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From Jukka Zitting <jukka.zitt...@gmail.com>
Subject Re: Kernel stats question.
Date Fri, 01 Mar 2013 07:19:57 GMT

On Thu, Feb 28, 2013 at 11:55 PM, Ian Boston <ieb@tfd.co.uk> wrote:
> Are there plans to expose kernel stats from Oak ?

Yes, see OAK-364 [1]. Though so far we haven't yet implemented
anything along these lines.

One related idea I was already thinking about implementing is exposing
cache statistics [2] from the Guava caches we're using at the
MicroKernel level.

> The Jackrabbit ObservationDispatcher has a queue that contains a
> AtomicInteger indicating the size of the queue. If Observers are slow
> in responding to asynchronous notifications the queue can grow
> rapidly.

This actually is an area that won't be an issue with Oak, as instead
of using a centralized queue from where events are pushed to observers
we're allowing each observer to generate events by comparing
successive repository revisions at their own pace. Thus one slow
observer will only block itself.

Of course there are other areas where such metrics will still be highly useful.

[1] https://issues.apache.org/jira/browse/OAK-364
[2] http://code.google.com/p/guava-libraries/wiki/CachesExplained#Statistics


Jukka Zitting

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