Notwithstanding the OP’s issue …  is there any sensible way of preventing this?  Ie. how to detect connections are being returned to the pool without them properly ending transactions?


Is it even possible?




From: Clinton Begin []
Sent: Tuesday, March 06, 2007 6:40 PM
Subject: Re: What is RequestScope used for?


Yep, you have a leak and it is RequestScope related...but it's likely not an ibatis bug...

It's more likely that you're not ending transactions properly.

try {
  ///... do work
} finally {


On 3/6/07, Kalcevich, Daniel <> wrote:

OK, upon looking at the Yourkit, I am showing the number of objects in memory as the following:


-          com.ibatis.sqlmap.engine.impl.SqlMapClientImpl – 212 objects with a total retained size in memory of 31.38MB

-          com.ibatis.sqlmap.engine.scope.RequestScope – 108, 544 objects with a total retained size in memory of 16.49MB.

-          com.ibatis.sqlmap.engine.scope.SessionScope – 27,136 objects with a total retained size in memory of 3.03 MB.


Do those numbers make sense?  I only question it because with every snapshot of the memory I have taken along the way, the RequestScope/SessionScope objects keep increasing.




From: Kalcevich, Daniel
Sent: Tuesday, March 06, 2007 7:04 AM
To: ''
Subject: RE: What is RequestScope used for?


I found about this RequestScope through the profiler YourKit.  Here is the trail that references the IBatis objects.


map of com.ibatis.sqlmap.engine.scope.RequestScope

--[121] of java.lang.Object[513]

---elementData of java.util.ArrayList

----list of java.util.Collections$SynchronizedRandomAccessList

-----pool of com.ibatis.common.util.ThrottledPool

------requestPool of com.ibatis.sqlmap.engine.impl.SqlMapExecutorDelega te

------delegate of com.ibatis.sqlmap.engine.impl.SqlMapClientImpl

-------client of com.ibatis.dao.engine.transaction.sqlmap.SqlMapDao TransactionManager

--------transactionManager of com.ibatis.dao.engine.impl.DaoContext

---------[0] of java.lang.Object[11]

----------elementData of java.util.ArrayList

-----------value of java.lang.ThreadLocal$ThreadLocalMap$Entry

------------[1442] of java.lang.ThreadLocal$ThreadLocalMap$Entry[2049]

-------------table of java.lang.ThreadLocal$ThreadLocalMap

--------------threadLocals of java.lang.Thread [Stack Local, Thread]



The reason I thought it might be contributing to a memory leak was the fact that at every snapshot I take, the number of HashMaps continues to increase without going down.  Then when I look at what it is referring to, it points to the RequestScope.


While looking in the trace, I saw that it was referencing the DaoContext's transaction Manager.  Could the Transaction Manager be playing a part in this?  My application uses Spring with SQL Maps, but a library we wrote uses the DAO Framework specifically.  The Spring application does not use it.  I think that is worth looking into, given what I see in the profiler.





From: Kalcevich, Daniel
Sent: Monday, March 05, 2007 11:37 AM
To: ''
Subject: What is RequestScope used for?




I have a Spring, Struts, SQL Map application that runs on JBoss/Tomcat.  And while going through a profiler, I am seeing that there are several instances of "com.ibatis.sqlmap.engine.scope.RequestScope".  What is that object used for?  The reason I ask is that I am trying to track down a memory leak and am wondering if this class is possibly part of the cause?  Any help is greatly appreciated.  Thank you.