ID: 47712 Comment by: ninzya at inbox dot lv Reported By: ninzya at inbox dot lv Status: Open Bug Type: Scripting Engine problem Operating System: Windows XP PHP Version: 5.3.0beta1 New Comment:
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. Previous Comments: ------------------------------------------------------------------------ [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. ------------------------------------------------------------------------ [2009-03-20 12:34:59] ninzya at inbox dot lv And here is the screenshot of the output of MySql query browser after executing SQL query i mentioned above: http://www.stepanov.lv/pub/mysql.jpg ------------------------------------------------------------------------ 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 -- Edit this bug report at http://bugs.php.net/?id=47712&edit=1
