develooper Front page | perl.dbi.users | Postings from December 2017

Hunting down (possible) memory leak in DBD::Oracle

Thread Next
From:
Fennell, Brian
Date:
December 16, 2017 22:19
Subject:
Hunting down (possible) memory leak in DBD::Oracle
Message ID:
CY4PR14MB17199CB679A575752ACBFB8AA2080@CY4PR14MB1719.namprd14.prod.outlook.com
Dear DBI people - 

I am trying to port some old perl code to a new box.  (see Details below) Needless to say the original box and code works fine, but the new box (and old code) does not.
Specifically what I am seeing is that when I select slightly over a million records from a specific join of two tables (to be dumped one row at a time into a TSV file) we get strange ORA-NNNNN errors that don't really make any sense in this context.
The Same database and same table works fine on the original box with the large number of records.  2 million records always causes errors but two groups of 1million (divided up by ROWNUM - the EXACT same rows) causes no errors.  I am using a test database with little activity do I am reasonably certain that the queries deal with the same rows.
So I am thinking the problem is data volume and not any specific piece of data (originally I thought it might be an odd string/data related error, but I am starting to think it is a memory leak of some kind).
The error always happens inside of fetchrow_array - and "$dbh->trace( 4 , $filename )" shows that the error originates inside the DBD::Oracle module while reading field 3 of 6.  
Researching the ORA-NNNNNN error gives a perfectly sane description that makes no sense at all in the context of reading a specific field.  

We are going thru an Audit and tightening up security so there are some things (like REAL hostnames and REAL column/table names) that I cannot share - but I will try to share as much as I can.

The Host I am calling "prod" below is the only one NOT exhibiting this issue.

Things I want to try - 

1) recompile the DBD::Oracle module on Host "sandbox" with "perl Makefile.PL -g" and then use Valgrind.  I haven't used Valgrind before, but I guess it is time to learn.
2) Anything else this list suggests. 

Details:

Host: prod
OS: Red Hat Enterprise Linux AS release 4 (Nahant Update 4)
Perl: 5.8.8 built for x86_64-linux
DBI: 1.53
DBD::Oracle: 1.19
Oracle: 10.2.0.1.0

Host: dev
OS: Red Hat Enterprise Linux Server release 6.5 (Santiago)
Perl: 5.16.1  built for x86_64-linux
DBI: 1.631
DBD::Oracle: 1.74
Oracle: 11.2.0.3.0

Host: prodnew
OS: Red Hat Enterprise Linux Server release 6.5 (Santiago)
Perl: 5.16.1  built for x86_64-linux
DBI: 1.631
DBD::Oracle: 1.70
Oracle: 11.2.0.1.0

Host: sandbox
OS: CentOS Linux release 7.4.1708 (Core)
Perl: 5.16.3  built for x86_64-linux-thread-multi
DBI: 1.637
DBD::Oracle: 1.74
Oracle: 12.1.0.2.0

--
Brian Fennell, Software Engineer | Radial
O: 610 491 7308 | M: 484 354 1699
fennellb@radial.com

The information contained in this electronic mail transmission is intended only for the use of the individual or entity named in this transmission. If you are not the intended recipient of this transmission, you are hereby notified that any disclosure, copying or distribution of the contents of this transmission is strictly prohibited and that you should delete the contents of this transmission from your system immediately. Any comments or statements contained in this transmission do not necessarily reflect the views or position of Radial or its subsidiaries and/or affiliates.

 >++++++++++[>++++++++++>++++++++++>++++++++++>+++++++++++>+++++++++++>++++++++++>+++++++++++>+++++++++++><<<<<<<<<-]>-->++>+>>>+>-->--><<<<<<<<<>.>.>.>.>.>.>.>.

Thread Next


nntp.perl.org: Perl Programming lists via nntp and http.
Comments to Ask Bjørn Hansen at ask@perl.org | Group listing | About