Re: slapd grows during SASL Binds

[Howard Chu <hyc@symas.com>]

Paul Turgyan wrote:
> We've seen the slapd's on our mail slaves trying to grow greater
> than the 2 gigabyte resident set size.  I spent two days
> w/ valgrind looking for memory leaks,  but I failed to find anything.
> I finally discovered that repeatedly binding and unbinding using a SASL/
> GSSAPI bind would cause slapd's resident set size and vm size to grow.  
> So I wrote
> a test program to SASL Bind,  issue a search,  and unbind.  The test 
> program  would
> do this sequence 10000 times before it stopped.  The test program  
> always issues
> the same exact search trying to eliminate any interferance from a 
> growing entry cache
> and/or  idlcache.

If valgrind doesn't show anything then you're going to have to get more 
invasive. One possibility is to test again with a stripped down 
configuration. Just measure the memory use from a single Bind and 
Unbind, with no search operation in between. Or just query the rootDSE. 
You can test this with a practically empty slapd.conf file (since the 
config database always exists).

Change the slapd shutdown handler to just call exit() immediately. That 
will prevent anything from cleaning up. It will give valgrind plenty of 
leaks to complain about. Compare a session using a single anonymous bind 
vs a session using a single SASL/GSSAPI bind. That will show you where 
the discrepancy in memory use came from.

--
  -- 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/