ID: 47712
Updated by: johan...@php.net
Reported By: ninzya at inbox dot lv
-Status: Open
+Status: Feedback
Bug Type: MySQL related
Operating System: Windows XP
PHP Version: 5.3.0beta1
New Comment:
Can you give me some more details about your system and the
configuration, please.
I spent some time with load testing different configurations now using
mysqlnd, pconnects, and PHP's thread-safe mode and wasn't able to
reproduce this issue.
Maybe even try to come up with the shortest script possible showing the
issue ...
Previous Comments:
------------------------------------------------------------------------
[2009-03-25 12:24:45] ninzya at inbox dot lv
I guess i can not switch between libmysql and mysqlnd in PHP 5.3. I
have no tools to compile PHP myself with the proper library. If you know
where i can find PHP 5.3RC1 with libmysql, i would test it out right
away.
------------------------------------------------------------------------
[2009-03-25 12:19:04] kak dot serpom dot po dot yaitsam at gmail dot
com
Try to test this under PHP 5.3 with libmysql driver (not mysqlnd).
------------------------------------------------------------------------
[2009-03-25 07:28:35] ninzya at inbox dot lv
In most cases this bug is being hit when working with mysql, and only
during high concurrency. When there is no concurrency, or concurrency is
not big enough, bug does not trigger. Also i forgot to mention that PHP
is installed as a module.
Downloaded QA's PHP 5.3.0RC1 and tested it with both php_mysql and
php_mysqli extensions, bug is still present.
The page that is being executed during stress test contains 14 SQL
queries, 11 of them are SELECT queries. In most cases the 5th to 7th
SELECT queries are failing to return proper data using
mysql_fetch_assoc(). When the bug triggers, the values of returned array
(usually first on first two keys in the array) are being replaced with
irrelevant to SELECT result data, contents of those values are either
NULL or data that was stored in DB, but used to appear in previous SQL
queries. In the example above you can clearly see that the value of key
'id' in array $row is 'SHARED', but shared is the value of another field
in another SQL query i used to execute. Probably, mysqlnd is somehow
sharing memory between requests, and somehow memory of another request
being processed concurrently is being passed to current request. Another
assumption may be that the mysqlnd somehow bypasses update of currently
used cached zval.
Anyway, if this is mysqlnd related, still don't know how to explain
warning with empty constant mentioned in previous report.
------------------------------------------------------------------------
[2009-03-24 18:49:53] kak dot serpom dot po dot yaitsam at gmail dot
com
I guess the trouble is in MySQL Native Driver (mysqlnd). No?
------------------------------------------------------------------------
[2009-03-21 22:45:24] ninzya at inbox dot lv
Tested under PHP 5.2.9-1, the problem does not exist with that version
of PHP.
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The remainder of the comments for this report are too long. To view
the rest of the comments, please view the bug report online at
http://bugs.php.net/47712
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Edit this bug report at http://bugs.php.net/?id=47712&edit=1
