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nsq.js-k8

1.2.0 • Public • Published

Build Status

nsq.js

JavaScript NSQ client WIP.

Features

  • actually written in js :p
  • easier debugging via debug() instrumentation
  • native json message support
  • does not arbitrarily apply backoff on requeues
  • disabling of auto-RDY support for manual control (high throughput etc)
  • reconnection to dead nsqd nodes
  • graceful close support

Installation

$ npm install nsq.js

About

Debugging

The DEBUG environment variable can be used to enable traces within the module, for example all nsq debug() calls except fo the framer:

$ DEBUG=nsq*,-nsq:framer node test

nsq:reader connect nsqd 0.0.0.0:4150 events/ingestion [5] +0ms
nsq:connection connect: 0.0.0.0:4150 V2 +0ms
nsq:connection command: IDENTIFY null +2ms
nsq:connection command: SUB ["events","ingestion"] +1ms
nsq:connection command: RDY [5] +0ms
nsq:connection connect: undefined:4150 V2 +0ms
nsq:connection command: IDENTIFY null +1ms
nsq:connection command: PUB ["events"] +0ms
nsq:reconnect reset backoff +0ms
nsq:reconnect reset backoff +1ms
nsq:connection response OK +3ms
nsq:connection response OK +0ms
nsq:connection response OK +0ms

Requeue backoff

The NSQD documentation recommends applying backoff when requeueing implying that the consumer is faulty, IMO this is a weird default, and the opposite of what we need so it's not applied in this client.

Example

var nsq = require('nsq.js');
 
// subscribe
 
var reader = nsq.reader({
  nsqd: [':4150'],
  maxInFlight: 1,
  maxAttempts: 5,
  topic: 'events',
  channel: 'ingestion'
});
 
reader.on('error', function(err){
  console.log(err.stack);
});
 
reader.on('message', function(msg){
  var body = msg.body.toString();
  console.log('%s attempts=%s', body, msg.attempts);
  msg.requeue(2000);
});
 
reader.on('discard', function(msg){
  var body = msg.body.toString();
  console.log('giving up on %s', body);
  msg.finish();
});
 
// publish
 
var writer = nsq.writer(':4150');
 
writer.on('ready', function() {
  writer.publish('events', 'foo');
  writer.publish('events', 'bar');
  writer.publish('events', 'baz');
});

API

nsq.reader(options)

Create a reader:

  • id connection identifier (see client_id in the spec)
  • topic topic name
  • channel channel name
  • nsqd array of nsqd addresses
  • nsqlookupd array of nsqlookupd addresses
  • maxAttempts max attempts before discarding [Infinity]
  • maxConnectionAttempts max reconnection attempts [Infinity]
  • maxInFlight max messages distributed across connections [10]
  • msgTimeout session-specific msg timeout
  • pollInterval nsqlookupd poll interval[10000]
  • ready when false auto-RDY maintenance will be disabled
  • trace trace function

Events:

  • message (msg) incoming message
  • discard (msg) discarded message
  • error response (err) response from nsq
  • error (err)

reader#close([fn])

Close the reader's connection(s) and fire the optional [fn] when completed.

nsq.writer([options|address])

Create a writer. By default a connection attempt to 0.0.0.0:4150 will be made unless one of the following options are provided:

  • port number
  • host name
  • nsqd array of nsqd addresses
  • nsqlookupd array of nsqlookupd addresses

Events:

  • error response (err) response from nsq
  • error (err)

writer#publish(topic, message, [fn])

Publish the given message to topic where message may be a string, buffer, or object. An array of messages may be passed, in which case a MPUT is performed.

writer#close([fn])

Close the writer's connection(s) and fire the optional [fn] when completed.

Message

A single message.

Message#finish()

Mark message as complete.

Message#requeue([delay])

Re-queue the message immediately, or with the given delay in milliseconds, or a string such as "5s", "10m" etc.

Message#touch()

Reset the message's timeout, increasing the length of time before NSQD considers it timed out.

Message#json()

Return parsed JSON object.

Tracing

The following jstrace probes are available:

  • connection:ready ready count sent
  • connection:message message received
  • message:finish finished a message
  • message:requeue requeued a message
  • message:touch touched a message

Running tests

nsqd --lookupd-tcp-address=0.0.0.0:4160 --broadcast-address=localhost &
nsqadmin --lookupd-http-address=0.0.0.0:4161 &
nsqlookupd --broadcast-address=localhost &
make test

License

MIT

Install

npm i nsq.js-k8

DownloadsWeekly Downloads

8

Version

1.2.0

License

MIT

Unpacked Size

45.1 kB

Total Files

15

Last publish

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