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From Felix Meschberger <fmesc...@gmail.com>
Subject Re: [jr3] MicroKernel prototype
Date Wed, 17 Mar 2010 10:11:40 GMT

On 17.03.2010 10:34, Thomas Müller wrote:
> Hi,
>> In your opinion, which part make the most of performance contribution?
> It's hard to say. I would rather spend my time to work on the
> prototype than to find out.

Agreed. And at the end of the day, it is probably not very interesting
given that the new architecture should start from scratch and not try to
enhance the existing.

> To keep the prototype fast, it's important
> to always check performance.

This is a dangerous sentence as it gives way to premature optimization ;-)

> I guess we didn't always do that for
> Jackrabbit unfortunately. By the way, if you use a slower persistence
> layer then the gain will be much less.

I think the approach to Jackrabbit 3 must be first and foremost to come
up with a clean and easy to understand architecture. This is much more
important than raw performance.

Once you have an implementation based on a clear architecture, you can
analyze where you can loose weight.

(and yes I know it is not black and white and performance must be kept
in mind, it must not be the first goal)


>> Does prototype have similar cache size.
> Both Jackrabbit and the prototype use about 20 MB at the end of the
> run. The prototype uses a weak reference map (so does the current
> Jackrabbit as far as I know) and doesn't have to read data from the
> persistence layer. The current Jackrabbit does read, not sure why. If
> I disable this cache in the prototype, the test takes 0.24 seconds
> instead of 0.2 seconds.
> Regards,
> Thomas

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