Hey' }).then(function(job) {
// Job with payload { message: 'Hey' } added.
// Created job object is returned.
});
Or add multiple jobs (strings or objects):
queue.add(['One', 'Two', 'Three']).then(function(jobs) {
// Jobs with payloads 'One', 'Two' & 'Three' added.
// An array of the created job objects is returned.
});
You can delay jobs from being visible by passing the second delay
parameter:
queue.add('Later', 120).then(function(job) {
// Job with payload 'Later' added.
// Created job object is returned.
// This job won't be available for checkout for 120 seconds.
});
.checkout()
Retrieve a job from the queue:
queue.checkout().then(function(job) {
// You can now process the job
// IMPORTANT: The message will be null if the queue is empty.
});
You can choose the visibility window of an individual retrieved job by passing
the visibility
parameter:
queue.checkout(90).then(function(job) {
// You can now process the job for 90s before it goes back into the queue.
});
Jobs will have the following structure:
{
_id: '533b1eb64ee78a57664cc76c', // ID of the message
ack: 'c8a3cc585cbaaacf549d746d7db72f69', // Key for ack and ping operations
payload: 'Hey', // Payload passed when the job was addded
tries: 1 // Number of times this job has been retrieved from queue without being ack'd
}
.ack()
After you have received a job from a queue and processed it, you can delete it
by calling .ack()
with the unique ack
key returned:
queue.checkout().then(function(job) {
// Do some processing...
queue.ack(job.ack).then(function(job) {
// this job has now been removed from the queue
});
});
.ping()
After you have checked out a job from a queue and you are taking a while
to process it, you can .ping()
the job to tell the queue that you are
still alive and continuing to process the job:
queue.checkout().then(function(job) {
queue.ping(job.ack).then(function(job) {
// this job has had it's visibility window extended
});
});
You can also choose the visibility time that gets added by the ping operation by
passing the visibility
parameter:
queue.checkout().then(function(job) {
queue.ping(job.ack, 120).then(function(job) {
// this job has had it's visibility window extended by 120 seconds
});
});
You can pass an optional progress
parameter, when pinging a job to show the
progress of your operation in percent:
queue.checkout().then(function(job) {
queue.ping(job.ack, 120, 12).then(function(job) {
// this job has had it's visibility window extended by 120 seconds
// The operation is completed by 12%
});
});
Like the progress
parameter you can pass the payload
parameter to update the
payload of a job. This will overwrite the old payload value.
queue.checkout().then(function(job) {
queue.ping(job.ack, null, null, { message: 'my new payload' }).then(function(job) {
// Updated job object is returned.
});
});
.get()
Get a list of jobs in the queue. Does not check out any jobs.
queue.get().then(function(jobs){
// Returns an array of all jobs in queue, processed or not
});
You can pass a filter object to only retrieve a subset of jobs. The filter object follows the MongoDB query syntax.
queue.get({
deleted: null
}).then(function(jobs){
// Returns an array of all that are not processed
});
This example returns only unfinished jobs.
queue.get({
tries: { $gt: 1, $lt: 4 }
}).then(function(jobs){
});
This example returns jobs with 2-3 tries.
queue.get({
'payload.message': 'Hey'
}).then(function(jobs){
});
This example returns jobs where the payload contains the message Hey
.
.cleanup()
By default, all finished jobs are left in the queue, and are only marked as
deleted. You can call the cleanup()
function to remove processed jobs:
queue.cleanup().then(function(delCount) {
// All processed (ie. acked) jobs have been deleted.
// The number of deleted jobs is returned.
});
You can specify the minimum age of jobs to be deleted by using the age
parameter:
queue.cleanup(120).then(function(delCount) {
// All processed (ie. acked) jobs older than 120 seconds have been deleted.
// The number of deleted jobs is returned.
});
.cleanupDead()
Removes all jobs from the deadQueue.
Unlike the cleanup()
function, this operation does not have a age parameter.
queue.cleanupDead().then(function(delCount) {
// All dead jobs have been deleted.
// The number of deleted jobs is returned.
});
.reset()
Deletes ALL jobs from the queue (and the deadQueue if configured), regardless of checked out jobs.
queue.reset().then(function(totalDeleted) {
// Queues are now empty, number of deleted jobs on both queues is returned.
});
Releases
1.1.3 (2017-12-06)
- [FIX] Minor fix for use with "multi-connection" mongoose instances
1.1.2 (2017-08-22)
- [NEW] Added option for Azure CosmosDB (Azure CosmosDB does not support sorting on findAndUpdate)
1.1.1 (2017-08-21)
- [FIX] Fixed null error on checkout.
1.1.0 (2017-08-15)
- [NEW] Added option to update payload on ping.
- [NEW] Added option to return the original mongoose documents instead of plain JavaScript objects.
1.0.1 (2017-08-06)
- [NEW] Documentation & Readme Update
- [FIX] Ack function now correctly rejects if the visibility window timed out.
- [FIX] Add function now returns job object if one job was added, or array of objects if multiple jobs were added.
1.0.0 (2017-08-05)
- Initial Release
Author
Written by Michael Sperk
License
MIT - https://choosealicense.com/licenses/mit/