#22674 [Com]: Unexpected build-up of persistent connections
ID: 22674
Comment by: fred dot cohen at iridium dot com
Reported By: msquillace at sogei dot it
Status: Open
Bug Type: OCI8 related
Operating System: Redhat 7.3
PHP Version: 4.3.1
New Comment:
this setting in httpd.conf helps the problem considerably:
MaxRequestsPerChild 100
I've seen situations where every apache process would have two oracle
connections open. Trick seems to be to limit the life of the apache
process.
Previous Comments:
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[2003-03-13 08:31:14] msquillace at sogei dot it
Environment is Linux RedHat 7.3, Apache 1.3.27, PHP 4.3.1 DSO with OCI8
(8.1.7.0) and several other extensions; the Oracle database (8.1.7.3)
is on a Win2k server.
The described behaviour also shows in PHP 4.2.2 and PHP 4.2.3, and with
Oracle 9i, and can be reproduced (I usually begin by starting Apache
with the -X switch) e.g. with the following script:
<?php
OCIInternalDebug(1);
$conn0 = OCIPLogon("user1","pwd1", "db1");
$conn1 = OCILogon("user2","pwd2", "db1");
//sleep(10);
print "<pre>".OCIServerVersion($conn0)."<br>";
print OCIServerVersion($conn1)."</pre>";
?>
The number of outstanding Oracle sessions can be checked from sqlplus:
select machine,process,username,status from v$session order by
process;
where "process" shows the PID of the Apache process executing the PHP
script.
I'd expect to see exactly one persistent session (for user1) associated
with the single Apache process after running the script, but I observe
two instead, one for each user.
Running the same script again doesn't change the situation.
There's more, though: if at this point I run a similar script where
I've changed the OCILogon to OCINLogon, I observe the correct behaviour
of (an additional) new session being first created for user2 then
destroyed at script end, but when I subsequently re-run the original
script (OCILogon), another persistent session for user2 appears!
This leads to a persistent session build-up with Oracle eventually
complaining for too many sessions.
As a side (but important) note, I observed that while Oracle is
case-insensitive with regard to the user credentials and the db alias
used in a connection, the OCI8 extension is case-sensitive: if I make
two OCIPLogon(s) whose arguments differ only in case I get two
persistent Oracle sessions.
I'd suggest converting the (left- and right-trimmed) arguments to upper
or lower case in the extension before checking for reusability against
already existing sessions.
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