[Mono-list] mod-mono-server process busy 100% or 200% CPU

[Maxim]

Hi William!

I've optimized slow queries, and it seems like there is no relation between 
db-server response time and this situation.
Today mod-mono-server jumped to 100% cpu consumption several times, but from 
MySQL-server side all the queries was faster than 0.3 sec (I'm monitoring "long 
queries").

I'll try to update mono to 2.3.8.

By the way, seems like mod_mono and xsp projects has no updates since 2011 year.

Regards,
Max Karavaev

On 09/04/2014 07:01 AM, William Ivanski wrote:
> Hi Max,
>
> Same version as you, 3.2.8, also using SGEN. But not compiled from sources, installed from Debian repositories.
>
>
>
> Em qui 04 set 2014 06:07:00 você escreveu:
>> Hi William!
>>
>> My situation looks like the same. MySQL backend of website sometimes response
>> too slow.
>> I've reduced all timeouts and it helps a little.
>> The difference - I'm using xsp2.
>>
>> By the way, what version of Mono do you use?
>>
>> Regards,
>> Max Karavaev
>>
>>
>> On 09/03/2014 11:58 PM, William Ivanski wrote:
>>> We also ran into this problem here.
>>>
>>> I never could really track which was the cause of the CPU overload. BUT...
>>>
>>> Our XSP4 process access an Oracle XE database. At the time of the 100% - 200%
>>> CPU overload, the Oracle processes were processing some stuff, and the memory
>>> and swap usage of the Oracle processes was high too.
>>>
>>> Memory usage of the XSP4 processes was normal.
>>>
>>> So, I might guess the Oracle processes "hanged" or found a "deadlock", and
>>> somehow the XSP4 overload the processor when it cannot get immediate response
>>> from the Oracle server.
>>>
>>> William Ivanski
>>>
>>>
>>> 2014-09-03 10:03 GMT-03:00 Maxim <makska at yandex.ru <mailto:makska at yandex.ru>>:
>>>
>>>      Hello!
>>>
>>>      I've just created ASP.Net website and ran it on Apache&mono on Linux.
>>>      And I've got strange situation. After 50.000-100.000 requests
>>>      mod-mono-server process unexpectedly become busy with 100% or 200%
>>>      (exactly) CPU load.
>>>      After restarting mono process via mono-ctl panel cpu consumption returns
>>>      to 1-3%.
>>>      I've found some errors like
>>>      [Wed Sep 03 16:02:57 2014] [error] (32)Broken pipe: write_data failed
>>>      [Wed Sep 03 16:02:57 2014] [error] (32)Broken pipe: write_data failed
>>>      [Wed Sep 03 16:02:57 2014] [error] command failed: failed to get client
>>>      block (data)
>>>      in apache error_log, but it seems like there are no relations in time
>>>      between these errors and busy moment.
>>>
>>>      So, the questions:
>>>      1) are there any way to know what is happening in this situation? What
>>>      threads are running, etc... I'm not sure the reason is in mono itself, may
>>>      be the reason is in my application. Full profiling on production server is
>>>      not possible, I mean just a few statistics,
>>>      2) if the reason is in garbage collector: are there any ways to tune it?
>>>      Or to switch from sgen to old Boehm or so on?
>>>
>>>      Any help are highly appreciated!
>>>
>>>      P.S. Mono 3.2.8 compiled from sources on standard CentOS 6.5
>>>      # mono -V
>>>      Mono JIT compiler version 3.2.8 (tarball Wed Jun 11 00:48:42 MSK 2014)
>>>      Copyright (C) 2002-2014 Novell, Inc, Xamarin Inc and Contributors.
>>>      www.mono-project.com <http://www.mono-project.com>
>>>          TLS:           __thread
>>>          SIGSEGV:       altstack
>>>          Notifications: epoll
>>>          Architecture:  amd64
>>>          Disabled:      none
>>>          Misc:          softdebug
>>>          LLVM:          supported, not enabled.
>>>          GC:            sgen
>>>
>>>      # httpd -v
>>>      Server version: Apache/2.2.15 (Unix)
>>>      Server built:   Apr  3 2014 23:56:16
>>>
>>>      # uname -a
>>>      Linux web1.server 2.6.32-431.17.1.el6.x86_64 #1 SMP Wed May 7 23:32:49 UTC
>>>      2014 x86_64 x86_64 x86_64 GNU/Linux
>>>
>>>
>>>      With best wishes,
>>>      Max Karavaev
>>>      _______________________________________________
>>>      Mono-list maillist  - Mono-list at lists.ximian.com
>>>      <mailto:Mono-list at lists.ximian.com>
>>>      http://lists.ximian.com/mailman/listinfo/mono-list