We are seeing thread local data being left on threads in the thread
pool of our application running in Tomcat 7 causing a memory leak.
This problem is not unique to us. The JIRA issues below are described
by your customers experiencing similar problems

https://jira.mongodb.org/browse/JAVA-596
https://jira.mongodb.org/browse/JAVA-130
https://jira.mongodb.org/browse/JAVA-236

In JAVA-236, the issue is closed but it does not address the issue.
The patch seems to miss the point: we want to free the TLS, not close
the connection.

Here is the patch we have introduced to your 2.9.10 distribution:

— src/main/com/mongodb/DBTCPConnector.java.orig 2012-12-03
12:39:49.000000000 -0700
+++ src/main/com/mongodb/DBTCPConnector.java 2012-12-11
08:04:11.000000000 -0700
@@ -608,6 +608,15 @@
}

/**
+ * Release thread local storage for invoking thread. This should
be called for threads
+ * in thread pools implemented as part of a web framework per
request. It is not required
+ * for the thread invoking close().
+ */
+ public void release()

+
+ /**