[ACCUMULO-1379] PermGen leak

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 1.4.3, 1.5.0
• Fix Version/s: 1.6.0
• Component/s: client

Environment

Linux/JBoss

• Assignee: John Vines
• Reporter: Mike Giordano
• Created: 03/May/13 16:10
• Updated: 10/Jun/16 20:31
• Resolved: 02/Oct/13 18:57

Description

Under version 1.3.7 we are using the following code to initialize a cloudbase connection during initialization of our web app:

ZooKeeperInstance instance = new ZooKeeperInstance(instanceName, zooKeepers);
connector = instance.getConnector(userId, password.getBytes());

The problem is that under the hood, this call creates several threads that are not cleaned up when the app is undeployed in JBoss. This is occurring without performing any scans or interacting with cloudbase in any other way. After relatively few redeploys of the app, the PermGen Space is OOM.

I can't find any reference in the cloudbase API akin to a close() method for the Connector object. This is a classloader leak effecting any webapp that is accessing cloudbase directly. The result of this leak is not simply orphaned threads, but thousands of classes not gc'd because the classloader itself can't be gc'd. This is what is filling up PermGen.

Issue Links

• breaks: ACCUMULO-2027 ZooKeeperInstance.close() not freeing resources in multithreaded env
• is duplicated by: ACCUMULO-1697 Thread leaks in Tomcat on hot-redeploy
• is superceded by: ACCUMULO-2128 Provide resource cleanup via static utility rather than Instance.close
• relates to: ACCUMULO-1858 Backport fix for Accumulo-1379 PermGen Leak to 1.4 and 1.5