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From avim <avi.mor...@timetoknow.org>
Subject Re: node caching
Date Wed, 21 Mar 2007 10:19:46 GMT

Where can I find more information(general/specific) about about
JCR/Jackrabbit caches?

Stefan Guggisberg wrote:
> 
> On 3/19/07, Harry Moore <harry.moore@eyestreet.com> wrote:
>> So nodes are cached regardless of persistence manager? That is good to
> 
> yes, correct.
> 
>> know. Is it fixed size, most-recently-used?
> 
> item states (representing the raw node/property data) read from/written to
> the persistence layer are cached by an ItemStateReferenceCache instance:
> 
> http://jackrabbit.apache.org/api-1/org/apache/jackrabbit/core/state/ItemStateReferenceCache.html
> 
> the eviction policy is pluggable by design and currently hardcoded to
> use MLRUItemStateCache which is allocated a certain amount of memory.
> oldest entries are flushed once the cache size has exceeded this limit.
> 
> we've experimented with different eviction policies (LRU etc), the very
> simple
> current (FIFO) seems to be vey efficient overall.
> 
> just being curious: why did you ask for node caching in the first place?
> did you experience inadequate read performance?
> 
> cheers
> stefan
> 
>>
>> Harry
>>
>> Tobias Bocanegra wrote:
>> > hi,
>> > please note, that there are several layer of caching present in
>> > jackrabbit.
>> > there is a cache of the items of the itemmanager (session scope), a
>> > cache of the itemstates of the localeitemstatemanager (session scope),
>> > a cache of the itemstates in the shareditemstatemanager (global
>> > scope).
>> >
>> > there is no need for an additional caching.
>> > regards, toby
>> >
>> > On 3/17/07, Danner, Russ <DannerR@csps.com> wrote:
>> >>
>> >> what are the cons of that approach?  Is there a background thread
>> >> actually persisting the changes?  What happens when the machnine
>> >> fails for some reason? From the javadoc it looks like a bad option...
>> >> like a toy that one would use for testing (it says the class should
>> >> only be used for testing.)  Maybe it could be adapted to act as a
>> cache.
>> >>
>> >> -R
>> >>
>> >>
>> >>
>> >> -----Original Message-----
>> >> From: Harry Moore [mailto:harry.moore@eyestreet.com]
>> >> Sent: Fri 3/16/2007 10:45 PM
>> >> To: users@jackrabbit.apache.org
>> >> Subject: Re: node caching
>> >>
>> >> Looks like InMemPersistenceManager persistance is the way to go.
>> >>
>> >> Harry Moore wrote:
>> >> > Is there a way to flag a node, set of nodes or some other segment of
>> a
>> >> > jackrabbit repository for high-speed access? That is, cache
>> frequently
>> >> > accessed nodes in memory (with write-through update) so they can be
>> >> > accesses very quickly.
>> >> >
>> >> > Thanks,
>> >> >
>> >>
>> >> --
>> >> Harry Moore
>> >> Eye Street Software
>> >> Office: 888-252-2085 ext. 3013
>> >> Cell: 617-429-3666
>> >>
>> >>
>> >>
>> >
>> >
>>
>> --
>> Harry Moore
>> Eye Street Software
>> Office: 888-252-2085 ext. 3013
>> Cell: 617-429-3666
>>
>>
> 
> 

-- 
View this message in context: http://www.nabble.com/node-caching-tf3416916.html#a9590764
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