[dsc] CPU problem

Elias Abacioglu elias.rabi at gmail.com
Wed Apr 23 13:22:46 UTC 2014


Hi,

Would like to bump this to see if anyone else has input on what I should do?
Cause my alternative is to stop using DSC.

2014-03-06 16:15 GMT+01:00 Elias Abacioglu <elias.rabi at gmail.com>:
> Ok, done.
> A 4.6 MB core file was created.
>
> But I really don't know how to use gdb (I tried the bt command).
>
> I executed gdb like this:
> # gdb /usr/bin/dsc ./core
> GNU gdb (Ubuntu/Linaro 7.4-2012.04-0ubuntu2.1) 7.4-2012.04
> Copyright (C) 2012 Free Software Foundation, Inc.
> License GPLv3+: GNU GPL version 3 or later
> <http://gnu.org/licenses/gpl.html>
> This is free software: you are free to change and redistribute it.
> There is NO WARRANTY, to the extent permitted by law.  Type "show copying"
> and "show warranty" for details.
> This GDB was configured as "x86_64-linux-gnu".
> For bug reporting instructions, please see:
> <http://bugs.launchpad.net/gdb-linaro/>...
> Reading symbols from /usr/bin/dsc...(no debugging symbols found)...done.
> [New LWP 27928]
>
> warning: Can't read pathname for load map: Input/output error.
> Core was generated by `/usr/bin/dsc -p
> /var/run/dsc-statistics-collector/dsc-collector_default.cfg'.
> Program terminated with signal 6, Aborted.
> #0  0x00007ff2da182a08 in poll () from /lib/x86_64-linux-gnu/libc.so.6
> (gdb) bt
> #0  0x00007ff2da182a08 in poll () from /lib/x86_64-linux-gnu/libc.so.6
> #1  0x00007ff2da9785f8 in ?? () from
> /usr/lib/x86_64-linux-gnu/libpcap.so.0.8
> #2  0x0000000000406544 in ?? ()
> #3  0x0000000000403fba in ?? ()
> #4  0x00007ff2da0bb76d in __libc_start_main () from
> /lib/x86_64-linux-gnu/libc.so.6
> #5  0x0000000000404469 in ?? ()
>
> How shall I proceed?
>
> /Elias
>
>
>
> 2014-03-06 2:35 GMT+01:00 Duane Wessels <wessels at measurement-factory.com>:
>
>> You probably need to increase the corefile size limit.  Try 'ulimit -c
>> unlimited' before you run dsc.
>>
>> DW
>>
>>
>>
>> On Wed, 5 Mar 2014, Elias Abacioglu wrote:
>>
>>> no core file :( I guess the ubuntu package isn't built with debugging
>>> symbols
>>>
>>>
>>> 2014-03-05 9:55 GMT+01:00 Elias Abacioglu <elias.rabi at gmail.com>:
>>>       Hi Duane,
>>>       I've attached the output from the debug run. I doubt it will show
>>> anything since it doesn't spike the CPU instantly. It
>>>       does it after it's been running for some time.
>>> I just restarted DSC(and running in foreground so I get the output). When
>>> it goes to 100% CPU I will do a kill -ABRT.
>>> ulimit -c was 0 so I guess unlimited size of core file.
>>>
>>>
>>> Thanks!
>>> Elias
>>>
>>>
>>> 2014-03-04 14:53 GMT+01:00 Duane Wessels
>>> <wessels at measurement-factory.com>:
>>>
>>>       Hello Elias,
>>>
>>>       I have two suggestions:
>>>
>>>       1) you can run dsc in a debugging mode.  For example:
>>>
>>>          $ sudo dsc -d -f /usr/local/etc/dsc/dsc.conf
>>>
>>>          that might help identify the problem.
>>>
>>>       2) second option is to send the running process an ABRT signal
>>>          while it is running:
>>>          $ sudo kill -ABRT dsc-pid
>>>
>>>         That signal should cause the dsc process to make a core dump,
>>> although
>>>         sometimes you have take some extra steps to make sure the core
>>> file
>>>         gets created.  Check "ulimit -c" and make sure dsc's working
>>> directory
>>>         is writable.
>>>
>>>         When you have a core dump, and if the binary is compiled with
>>> debugging
>>>         symbols, then you can use gdb to pinpoint where its getting
>>> stuck.
>>>
>>>       DW
>>>
>>>
>>>       On Tue, 25 Feb 2014, Elias Abacioglu wrote:
>>>
>>>       Hi all,
>>>
>>>       I've joined this mailing list cause I have what I would assume to
>>> be an
>>>       unusual problem.
>>>       I have 5 name servers running bind 9 and with similar setup.
>>>
>>>       DSC works on all of them but causes problem on the fifth.
>>>       It uses 100% CPU on one core.
>>>       I tried updating the entire system (apt-get update && apt-get
>>> upgrade). It
>>>       did not help.
>>>       DSC is installed using a configuration manager so installation is
>>> identical.
>>>
>>>       On all servers it spawns two processes, these two
>>>       /usr/bin/dsc -p
>>> /var/run/dsc-statistics-collector/dsc-collector_default.cfg
>>>       \_ [dsc] <defunct>
>>>
>>>       But on that faulty server after a short while it starts eating the
>>> CPU. And
>>>       it doesn't seem to be so more DNS usage on that nameserver.
>>>       The version is 201106061022-4, which is the one found in Ubuntu
>>> 12.04
>>>       (precise) repos.
>>>       $ cat /etc/issue
>>>       Ubuntu 12.04.3 LTS \n \l
>>>
>>>       How should I continue with this? Can't have one of two cores
>>> running at
>>>       100% all the time.
>>>
>>>       Regards,
>>>       Elias
>>> _______________________________________________
>>> dsc mailing list
>>> dsc at measurement-factory.com
>>> http://www.measurement-factory.com/mailman/listinfo/dsc
>>>
>>>
>>>
>>>
>>>
>



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