timed-queue

timed-queue

Distributed timed job queue, backed by redis.

Features

• Support redis cluster.
• Support one or more timed-queue instance in a redis instance. Each timed-queue instance are segregated by prefix option
• Support one or more job queues in a timed-queue instance.
• Support one or more timed-queue clients for a timed-queue instance.

Demo

const TimedQueue = require('timed-queue')
const timedQueue = new TimedQueue({prefix: 'TQ1', interval: 1000 * 60})


// connect to redis cluster.
timedQueue.connect([7000, 7001, 7002])
  .on('error', function (error) {
    console.error(error)
  })


// create 'event' job queue in timed-queue instance
const eventQueue = timedQueue.queue('event')

// add 'job' listener
eventQueue.on('job', function (jobObj) {
  // ... just do some thing
  // ACK the job
  eventQueue.ackjob(jobObj.job)()
})

// add job to queue
eventQueue.addjob(eventObj.id, new Date(eventObj.startDate).getTime() - 10 * 60 * 1000)(function (err, res) {
  console.log(err, res)
})

Installation

npm install timed-queue

Job

Job Class:

function Job (queue, job, timing, active, retryCount) {
  this.queue = queue
  this.job = job
  this.timing = timing
  this.active = active
  this.retryCount = retryCount
}

• this.queue: {String} Queue name
• this.job: {String} The job's name
• this.timing: {Number} The time in millisecond when the job should be actived
• this.active: {Number} The actual time in millisecond that the job be actived
• this.retryCount: {Number} A job that has been actived but has not been ACK in retry time will be actived again. retryCount is times that the job re-actived.

API

const TimedQueue = require('timed-queue')

new TimedQueue([options]) => timedQueue object

Return a timedQueue client. It is an EventEmitter instance.

• options.prefix: {String} Redis key's prefix, or namespace. Default to "TIMEDQ"
• options.count: {Number} The maximum job count for queue's getjobs method. Default to 64
• options.interval: {Number} Interval time for scanning. Default to 1000 * 60 ms
• options.retry: {Number} Retry time for a job. A job that has been actived but has not been ACK in retry time will be actived again. Default to interval / 2 ms
• options.expire: {Number} Expiration time for a job. A job that has been actived and has not been ACK in expire time will be removed from the queue. Default to interval * 5 ms
• options.accuracy: {Number} Scanning accuracy. Default to interval / 5
• options.autoScan: {Boolean} The flag to enable or disable automatic scan. Default to true. It can be set to false if automatic scan is not desired.

const timedQueue = new TimedQueue()

TimedQueue Events

• timedQueue.on('connect', function () {})
• timedQueue.on('error', function (error) {})
• timedQueue.on('close', function () {})
• timedQueue.on('scanStart', function (queuesLength) {})
• timedQueue.on('scanEnd', function (queuesLength, timeConsuming) {})

TimedQueue.prototype.connect([host, options]) => this

TimedQueue.prototype.connect(redisClient) => this

Connect to redis. Arguments are the same as thunk-redis's createClient, or give a thunk-redis instance.

timedQueue.connect()

TimedQueue.prototype.scan() => this

Start scanning. It automatically starts after connect method is called unless autoScan is set to false.

TimedQueue.prototype.stop() => this

Stop scanning.

TimedQueue.prototype.close() => this

Close the timedQueue. It closes redis client of the timedQueue accordingly.

TimedQueue.prototype.regulateFreq(factor) => this

It is used to regulate the automatic scanning frequency.

TimedQueue.prototype.destroyQueue(queue[, options]) => this

Remove the queue. It deletes all data in the queue from redis.

TimedQueue.prototype.queue(queue[, options]) => Queue instance

Return a Queue instance if one exists. Otherwise it creates a Queue instance and return it. Queue instance is a EventEmitter instance.

• queue: {String} The queue's name
• options.count: {Number} The maximum job count for queue's getjobs method. Default to timedQueue's count
• options.retry: {Number} Retry time for a job. A job that has been actived and has not been ACK in retry time will be actived again. Default to timedQueue's retry
• options.expire: {Number} Expiration time for job. A job that has been actived and has not been ACK in expire time will be removed from the queue. Default to timedQueue's expire
• options.accuracy: {Number} Scanning accuracy, Default to timedQueue's accuracy

const eventQueue = timedQueue.queue('event', {retry: 1000, expire: 5000})

Queue Events

• queue.on('job', function (job) {})

If no job listener on queue, queue scanning will not run.

Queue.prototype.init([options]) => this

• options.count: {Number} The maximum job count for queue's getjobs method. Default to timedQueue's count
• options.retry: {Number} Retry time for a job. A job that has been actived and has not been ACK in retry time will be actived again. Default to timedQueue's retry
• options.expire: {Number} Expire time for a job. A job that has been actived and has not been ACK in expire time will be removed from queue. Default to timedQueue's expire
• options.accuracy: {Number} Scanning accuracy. Default to timedQueue's accuracy

Queue.prototype.addjob(job, timing[, job, timing, ...]) => thunk function

Queue.prototype.addjob([job, timing, job, timing, ...]) => thunk function

Add one or more jobs to the queue. It can be used to update the job's timing.

• job: {String} The job's name
• timing: {Number} The time in millisecond when the job should be actived. It should greater than Date.now()

eventQueue.addjob('52b3b5f49c2238313600015d', 1441552050409)(function (err, res) {
  console.log(err, res)
  // null, 1
})

Queue.prototype.show(job) => thunk function

Show the job info.

• job: {String} job

eventQueue.show('52b3b5f49c2238313600015d')(function (err, res) {
  console.log(err, res)
  // {
  //   queue: 'event',
  //   job: '52b3b5f49c2238313600015d',
  //   timing: 1441552050409
  //   active: 0,
  //   retryCount: 0
  // }
})

Queue.prototype.deljob(job[, job, ...]) => thunk function

Queue.prototype.deljob([job, job, ...]) => thunk function

Delete one or more jobs.

• job: {String} job

eventQueue.deljob('52b3b5f49c2238313600015d')(function (err, res) {
  console.log(err, res) // null, 1
})

Queue.prototype.getjobs([scanActive]) => thunk function

It is called by Queue.prototype.scan. It should not be called explicitly unless you know what you are doing.

Queue.prototype.ackjob(job[, job, ...]) => thunk function

Queue.prototype.ackjob([job, job, ...]) => thunk function

ACK one or more jobs.

• job: {String} job

eventQueue.ackjob('52b3b5f49c2238313600015d')(function (err, res) {
  console.log(err, res) // null, 1
})

Queue.prototype.scan() => thunk function

It is called by TimedQueue.prototype.scan. It should not be called explicitly unless you know what you are doing.

Queue.prototype.len() => thunk function

Return the queue' length.

eventQueue.len()(function (err, res) {
  console.log(err, res) // null, 3
})

Queue.prototype.showActive() => thunk function

Return actived jobs in the queue.

eventQueue.showActive()(function (err, res) {
  console.log(err, res) // null, [jobs...]
})