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From "James Strachan" <>
Subject Re: 4.0 Consumer OutOfMemoryError bug?
Date Wed, 14 Jun 2006 13:32:07 GMT
On 6/13/06, jevans12 <> wrote:
> Are prefetch policy and optimized ack's Autonomous?

Yes, they are independent features. Prefetch policy is the maximum
number of unacknowledged messages delivered to a client by the broker.

optimized ack is an option to delay sending individual acks but send batches.

> As I see a consumer will
> ask for 65% of the prefetch policy messages.

The broker sends the entire prefetch size of messages to a client as
fast as possible; the client doesn't ask for messages per se - other
than subscribing with a prefetch value.

>  Does the batching of ack's
> follow this? as I receive the 65th (of 100) message a batch ack will be sent
> for those 65?

I'd have to noodle around the code but yes if enabled then optimize
acks sends in batches.

Though folks have experienced some problems with optimize acks...

so it might be worth disabling them (I've added this to the 4.0 release notes).



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