Hi David,
I'll give it a whirl!
cheers,
Rob
On Feb 5, 2008, at 9:28 PM, David Sitsky wrote:
Hi,
In my application using the current trunk version, I was finding
that my queue subscriptions had huge pending message cursors sizes
(> 70,000 and growing) - essentially they were equal to
enqueueCounter - dispatchCounter which I could see from JMX.
It seems like a simple optimisation could be to remove a node from
the cursor if has been dropped when we call dispatchPending(). This
made a gigantic difference in speed, since the broker wasn't
iterating over a huge number of dropped messages, and locks were
held for a shorter period of time. Not to mention, less memory and
CPU will be consumed by the broker.
Here is the patch below - I don't know if it is safe in general, but
it seemed to work fine for me.
Cheers,
David
Index: activemq-core/src/main/java/org/apache/activemq/broker/region/
PrefetchSubscription.java
===================================================================
--- activemq-core/src/main/java/org/apache/activemq/broker/region/
PrefetchSubscription.java (revision 618650)
+++ activemq-core/src/main/java/org/apache/activemq/broker/region/
PrefetchSubscription.java (working copy)
@@ -453,7 +461,11 @@
if (node == null) {
break;
}
- if (canDispatch(node)) {
+ else if (((QueueMessageReference)node).isDropped())
+ {
+ pending.remove();
+ }
+ else if (canDispatch(node)) {
pending.remove();
// Message may have been sitting in
the pending
// list a while waiting for the
consumer to ak the message.
