[dsc] CPU problem

[Elias Abacioglu]

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
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>>
>>
>>
>>
>>