High CPU usage on macOS

[ajitam]

Hello,

I've been using Mosca for some time know on different ENVs (macOS and Ubuntu). Last week I formatted my Macbook Pro and now whenever I ran nodejs script with Mosca inside node task in Activity monitor start burning 50% and more of CPU.

Is there any why I can somehow debug this?

Here is what I know:

• macOS 10.12.1
• node version 6.9.1 (installed over NVM), I also tried with 4.6.0 bd 5.12.0
• I tried restart the computer
• for testing I have empty folder where I install Mosca (npm install mosca) and index.js with a simple script from the readme file ☛ index.js
• I notices that when I install mosca I get some errors around instaling zmq

thx, matija

[ajitam]

Ok, I might have found some more leads around this problem.

• I ran script on another mac (node version 5.4.1) and I notice that on both systems - if I turn OFF mongoDB backend script runs 0K
• some older scripts on (nodejs 5.4.1) mac were running 0K too but I didn't know why

After some additional research I noticed that - if I ran the script with DB which already existed everything was 0K, but if I started script with new DB CPU usage got hight again. So naturally on newly formatted mac I didn't had any old DBs.

So bottom line: If I start mosca with backend using mongoDB (and use new DB name) CPU usage is hight (DB is created)

[mcollina]

@ajitam interesting. Is the CPU staying high, or does it lower after a while? Maybe there is a bug somewhere in the collection-creation logic. Would you like to try a PR? The problem is likely to be in https://github.com/mcollina/ascoltatori

[ajitam]

1. As far as I can tell script is running on high CPU non-stop (I think I was running it for at least 2 hours)
2. I can confirm the same behaviour on Ubuntu 16.04.1 LTS
3. Regarding PR - frankly I'm not filling qualified for the task :/

p.s.: for now I have very dirty fix - I export mqtt DB from the server and import it into my local mongoDB