[JIRA] Commented: (SSPCPP-473) occasional shibd crashes when using MySQL ODBC storage service on RHEL6

[BRIAN P KROTH (JIRA)]

    [ https://issues.shibboleth.net/jira/browse/SSPCPP-473?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14563#comment-14563 ] 

BRIAN P KROTH commented on SSPCPP-473:
--------------------------------------

Unfortunately I've been distracted by other problems and haven't fully tracked this down yet.

Here's what I can say:
- it's almost certainly myodbc/mysql related since, if I replace that storage backend with a sqlite one (still through unixodbc) it doesn't memleak, though the performance is (not unexpectedly) atrocious

- if i disable connection pooling in the /etc/odbcinst.ini file, then I don't see a memory leak, but the delay in spinning up a mysql connection for every connection is also atrocious (yes, yes, worker vs. prefork, but it's (old) php ...)

- newer versions of the myodbc driver require mysql-5.5+ support, which is not currently available in debian squeeze (6), which is a part of my delay in testing this further

> occasional shibd crashes when using MySQL ODBC storage service on RHEL6
> -----------------------------------------------------------------------
>
>                 Key: SSPCPP-473
>                 URL: https://issues.shibboleth.net/jira/browse/SSPCPP-473
>             Project: Shibboleth SP - C++
>          Issue Type: Bug
>      Security Level: Standard(Standard bug, may impact functionality but does not represent a security vulnerability ) 
>    Affects Versions: 2.4.3
>         Environment: RHEL6, Apache 2.2, SP 2.4.3 from RPM, and MySQL for storage service. Using RH supplied unixODBC and mysql-connector-odbc packages with default odbcinst.ini.
>            Reporter: Sebastien Otto Korner
>            Assignee: Scott Cantor
>         Attachments: shibd-crash-mode-1.txt, shibd-crash-mode-2.txt, shibd-crash-mode-3.txt
>
>
> When using the ODBC storage service with MySQL on RHEL6 shibd crashes periodically.  Our web servers are 1/2 RHEL5 and 1/2 RHEL6, with load spread equally between them.  The shibd on RHEL5 never crashes.  Without using the ODBC storage service shibd never crashes on any server.
> The crash frequency in terms of session creation is about once every thousand.  It does not appear to be a regular occurrence based on number of sessions since the last crash though.  For approximately half the crashes another crash follows within 30 minutes.
> Investigating the core files indicates two different failure modes, with MySQL use implicated in both.  Attached are traces representing the two failure modes.
> Let me know if you require more information.
> Thanks.
> Sebastien

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