On 2006-02-01, at 00.45, Tim Bunce wrote:
By which I presume you mean it appears to work fine because it doesn't
segfault. An underlying problem, such as memory corruption, may still
be present, just not causing any visible problem in you application.
(Sorry to be pessimistic.)
You're right, i may have been too optimistic. The issue has typically
required around 50 to 150 script runs to reproduce on RHEL 3. On RHEL
4 i've done more than 4000 runs without seeing segfaults, but as you
point out this still doesn't rule out the possibility of memory
corruption.
There are memory allocation debugging tools that may help to isolate
the original problem and so give some confidence that it's not present
in the other configurations.
I'am not really familiar with such tools, can you recommend a good
tool for this? How about Valgrind?
I've reported this issue to Oracle but does anyone have clues on what
is causing this or suggestions on how to get this fixed on the Perl
side? I'd really need to use -Dusemymalloc and Oracle Instant Client.
Why?
I don't have empirical data on this but several sources (among others
Perl distribution INSTALL file, mod_perl Cookbook) hint that -
Dusemymalloc may give better performance and use less memory.
Also, try http://www.data-plan.com/public/DBD-Oracle-1.17-RC6.tar.gz
I don't think there are any relevant changes but I'd be interested to
know if you get similar behaviour on the various systems.
I'll give it a try when i have the chance (possibly during next week).
aspa
