[Pacemaker] [corosync] Corosync 2.1.0 dies on both nodes in cluster

Andrew Martin amartin at xes-inc.com
Tue Nov 6 23:47:25 UTC 2012


A bit more data on this problem: I was doing some maintenance and had to briefly disconnect storagequorum's connection to the STONITH network (ethernet cable #7 in this diagram): 
http://sources.xes-inc.com/downloads/storagecluster.png 


Since corosync has two rings (and is in active mode), this should cause no disruption to the cluster. However, as soon as I disconnected cable #7, corosync on storage0 died (corosync was already stopped on storage1), which caused pacemaker on storage0 to also shutdown. I was not able to obtain a coredump this time as apport is still running on storage0. 


What else can I do to debug this problem? Or, should I just try to downgrade to corosync 1.4.2 (the version available in the Ubuntu repositories)? 


Thanks, 


Andrew 

----- Original Message -----

From: "Andrew Martin" <amartin at xes-inc.com> 
To: "Angus Salkeld" <asalkeld at redhat.com> 
Cc: discuss at corosync.org, pacemaker at oss.clusterlabs.org 
Sent: Tuesday, November 6, 2012 2:01:17 PM 
Subject: Re: [corosync] [Pacemaker] Corosync 2.1.0 dies on both nodes in cluster 


Hi Angus, 


I recompiled corosync with the changes you suggested in exec/main.c to generate fdata when SIGBUS is triggered. Here 's the corresponding coredump and fdata files: 
http://sources.xes-inc.com/downloads/core.13027 
http://sources.xes-inc.com/downloads/fdata.20121106 



(gdb) thread apply all bt 


Thread 1 (Thread 0x7ffff7fec700 (LWP 13027)): 
#0 0x00007ffff775bda3 in qb_rb_chunk_alloc () from /usr/lib/libqb.so.0 
#1 0x00007ffff77656b9 in ?? () from /usr/lib/libqb.so.0 
#2 0x00007ffff77637ba in qb_log_real_va_ () from /usr/lib/libqb.so.0 
#3 0x0000555555571700 in ?? () 
#4 0x00007ffff7bc7df6 in ?? () from /usr/lib/libtotem_pg.so.5 
#5 0x00007ffff7bc1a6d in rrp_deliver_fn () from /usr/lib/libtotem_pg.so.5 
#6 0x00007ffff7bbc8e2 in ?? () from /usr/lib/libtotem_pg.so.5 
#7 0x00007ffff775d46f in ?? () from /usr/lib/libqb.so.0 
#8 0x00007ffff775cfe7 in qb_loop_run () from /usr/lib/libqb.so.0 
#9 0x0000555555560945 in main () 




I've also been doing some hardware tests to rule it out as the cause of this problem: mcelog has found no problems and memtest finds the memory to be healthy as well. 


Thanks, 


Andrew 
----- Original Message -----

From: "Angus Salkeld" <asalkeld at redhat.com> 
To: pacemaker at oss.clusterlabs.org, discuss at corosync.org 
Sent: Friday, November 2, 2012 8:18:51 PM 
Subject: Re: [corosync] [Pacemaker] Corosync 2.1.0 dies on both nodes in cluster 

On 02/11/12 13:07 -0500, Andrew Martin wrote: 
>Hi Angus, 
> 
> 
>Corosync died again while using libqb 0.14.3. Here is the coredump from today: 
>http://sources.xes-inc.com/downloads/corosync.nov2.coredump 
> 
> 
> 
># corosync -f 
>notice [MAIN ] Corosync Cluster Engine ('2.1.0'): started and ready to provide service. 
>info [MAIN ] Corosync built-in features: pie relro bindnow 
>Bus error (core dumped) 
> 
> 
>Here's the log: http://pastebin.com/bUfiB3T3 
> 
> 
>Did your analysis of the core dump reveal anything? 
> 

I can't get any symbols out of these coredumps. Can you try get a backtrace? 

> 
>Is there a way for me to make it generate fdata with a bus error, or how else can I gather additional information to help debug this? 
> 

if you look in exec/main.c and look for SIGSEGV you will see how the mechanism 
for fdata works. Just and a handler for SIGBUS and hook it up. Then you should 
be able to get the fdata for both. 

I'd rather be able to get a backtrace if possible. 

-Angus 

> 
>Thanks, 
> 
> 
>Andrew 
> 
>----- Original Message ----- 
> 
>From: "Angus Salkeld" <asalkeld at redhat.com> 
>To: pacemaker at oss.clusterlabs.org, discuss at corosync.org 
>Sent: Thursday, November 1, 2012 5:47:16 PM 
>Subject: Re: [corosync] [Pacemaker] Corosync 2.1.0 dies on both nodes in cluster 
> 
>On 01/11/12 17:27 -0500, Andrew Martin wrote: 
>>Hi Angus, 
>> 
>> 
>>I'll try upgrading to the latest libqb tomorrow and see if I can reproduce this behavior with it. I was able to get a coredump by running corosync manually in the foreground (corosync -f): 
>>http://sources.xes-inc.com/downloads/corosync.coredump 
> 
>Thanks, looking... 
> 
>> 
>> 
>>There still isn't anything added to /var/lib/corosync however. What do I need to do to enable the fdata file to be created? 
> 
>Well if it crashes with SIGSEGV it will generate it automatically. 
>(I see you are getting a bus error) - :(. 
> 
>-A 
> 
>> 
>> 
>>Thanks, 
>> 
>>Andrew 
>> 
>>----- Original Message ----- 
>> 
>>From: "Angus Salkeld" <asalkeld at redhat.com> 
>>To: pacemaker at oss.clusterlabs.org, discuss at corosync.org 
>>Sent: Thursday, November 1, 2012 5:11:23 PM 
>>Subject: Re: [corosync] [Pacemaker] Corosync 2.1.0 dies on both nodes in cluster 
>> 
>>On 01/11/12 14:32 -0500, Andrew Martin wrote: 
>>>Hi Honza, 
>>> 
>>> 
>>>Thanks for the help. I enabled core dumps in /etc/security/limits.conf but didn't have a chance to reboot and apply the changes so I don't have a core dump this time. Do core dumps need to be enabled for the fdata-DATETIME-PID file to be generated? right now all that is in /var/lib/corosync are the ringid_XXX files. Do I need to set something explicitly in the corosync config to enable this logging? 
>>> 
>>> 
>>>I did find find something else interesting with libqb this time. I compiled libqb 0.14.2 for use with the cluster. This time when corosync died I noticed the following in dmesg: 
>>>Nov 1 13:21:01 storage1 kernel: [31036.617236] corosync[13305] trap divide error ip:7f657a52e517 sp:7fffd5068858 error:0 in libqb.so.0.14.2[7f657a525000+1f000] 
>>>This error was only present for one of the many other times corosync has died. 
>>> 
>>> 
>>>I see that there is a newer version of libqb (0.14.3) out, but didn't see a fix for this particular bug. Could this libqb problem be related to the corosync to hang up? Here's the corresponding corosync log file (next time I should have a core dump as well): 
>>>http://pastebin.com/5FLKg7We 
>> 
>>Hi Andrew 
>> 
>>I can't see much wrong with the log either. If you could run with the latest 
>>(libqb-0.14.3) and post a backtrace if it still happens, that would be great. 
>> 
>>Thanks 
>>Angus 
>> 
>>> 
>>> 
>>>Thanks, 
>>> 
>>> 
>>>Andrew 
>>> 
>>>----- Original Message ----- 
>>> 
>>>From: "Jan Friesse" <jfriesse at redhat.com> 
>>>To: "Andrew Martin" <amartin at xes-inc.com> 
>>>Cc: discuss at corosync.org, "The Pacemaker cluster resource manager" <pacemaker at oss.clusterlabs.org> 
>>>Sent: Thursday, November 1, 2012 7:55:52 AM 
>>>Subject: Re: [corosync] Corosync 2.1.0 dies on both nodes in cluster 
>>> 
>>>Ansdrew, 
>>>I was not able to find anything interesting (from corosync point of 
>>>view) in configuration/logs (corosync related). 
>>> 
>>>What would be helpful: 
>>>- if corosync died, there should be 
>>>/var/lib/corosync/fdata-DATETTIME-PID of dead corosync. Can you please 
>>>xz them and store somewhere (they are quiet large but well compressible). 
>>>- If you are able to reproduce problem (what seems like you are), can 
>>>you please allow generating of coredumps and store somewhere backtrace 
>>>of coredump? (coredumps are stored in /var/lib/corosync as core.PID, and 
>>>way to obtain coredump is gdb corosync /var/lib/corosync/core.pid, and 
>>>here thread apply all bt). If you are running distribution with ABRT 
>>>support, you can also use ABRT to generate report. 
>>> 
>>>Regards, 
>>>Honza 
>>> 
>>>Andrew Martin napsal(a): 
>>>> Corosync died an additional 3 times during the night on storage1. I wrote a daemon to attempt and start it as soon as it fails, so only one of those times resulted in a STONITH of storage1. 
>>>> 
>>>> I enabled debug in the corosync config, so I was able to capture a period when corosync died with debug output: 
>>>> http://pastebin.com/eAmJSmsQ 
>>>> In this example, Pacemaker finishes shutting down by Nov 01 05:53:02. For reference, here is my Pacemaker configuration: 
>>>> http://pastebin.com/DFL3hNvz 
>>>> 
>>>> It seems that an extra node, 16777343 "localhost" has been added to the cluster after storage1 was STONTIHed (must be the localhost interface on storage1). Is there anyway to prevent this? 
>>>> 
>>>> Does this help to determine why corosync is dying, and what I can do to fix it? 
>>>> 
>>>> Thanks, 
>>>> 
>>>> Andrew 
>>>> 
>>>> ----- Original Message ----- 
>>>> 
>>>> From: "Andrew Martin" <amartin at xes-inc.com> 
>>>> To: discuss at corosync.org 
>>>> Sent: Thursday, November 1, 2012 12:11:35 AM 
>>>> Subject: [corosync] Corosync 2.1.0 dies on both nodes in cluster 
>>>> 
>>>> 
>>>> Hello, 
>>>> 
>>>> I recently configured a 3-node fileserver cluster by building Corosync 2.1.0 and Pacemaker 1.1.8 from source. All of the nodes are running Ubuntu 12.04 amd64. Two of the nodes (storage0 and storage1) are "real" nodes where the resources run (a DRBD disk, filesystem mount, and samba/nfs daemons), while the third node (storagequorum) is in standby mode and acts as a quorum node for the cluster. Today I discovered that corosync died on both storage0 and storage1 at the same time. Since corosync died, pacemaker shut down as well on both nodes. Because the cluster no longer had quorum (and the no-quorum-policy="freeze"), storagequorum was unable to STONITH either node and just left the resources frozen where they were running, on storage0. I cannot find any log information to determine why corosync crashed, and this is a disturbing problem as the cluster and its messaging layer must be stable. Below is my corosync configuration file as well as the corosync log file from each! 
! 
>n! 
>>o! 
>>>de during 
>>>this period. 
>>>> 
>>>> corosync.conf: 
>>>> http://pastebin.com/vWQDVmg8 
>>>> Note that I have two redundant rings. On one of them, I specify the IP address (in this example 10.10.10.7) so that it binds to the correct interface (since potentially in the future those machines may have two interfaces on the same subnet). 
>>>> 
>>>> corosync.log from storage0: 
>>>> http://pastebin.com/HK8KYDDQ 
>>>> 
>>>> corosync.log from storage1: 
>>>> http://pastebin.com/sDWkcPUz 
>>>> 
>>>> corosync.log from storagequorum (the DC during this period): 
>>>> http://pastebin.com/uENQ5fnf 
>>>> 
>>>> Issuing service corosync start && service pacemaker start on storage0 and storage1 resolved the problem and allowed the nodes to successfully reconnect to the cluster. What other information can I provide to help diagnose this problem and prevent it from recurring? 
>>>> 
>>>> Thanks, 
>>>> 
>>>> Andrew Martin 
>>>> 
>>>> _______________________________________________ 
>>>> discuss mailing list 
>>>> discuss at corosync.org 
>>>> http://lists.corosync.org/mailman/listinfo/discuss 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> 
>>>> _______________________________________________ 
>>>> discuss mailing list 
>>>> discuss at corosync.org 
>>>> http://lists.corosync.org/mailman/listinfo/discuss 
>>> 
>>> 
>> 
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>>> 
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>> 
>> 
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>> 
> 
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> 

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