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Re: slapd stability problems with add/change operations

--On Thursday, August 18, 2005 2:13 PM +0200 Adrian Gschwend <adrian.gschwend@bfh.ch> wrote:

Quanah Gibson-Mount wrote:

Once you are in gdb, then the easiest thing to do is to get a backtrace
of where you are at:

thr apply all bt

will do a back trace of where all the existing threads are currently at.

thanks for the hint, I compiled the deamon with exactly the same options on FreeBSD, actually the only thing I added to the Makefile of the ports-collection is:

CFLAGS+=                -g

then I copied the binary I got to the original location, it's 5.4MB
instead of about 800k before. I can attach to the process and I do get
backtraces when I do that once it started.

So we started to stress the server (without gdb attached to it for sure),
sync in loop and add/del operations on the server. And guess what, it
doesn't hang! We did around 600 add operations within 5 seconds,
something that locked the server very easily before. So we were a *bit*
confused and checked the log, what we found is this:

slapd[1144]: connection_input: conn=289 deferring operation: awaiting

we *never* saw this message in the release without debug information!?
How is that possible? As I said the only thing I changed is the debug
options, I didn't touch anything else.

So conclusion so far: With debug symbols we can't lock it, at least not
so far. Does that make sense? It does confuse me at least :)

No, it makes little sense to me. I always build with "-O2 -g" so I have an optimized build with debugging, and it functions no differently than as just "-O2".

Maybe you fixed something in your rebuild. ;)


Quanah Gibson-Mount
Principal Software Developer
ITSS/Shared Services
Stanford University
GnuPG Public Key: http://www.stanford.edu/~quanah/pgp.html

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