Details
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Bug
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Resolution: Fixed
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Medium
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3.8.7, 4.0.7, 4.1.4, 4.2.0
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None
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Operating System: Linux 2.6.20.4-grsec
PHP Version: 4.4.6-0.dotdeb.2
Database and version: MySQL 5.0.32-Dotdeb_1.dotdeb.1-log
Browser (and version): ALL
Description
When facing a huge number of objects in the trash ( > 10 k), it might not be possible to delete anything at all from the trash when using MySQL InnoDB or any other transactionnal database.
Cause of the problem : the $db->begin() and $db->commit() surround the whole loop on the total objects to purge.
Either the script will hit the PHP_TIME_LIMIT ( on a 10k+ objects purge and a 20k+ records in a content object tree ) without $db->commit() being issued : the whole first part of the purge is rollbacked internally in MySQL
Or the script will be the chosen victim of a InnoDB deadlock situation (hence an eZ Fatal Error without the commit being issued to the database)
Proposed enhancement : as the "empty trash" is a definitive destructive operation chosen by the user, one can reduce the atomicity of the operation by "batching" the content objects purge :
kernel/content/trash.php around line 92
----------------------------
Index: D:/workspace/ezpublish_trunk/ezpublish_trunk_3.8/kernel/content/trash.php
===================================================================
--- D:/workspace/ezpublish_trunk/ezpublish_trunk_3.8/kernel/content/trash.php (revision 18795)
+++ D:/workspace/ezpublish_trunk/ezpublish_trunk_3.8/kernel/content/trash.php (working copy)
@@ -95,6 +95,13 @@
null,
true );
+ // FIX : purge (at least a part) of a huge number (1k+) of objects
+ $useFakeBatchMode = false; $fakeBatchModeLimit = 25; $fakeBatchModeCounter = 0;
+ if (count($objectList) > 25)
+ {
+ $useFakeBatchMode = true;
+ }
+ // EOF FIX : purge (at least a part) of a huge number (1k+) of objects
$db =& eZDB::instance();
$db->begin();
foreach ( array_keys( $objectList ) as $key )
@@ -101,6 +108,17 @@
{
$object =& $objectList[$key];
$object->purge();
+ // FIX : purge (at least a part) of a huge number (1k+) of objects
+ if ($useFakeBatchMode == true)
+ {
+ $fakeBatchModeCounter++;
+ if ($fakeBatchModeCounter > $fakeBatchModeLimit)
+ {
+ $db->commit();
+ $db->begin();
+ }
+ }
+ // EOF FIX : purge (at least a part) of a huge number (1k+) of objects
}
$db->commit();
}
----------------------------
( Not proposed as file attachement because it is a "rough" patch : one could wish to change the object count threshold - here 25 - according to its web server/database server architecture )
This enhancement also diminish the period of time during which InnoDB will maintain the locks on the impacted rows/tables (hence, limiting the number of deadlocks related eZ Fatal Errors on other pages calls).
If the script dies anyway, at least some of the trash has been emptied ( I was able to empty a 15k+ objects trash in four steps ).
