My server has constaly 40% CPU usage.... Even when there are NO requests.

I'm searching "wtf is going on" for the past 2 days.

0 results. Clients are unhappy, sales team is unhappy. Noone is happy and I don't have an answer. Grrrrrrr.

*Goes back to reading logs

By server I mean Azure WebApp, not a VM/ohysical server

What stack?

@spongessuck

.net 4.7 mixed with Azure functions with .nbet core, on the same service plan.

Have you isolated the offending app?

@spongessuck Yes and no. There is only 1 webapp running (And 1 staging slot).

Cutting azure functions doesn't change a thing. Can't cut webapp as it's in production (But will do this night for testing)

Edit : yes it is a web app. I stopped staging, republished on staging, swaped them, stopped new staging : CPU Usage 1%.

Do I have infinite loop somewhere ? :(

So it's not the function I guess.

As for the net47 app, what prod work is it doing if there aren't any requests?

Or it is getting requests just not all the time.

@spongessuck None.

It's pretty SQL heavy app, but if there are no requests it's not supposed to do a thing. And most of heavy lifting is done by Azure functions (App ships a message in a queue and function pick it up).

Ok, soooo now I have ice 1% usage 9I guess timed Azure functions). here are stats (users are asleep lol, the few requests you see I generated).

(Note CPU scale is by core, not toal of 4xcores)

@spongessuck really feels like we have infinite loop somewhere :(

No idea how to track it YET !

Idk looks like responses are pretty fast.

That's more like 25% load isn't it?

@spongessuck Hmmmm

I think there is an issue with "slow" sql calls. I'll start checking it.

my self with only 10 tabs open (On the slowest page of the app tho), I managed to put cpu at 100% (so 400% on screen )

Bizzare thing is memory drop to 0, is it rebooting lol?

Thanks for debug assistance tho ! Pushed me to do some unusual tests

Some asynchronous call thats not shutting down properly? Or leaving connections/sockets/services running during the call?

@lynkfox It doesn't use direct sockets or anything. ONE thing I should check is a 3d party lib (Link with billing system). Maybe something there

Azure ? oh .....

Any schedulers/cron jobs running inside the app and hitting the databse or something?

Check all "db change"/"db inspection" observers.
This might be caused by a change to Table A, triggering observer 1, that makes a change to table B, trigerring Observer 2, that makes a change to table A - and completing a circle.

3rd party libs are usualy not the cause - unless you are using it wrong.

Ahh the ol' good one while loop performance improvement :D?

While(true){
Thread.sleep(4000); //lower this number when performance improvement needs to be done

}