This page last changed on Nov 21, 2008 by jlargman.

This page covers conditions under which Confluence will become unresponsive and need a restart. It does not cover stack trace error messages thrown from specific uses of Confluence, nor does it cover inability to get Confluence running. Below are the most common reasons Confluence will crash.

Known causes for crashes

Out of Memory: Permgen space
Search the atlassian-confluence.log file for the text java.lang.OutOfMemoryError: PermGen space. You can solve this problem by increasing your PermGen space to 256M. Make sure to specify PermGen space as opposed to heap space.

Out of Memory: Heap space
Managing memory settings requires some analysis; there is no appropriate universal recommendation. Read through our suggestions for setting the ideal settings for your environment.

Plugin related issues
The following plugins are known to cause suspended threads:

In some cases, these plugins may need upgrading or other maintenance. In some cases they must be disabled. On each plugin's page, you can browse the jira issues.

Databases: SQL Server 2000 and HSQLDB
SQL Server 2000 has been problematic. Use MSSQL 2005 instead. See our Known Issues for SQL Server.
The in-memory database HSQLDB is for evaluation purposes only. Make sure to migrate to a new database when moving into production.

XML Backups
The XML backup is known to be inefficient. With large instances, it can crash the server. Move to the Alternative Backup Strategy for an efficient and reliable backup solution.

Upgrade Confluence
There are a variety of upgrades that have been improved through our versions. Make sure to stay current with Confluence versions. The following bugs are known to have caused crashes or hangs:

Upgrade Java Version
Some issues are corrected and others are improved by Java 1.6. Java 1.6 is supported in Confluence 2.7.

Tools for assessing problems.

It's easy and effective to take thread dumps. If CPU is spiking to 100%, try Live Monitoring Using the JMX Interface, in particular with the Top threads plugin.

How to get support

Open a Support Request. At the minimum, capture a thread dump at the time of the crash, and submit your logs and System Information.

Document generated by Confluence on Dec 03, 2008 15:14