Re: (ITS#4254) back-hdb deadlock under load

[hyc@symas.com]

Thanks for the report. I'd been looking into this for a while now, been 
testing a fix here. Should be ready soon.

gael.roualland@oleane.net wrote:
> Full_Name: Gaël Roualland
> Version: 2.3.13
> OS: Linux
> URL: ftp://ftp.openldap.org/incoming/gael-roualland-051208.log
> Submission from: (NULL) (213.56.0.199)
>
>
> Hello,
>
> While benchmarking back-hdb on a large test directory running OpenLDAP 2.3.13,
> after a while all threads stop responding and the slapd process comes to a
> deadlock.
>  
> For the purpose of this bug report, I ran the test with slapd configured to run
> with only 4 threads, and I have attached to the locked threads with gdb.
> Relevant parts of the gdb session are in the uploaded file.
>
> As you can see, the 4 worker threads are competing for the lru mutex and cache
> rwlock. It looks like :
> - thread 6 wants to lock the lru mutex at cache.c:442, while it has the rwlock
> locked from cache.c:419
> - thread 7 wants to lock the rwlock at cache.c:602, while it has the lru mutex
> locked from cache.c:823
>
> Thanks,
>
> Gaël.
>
>
>   


-- 
  -- Howard Chu
  Chief Architect, Symas Corp.  http://www.symas.com
  Director, Highland Sun        http://highlandsun.com/hyc
  OpenLDAP Core Team            http://www.openldap.org/project/