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From Gary Tully <>
Subject Re: Incremental updates and QueryBasedSubscriptionRecoveryPolicy
Date Tue, 03 May 2011 09:47:31 GMT
your recovery policy will be hit N times, it is up to the query to
cache the messages as it pleases. The only concrete implementation I
see is in the tests so it looks like it is up to you.

On 30 April 2011 14:52, this.juan <> wrote:
> Hi,
> This is what I'd like to do:
> * Clients subscribe to a Topic, when the client starts they need first to
> receive a initial message (current state of some data in the producer). With
> this initial message in place, its enough to receive incremental updates of
> the data.
> * The initial message is expensive (in size).
> * The incremental updates are small but frequent.
> I've read about the QueryBasedSubscriptionRecoveryPolicy where I can
> override a method in a MessageQuery to get this initial message. However,
> what would happen if N clients try to subscribe to the topic at the *same*
> time, will the producer get hit N times? Or does the broker cache the
> initial message?
> It's not clear to me how the recovery policy works in the broker in this
> kind of situation. In my case the producer will be busy processing (which
> result in the incremental updates), so with many consumer starting
> frequently, it may not be able to respond fast enough.
> --
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