moleculer: metrics make request 10x times slower

The issue scenario is : apiGateway.rest -> auth.authorize->demo.welcome->demo.hello every step is very simple, should only consider network cost.

If i enable metrics: true in each services process, use about 120ms total. Buf if i disable metrics, it only use about 10ms.

metrics internal use event broadcast ? Then is should not impact normal performance so badly.

About this issue

Original URL
State: closed
Created 6 years ago
Comments: 39 (37 by maintainers)

Commits related to this issue

add nats noDelay workaround #313 — committed to moleculerjs/moleculer by icebob 6 years ago

Most upvoted comments

After long time digging and testing, i found the reason. I don’t know its NATS or Nodejs bug. The Nodejs said noDelay defaults to true, but its not.

socket.setNoDelay([noDelay]) Disables the Nagle algorithm. By default TCP connections use the Nagle algorithm, they buffer data before sending it off. Setting true for noDelay will immediately fire off data each time socket.write() is called. noDelay defaults to true.

Just modify this file at: node_modules/nats/lib/nats.js

// Create the stream
    this.stream = net.createConnection(this.url.port, this.url.hostname);
    this.stream.setNoDelay(true)  // need call it, somehow default 'true' is not work

After manually add setNoDelay(true), it works fine on ubuntu:

call demo1.hello1 at:  1530870151475
call demo2.hello2 at:  1530870151477
call demo3.hello3 at:  1530870151478
call demo1.hello1 use time =  8
call demo1.hello1WithEvent startTime =  1530870151480
call demo1.hello1WithEvent at:  1530870151481
listen e1 at:  1530870151482
call demo2.hello2WithEvent at:  1530870151483
listen e2 at:  1530870151484
call demo3.hello3WithEvent at:  1530870151484
listen e3 at:  1530870151485
call demo1.hello1WithEvent endTime =  1530870151486
call demo1.hello1WithEvent use time =  6

test environment:

moleculer: 0.12.8
nodejs: 8.11.1
node-nats: 1.0.0
gnatsd: 1.2.0
system: ubuntu 16.04 server

roytan883 on Jul 6, 2018

npm already has a fix for this, you may want to just update and remove the patching.

aricart on Jul 17, 2018

OK, i will create a dev example file

roytan883 on Jul 3, 2018