q3-core-scheduler
v4.5.16
Published
For handling background processes in your application use Q3 Scheduler. We recommended running the scheduler on an independent server since it uses MongoDB as a persistence layer. This way, your web requests and your jobs don't need to compete for res
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Scheduler
For handling background processes in your application use Q3 Scheduler. We recommended running the scheduler on an independent server since it uses MongoDB as a persistence layer. This way, your web requests and your jobs don't need to compete for resources.
Scheduler.queue
To add one-time jobs, call the queue
method. It takes two
arguments: the name and the payload (optional). The payload
can contain any data, though it will process the buckets
and session
properties differently.
If the payload contains buckets
, the receiving function
will have file attachments in its second parameter position.
Likewise, if the payload contains session
, it will hydrate
the q3-core-session
module before executing the file.
const Scheduler = require('q3-core-scheduler');
Scheduler.queue('file', {
buckets: [],
session: {},
id: 1,
}).then(() => {
// will eventually call the file below at chores/file.js
});
module.exports = (data, attachments) => {
console.log('Regular data:', data);
console.log('File buffers:', attachments);
};
Scheduler.seed
When the scheduler receives a target directory, it will walk
the files in it looking for recurring jobs. Recurring jobs
have files ending in @${interval}.js
. Acceptable interval
values include annually
, biannually
, quarterly
,
monthly
, weekly
, daily
, bihourly
, hourly
,
semihourly
, biminutely
and minutely
.
const Scheduler = require('q3-core-scheduler');
// tells the scheduler to look for jobs in this directory
Scheduler.seed(__dirname).then(() => {
console.log('Recurring jobs saved');
});
Scheduler.start
Given an executable directory and an interval, the queue manager can run. It will work by priority sequence (high to low) and lock any jobs in progress, processing just one at a time. After execution, the queue manager will stamp a completition date (iso) and duration (ms) for benchmarking and debugging purposes.
const Scheduler = require('q3-core-scheduler');
// tells the scheduler to execute files in this directory
// every 10 milliseconds
Scheduler.start(__dirname, 10).then(() => {
console.log('Queue manager started');
});
Events
Scheduler implements a custom EventEmitter
and exposes its
on
listener publicly. During the queueing process, each
job will emit two of three events.
Scheduler.on("start")
: Every job emits this event before it executes;Scheduler.on("finish")
: Successful jobs emit this event before the queue starts to look for the next job;Scheduler.on("stall")
: Failed jobs emit this when an error occurs during execution.
Alternatively, when a new job gets added, the emitter will
fire the queued
event.