Hi,
I like MINA for its simplicity and giving ability to the developers
for developing faster prototypes. Thanks for Apache-MINA team for such
a good project.
I am trying mina-0.9.4 for sending events @rate of 1000-2000/sec for a
prototype. Average event size is 200bytes(approx.). I am using
default obejct factory for serialization.
After 18 minutes at that rate(with two clients), I found mina server
is raising OutofMemoryError and heap-space problems.
Server(RH-9)/Client(Win2k) are P4 3.06 GHZ with 512 MB Ram. I am using
JDK 1.5.0_06
I tried to dig around the code and found the ByteBuffer.putObject has
following code:
--------------------- Original code -----------------------------
try
{
ObjectOutputStream out = new ObjectOutputStream( asOutputStream() )
{
protected void writeClassDescriptor( ObjectStreamClass
desc ) throws IOException
{
writeUTF( desc.getName() );
}
};
out.writeObject( o );
out.flush();
}
catch( IOException e )
{
throw new BufferDataException( e );
}
-------------------- Modified code ----------------------------
try
{
ObjectOutputStream out = new ObjectOutputStream( asOutputStream() )
{
protected void writeClassDescriptor( ObjectStreamClass
desc ) throws IOException
{
writeUTF( desc.getName() );
}
};
out.writeObject( o );
}
catch( IOException e )
{
throw new BufferDataException( e );
}finally{
// TODO do out.close() in separate thread. is it ok to
call in separate thread
out.close();// close will internally call flush and clear.
}
---------------------------------------------------------------------
The problem with ObjectOutputStream is well documented in web. One
good link is:
http://www.javaspecialists.co.za/archive/newsletter.do?issue=088&locale=en_US
In ByteBuffer.putObject, the ObjectOutputStream anyhow is going to be
garbage collected. But it seems for longer operations/large number of
calls, one needs to call reset/close on ObjectOutputStream to avoid a
memory leak. (http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=4363937)
My question are:
* Am I missing something ?
* Is this problem is faced by any body earlier ?
* If I donot want to call ObjectOutputStream.close in finally
block(to avoid latency on the ByteBuffer.putObject callee), can I
call it in separate Thread/pool ? Calling ObjectOutputStream.close in
separate thread later will cause any problems with ByteBuffer bytes.
TIA
GSS Mahadevan
