The asp.net core application loads the CPU even after a user requests are terminated.

[neyromant]

Hi,
My asp.net core application is builded on .net core 2.1 and launched under CentOS 7.4 (Outside the Docker container).
During the working day, this application has a high load. At night, when requests from clients stop, the application continues to use a lot of CPU. This stops only if I restart the application.

I searched for the blocking code manually and using Ben.BlockingDetector. (Question about this here: benaadams/Ben.BlockingDetector#9) But I did not find anything.

I collected and tried to analyze metrics using perfcollect

These metrics are taken at night, when there are no requests from clients, but the application uses 206% of the CPU (The machine has 4 cores):

My metrics are available here: (my application's name is current_app.anm)
https://drive.google.com/open?id=1SHTJqfWUMMOECcDUKnz37st1r4u_P4-j

Can anyone tell me what could be causing this problem?
Thank you in advance for any response.

[Eilon]

@sebastienros - thoughts?

[neyromant]

I thought that it depends on bug in System.IO.Pipelines package like issue in Kestrel
But after connecting the package <PackageReference Include="System.IO.Pipelines" Version="4.5.1" /> to my project nothing has changed.

dotnet/announcements#83
aspnet/KestrelHttpServer#2694

[davidfowl]

@neyromant Did you update to .net core 2.1.4?

[neyromant]

@davidfowl Not yet, I just updated System.IO.Pipelines package.
My application is Self Contained Application and I do not use Microsoft.AspNetCore.App.
Maybe the problem is this?

[Eilon]

@sebastienros any ideas on how to diagnose this?

[gzpbx]

@neyromant The same problem with yours - even no any request the asp.net core application still load high CPU, aspnet/KestrelHttpServer#2937

[sebastienros]

It could be the finalizer thread that is getting blocked. It would run even without any requests.

• Are you using EntityFramework, and changing how it's tracing SQL?
• Are you using HttpClient to request external services?

[davidfowl]

Can you take a memory dump? That might help as you can look at the finalizer queue that way.

[neyromant]

• Are you using EntityFramework, and changing how it's tracing SQL?
• Are you using HttpClient to request external services?

Yes

[neyromant]

Can you take a memory dump? That might help as you can look at the finalizer queue that way.

Yes, of cource. My dump is here:
https://drive.google.com/file/d/1GPDSDktxOL_Cma61ZKSw3NH4gyhYnkr5/view?usp=sharing

[davidfowl]

Is this gcore dump or did you use https://github.com/dotnet/coreclr/blob/21f94f2be12e16bb36187d40c2fa82af9ebfd469/Documentation/botr/xplat-minidump-generation.md?

[neyromant]

This is gcore dump:

# ulimit -c unlimited 
# sudo gcore -o dump1 <pid of my self contained app>

[davidfowl]

Yep, I figured from the size 😄. This was collected on CentOS 7.4 yeah?

[neyromant]

This was collected on CentOS 7.4 yeah?

Yep, it is CentOS 7.4

[davidfowl]

I can't get this dump to load properly:

Try “readelf -a dump1.17928” and you will get some error messages:

readelf: Error: Reading 0x18c00 bytes extends past end of file for section headers
readelf: Error: Section headers are not available

[neyromant]

I'm sorry. I will check or I will soon make a new dump.

[neyromant]

@davidfowl, I am sorry for long answer.
I have uploaded corrected and checked dump here: https://drive.google.com/file/d/1ErM5in4N7ED620QWNHtW2abKFua1PtnN/view?usp=sharing

[mmikirtumov]

We have the same issue and we use HttpClient.
This problem occured when we update to .Net Core 2.1.4.
For HttpClient we created wrapper class, which is scoped and constructor have only one line of code
_httpClient = new HttpClient();
Do you have any idea what is the problem?

[poke]

@mmikirtumov Please consider using the HttpClientFactory for that. It will automatically follow the best practices when working with a HttpClient.

[mmikirtumov]

Thank you Patrick. I know that this is good practice. I am trying to figure it out what is the problem currently in my production server. And can HttpClient cause this issue?

[neyromant]

We are use the HttpClientFactory.

[vmayushan]

We are use the HttpClientFactory.

@neyromant
Have you resolved your issue? We have the same problem and now we are using HttpClientFactory.

We took a trace, but it didn't help us.

[neyromant]

@Vlad294 Unfortunately no

[ghost]

Thank you for contacting us. Due to a lack of activity on this discussion issue we're closing it in an effort to keep our backlog clean. If you believe there is a concern related to the ASP.NET Core framework, which hasn't been addressed yet, please file a new issue.

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