[389-users] CMP operations against pwdPolicySubentry hanging

[Rich Megginson]

On 02/23/2012 01:13 PM, Iain Morgan wrote:
> On Wed, Feb 15, 2012 at 18:19:10 -0600, Rich Megginson wrote:
>> On 02/15/2012 03:51 PM, Iain Morgan wrote:
>>> On Wed, Feb 15, 2012 at 15:04:52 -0600, Rich Megginson wrote:
>>>> On 02/15/2012 01:56 PM, Iain Morgan wrote:
>>>>> On Tue, Feb 14, 2012 at 19:54:39 -0600, Rich Megginson wrote:
>>>>>> On 02/14/2012 06:37 PM, Iain Morgan wrote:
>>>>>>> Hello,
>>>>>>>
>>>>>>> On a fairly frequent basis, one of my 389 DS servers hangs after certain
>>>>>>> CMP operations. Once this happens, the server cannot be shutdown
>>>>>>> gracefully. This has been going on for several weeks, and I have not yet
>>>>>>> found a solution.
>>>>>>>
>>>>>>> My setup consists of two systems running RHEL 6.2 with 389 DS 1.2.9.16.
>>>>>>> Multimaster replication is enabled between the two servers, but the
>>>>>>> client systems (currently just two test systems) preferrentially use the
>>>>>>> same server, ServerA. The second server, ServerB, is the one which is
>>>>>>> experiencing the problem.
>>>>>>>
>>>>>>> We are using class-of-service entries to to set the values for the
>>>>>>> shadowMax, shadowMin, and shadowWarning attributes. And we are
>>>>>>> conditionally setting a pwdPolicySubentry attribute for some entries in
>>>>>>> the same manner.
>>>>>>>
>>>>>>> If I execute an ldapcompare command, such as the following:
>>>>>>>
>>>>>>> # ldapcompare uid=imorgan,ou=People,dc=example,dc=com \
>>>>>>> 	pwdpolicysubentry:"cn=Special Policy,ou=Policies,dc=example,dc=com"
>>>>>>>
>>>>>>> the command will occassionally hang. Most of the time, the command
>>>>>>> succeeds and indicates that the attribute is not defined for that entry.
>>>>>>> However, once or twice a day it will simply hang.
>>>>>>>
>>>>>>> The access log shows that the CMP request was received, but no result is
>>>>>>> logged. After this occurs, the server will not shut down gracefully. The
>>>>>>> init script fails to shut down the server and I end up having to send a
>>>>>>> SIGKILL to ns-slapd.
>>>>>> When you get the hang, can you attach to the process with gdb?
>>>>>> ps -ef|grep ns-slapd
>>>>>> gdb /usr/sbin/ns-slapd pid-of-ns-slapd
>>>>>>> The error log does not report any issues.
>>>>>>>
>>>>>>> CMP operations against other attributes, such as loginShell, do not seem
>>>>>>> to exhibit this problem. Also, the problem does not occur on ServerA;
>>>>>>> only on ServerB. Once the CMP operation has hung, comparisons against
>>>>>>> other attributes, even shadowMax, continue to work.
>>>>>>>
>>>>>>> As noted above, most of the time the CMP operation returns normally.
>>>>>>> However, if I reinitialize ServerB from ServerA, the problem occurs with
>>>>>>> the first CMP operation against ServerB.
>>>>>>>
>>>>>>> Both servers have the same set of RPMs and the dse.ldif on both systems
>>>>>>> do not have any significant differences.
>>>>>>>
>>>>>>> Has anyone seen a similar issue? Any suggestions on how to debug of fix
>>>>>>> this?
>>>>>>>
>>>>>>> A somewhat simplified and redacted version of the class-of-service
>>>>>>> configuration is listed below.
>>>>>>>
>>>>>>> Thanks
>>>>> A gzip'd copy of the 'thread apply all bt full' output is attached.
>>>>>
>>>> Thanks.  Can you do this again after installing the
>>>> 389-ds-base-debuginfo package?
>>>> debuginfo-install 389-ds-base
>>> Ah, sorry about that. Here's the updated output.
>>>
>>>> Are you using Views?
>>>> http://docs.redhat.com/docs/en-US/Red_Hat_Directory_Server/9.0/html/Administration_Guide/using-views.html
>>> No.
>>>
>> Thanks!  This looks like a symptom of
>> https://fedorahosted.org/389/ticket/247 fixed in 1.2.10
> Hello Rich,
>
> Thanks, I upgraded both of the servers to 1.2.10.1. Unfortunately, it
> did not resolve the issue. I also noticed that if I run the same
> ldapcompare command after the first try fails,
fails?  hangs?
> the server crashes. I
> can't say whether that is a change in the behaviour, but it is a new
> observation.
So with 1.2.10, in addition to the hang, you also get a crash?

Please file a ticket at https://fedorahosted.org/389 along with your 
configuration and steps to reproduce.
> I've attached gdb output for the case where the first ldapcompare is
> hanging. And, I've also attached the gdb analysis of the core dump.
>