Home » Bugs » BUG 251 : ENHANCEMENT - Better connection pool leak detection ... via stack trace
 Bug 251 : ENHANCEMENT - Better connection pool leak detection ... via stack trace
Priority 
High
 Reported Version 
 
 Logged By 
Rob
Status 
Fixed
 Fixed Version 
2.5.0
 Assigned To 
 
Product 
Ebean - core
 Duplicate Of 
 
 Created 
17/03/2010
Updated 
17/03/2010
 Type 
Bug
  
Attachments 
No attachments

I have made a few tweaks to the connection pool leak detection.

...
datasource.h2.maxConnections=25
datasource.h2.capturestacktrace=true

Put the capturestacktrace = true parameter ... and then the Ebean DataSource will get the stack element array when we get a connection.

If the pool runs out of connections it will reset itself (or you can call the reset manually) ... and at that point busy connections will be checked to see if they are possible connection pools.

Also when the connection pool is shutdown the information on the busy connections are also dumped.

It is logged and also send to sys err. It is sent to sys err because the loggers stop working early in a JVM shutdown.
 
Rob 17 Mar 05:30
Logged information

The logged information is:

INFO: DataSourcePool [h2] grow pool; busy[24] size[24] max[25]
17/03/2010 05:17:48 com.avaje.ebeaninternal.server.lib.sql.DataSourcePool reset
INFO: Reseting DataSourcePool [h2]
17/03/2010 05:17:48 com.avaje.ebeaninternal.server.lib.sql.DataSourcePool reset
INFO: Busy Connections:
name[h2.1] startTime[1268803068504] stmt[null] createdBy[com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39)]
name[h2.2] startTime[1268803068506] stmt[null] createdBy[com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39)]

Rob 17 Mar 05:31
And the stack traces are output:

example:

17/03/2010 05:17:48 com.avaje.ebeaninternal.server.lib.sql.DataSourcePool closeBusyConnections
WARNING: DataSourcePool closing leaked connection? name[h2.1] lastUsed[Wed Mar 17 05:17:48 GMT 2010] createdBy[com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39)] lastStmt[null]
17/03/2010 05:17:48 com.avaje.ebeaninternal.server.lib.sql.DataSourcePool logStackElement
WARNING: Possible Leaked Connection: name[h2.1] stackTrace: [com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39), com.avaje.tests.query.TestPagingListLoop.test(TestPagingListLoop.java:20), sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method), sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39), sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)]
Possible Leaked Connection: name[h2.1] stackTrace: [com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39), com.avaje.tests.query.TestPagingListLoop.test(TestPagingListLoop.java:20), sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method), sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:39), sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25)]
17/03/2010 05:17:48 com.avaje.ebeaninternal.server.lib.sql.PooledConnection closeConnectionFully
...

So there can be a lot dumped out.

Rob 17 Mar 05:33
So ...

So the stack trace points out where the connection was created (and never closed).

In the example above I have a connection pool leak in:

com.avaje.tests.query.TestPagingListLoop.createLeak(TestPagingListLoop.java:39)

Rob 17 Mar 05:42
Fixed in HEAD

Fixed in HEAD.

woResponse

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