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Posted to dev@sling.apache.org by Ben Zahler <be...@inside-solutions.ch> on 2014/07/29 08:15:33 UTC
Idea: Caching in Sling
Hi all,
We are considering to implement a resource-based caching in Sling.
I have found some efforts to do something similar in the past, but they all seem to have been either abandoned or do something different from what we have in mind.
So it would be great to get some feedback if it this has been tried before and was given up or if our idea is just not what the Sling-world is waiting for.
This is what our Sling-Cache would do:
- deliver sling resources from cache based on an exact path
- deliver sling resources from cache for a subtree of the repository
The following scenarios would benefit from such a cache:
- navigation components that are expensive to calculate and are identical for whole subtrees of a site
- cacheable components on non-caheable pages
- CQ use cases with dispatcher caching invalidate the large sections or the whole cache. After an invalidation, for a short time all traffic hits CQ/Sling. With resource based caching, this could be improved, allowing Sling to scale better.
Of course we would create an open-source implementation of our idea, caching either in memory or in the repository itself and leave room for other implementations with external caches.
So is this an idea you would love to see implemented or is it rather something that you deem unnecessarily complex?
Thanks for any feedback!
Cheers,
Ben Zahler
Inside Solutions AG | Bahnhofplatz 11 | 4410 Liestal | Schweiz
Telefon: +41 61 551 00 40 | Direkt: +41 61 551 00 43
http://www.inside-solutions.ch<http://www.inside-solutions.ch/>
Re: Idea: Caching in Sling
Posted by Nicolas Peltier <np...@adobe.com>.
Hi Ben,
Jackrabbit used to come with bundle cache which does exactly what you say, not knowing anything about the tree structure. And that stupidity is its strength: no need for a smart developer
to do pin point configuration of a tree or a single path. Things that are really used a lot were cached, the only configuration you do is on the size of the cache. I’m pretty sure similar mechanism exists with oak.
Now helping the stupid persistence caching by caching at the “application” layer things you, as an application developer, know they will be used a lot is always a good idea. Not sure this needs a framework though.
Nicolas
On 29 Jul 2014, at 08:15, Ben Zahler <be...@inside-solutions.ch> wrote:
> Hi all,
>
> We are considering to implement a resource-based caching in Sling.
>
> I have found some efforts to do something similar in the past, but they all seem to have been either abandoned or do something different from what we have in mind.
>
> So it would be great to get some feedback if it this has been tried before and was given up or if our idea is just not what the Sling-world is waiting for.
>
> This is what our Sling-Cache would do:
>
> - deliver sling resources from cache based on an exact path
>
> - deliver sling resources from cache for a subtree of the repository
>
> The following scenarios would benefit from such a cache:
>
> - navigation components that are expensive to calculate and are identical for whole subtrees of a site
>
> - cacheable components on non-caheable pages
>
> - CQ use cases with dispatcher caching invalidate the large sections or the whole cache. After an invalidation, for a short time all traffic hits CQ/Sling. With resource based caching, this could be improved, allowing Sling to scale better.
>
> Of course we would create an open-source implementation of our idea, caching either in memory or in the repository itself and leave room for other implementations with external caches.
>
> So is this an idea you would love to see implemented or is it rather something that you deem unnecessarily complex?
>
> Thanks for any feedback!
>
> Cheers,
> Ben Zahler
>
> Inside Solutions AG | Bahnhofplatz 11 | 4410 Liestal | Schweiz
> Telefon: +41 61 551 00 40 | Direkt: +41 61 551 00 43
> http://www.inside-solutions.ch<http://www.inside-solutions.ch/>
Re: Idea: Caching in Sling
Posted by Ruben Reusser <rr...@headwire.com>.
Ben,
we chose a bit of a different approach and added html caching for CQ a
while back
http://www.headwire.com/svn/projects/cqbpcache/trunk/cqbpcache/
basically,we use a tag that allows you to monitor changes in a path and
cache the html accordingly until a node in the path (or one if its
subnodes) changes.
Feel free to try it out, feedback welcome
Ruben
On 7/28/2014 11:15 PM, Ben Zahler wrote:
> Hi all,
>
> We are considering to implement a resource-based caching in Sling.
>
> I have found some efforts to do something similar in the past, but they all seem to have been either abandoned or do something different from what we have in mind.
>
> So it would be great to get some feedback if it this has been tried before and was given up or if our idea is just not what the Sling-world is waiting for.
>
> This is what our Sling-Cache would do:
>
> - deliver sling resources from cache based on an exact path
>
> - deliver sling resources from cache for a subtree of the repository
>
> The following scenarios would benefit from such a cache:
>
> - navigation components that are expensive to calculate and are identical for whole subtrees of a site
>
> - cacheable components on non-caheable pages
>
> - CQ use cases with dispatcher caching invalidate the large sections or the whole cache. After an invalidation, for a short time all traffic hits CQ/Sling. With resource based caching, this could be improved, allowing Sling to scale better.
>
> Of course we would create an open-source implementation of our idea, caching either in memory or in the repository itself and leave room for other implementations with external caches.
>
> So is this an idea you would love to see implemented or is it rather something that you deem unnecessarily complex?
>
> Thanks for any feedback!
>
> Cheers,
> Ben Zahler
>
> Inside Solutions AG | Bahnhofplatz 11 | 4410 Liestal | Schweiz
> Telefon: +41 61 551 00 40 | Direkt: +41 61 551 00 43
> http://www.inside-solutions.ch<http://www.inside-solutions.ch/>
>
Re: Idea: Caching in Sling
Posted by Jörg Hoh <jh...@googlemail.com>.
Hi Ben,
sounds good, although there are some things to consider when implementing
it (for the general case; for a very narrow case you don't need to
implement them all):
* ACLs: Depending on the user requesting items from the cache a cached item
could be retrieved or not. Also consider the case, that you cache larger
entities although the backing JCR contains ACLs on a more granular level.
* The benefit is probably rather low if you just cache read resources in
memory, you should be able to cache also multiple higher-level objects for
a resource in that cache (e.g. HTML fragments). If you want to avoid
hitting the disk, I would increase the bundleCacheSize (JR 2.x) or increase
the amount of free usable RAM (Oak).
I guess, that you can [1] as basis for it. A bonus would be if you could
inject sling model objects directly from this cache with just a single
annotation ;-)
Jörg
[1] http://sling.apache.org/documentation/bundles/caching-services.html
2014-07-29 8:15 GMT+02:00 Ben Zahler <be...@inside-solutions.ch>:
> Hi all,
>
> We are considering to implement a resource-based caching in Sling.
>
> I have found some efforts to do something similar in the past, but they
> all seem to have been either abandoned or do something different from what
> we have in mind.
>
> So it would be great to get some feedback if it this has been tried before
> and was given up or if our idea is just not what the Sling-world is waiting
> for.
>
> This is what our Sling-Cache would do:
>
> - deliver sling resources from cache based on an exact path
>
> - deliver sling resources from cache for a subtree of the repository
>
> The following scenarios would benefit from such a cache:
>
> - navigation components that are expensive to calculate and are
> identical for whole subtrees of a site
>
> - cacheable components on non-caheable pages
>
> - CQ use cases with dispatcher caching invalidate the large sections
> or the whole cache. After an invalidation, for a short time all traffic
> hits CQ/Sling. With resource based caching, this could be improved,
> allowing Sling to scale better.
>
> Of course we would create an open-source implementation of our idea,
> caching either in memory or in the repository itself and leave room for
> other implementations with external caches.
>
> So is this an idea you would love to see implemented or is it rather
> something that you deem unnecessarily complex?
>
> Thanks for any feedback!
>
> Cheers,
> Ben Zahler
>
> Inside Solutions AG | Bahnhofplatz 11 | 4410 Liestal | Schweiz
> Telefon: +41 61 551 00 40 | Direkt: +41 61 551 00 43
> http://www.inside-solutions.ch<http://www.inside-solutions.ch/>
>
--
Cheers,
Jörg Hoh,
http://cqdump.wordpress.com
Twitter: @joerghoh