> -----Oorspronkelijk bericht----- > Van: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] Namens Michiel Meeuwissen > Verzonden: donderdag 12 mei 2005 17:08 > Aan: Discussion list for developers > Onderwerp: Re: [Developers] Roadmap features request > > > Ernst Bunders wrote: > > i think it would be a good idear to move towards a > pluggable caching > > system. Mmbase is used for a ever wider scope of solutions and the > > default caching (read multilevel cache). > > is just not sufficient for many applications (like forums, > polls, etc.). > > At vara we are removing some of these features from the > mmbase cloud for > > opimization (pity) for the busyest sites. > > to be able to create your own caches and configure them to handle > > certain data requests would be, gosh, just swell! > > I have some idears about it but they might be misguided, so > i would like > > to discuss them if people are interested > > > There is some movement on this areaa, since Pierre checked in a > 'CachePolicy', and months ago I already proposed a system for > pluggable > backings (which did not meet very much enthousiasm btw).
i did not read that. I have been away for a week and after that did not catch up on all 400.000 developer mail entries :) > > I think the 'query-caches' are quite good, but could be a bit > smarter. Perhaps we can also split them up (long lived, short lived > entries or so), and the CachePolicy can perhaps be used to > decide which > query is going in which cache. > > Correctness is quite important too, so it would suprize me a > bit that a > specialized cache could be much better then the Query-cache > implemetnation. But what actually would be your ideas? > well, i suppose the main thing that could vary is flushing rules/policy. for instance if i want to cache a forum, i want a mutable cache, that communicates it's changes to instances on other servers within the cluster through some messaging (not just flush, but update). This cash would be of a tree-like structure and perhaps would read query objects and map queries to specific entries in the cache tree, which could be more efficient (memorywise) than just caching all the queries on the forum. So mmbase would have to allow for inserting a cache somewhere in the storage layer before the database access. A cache would than descide if it wants to serve the data request or send it on to the db. I could even imagin a sort of caching pipeline (i mentioned this before) that all the queries are send thrue. every cache has it's own filter, and the nodecache and the multilevel cache would come last, as 'default' caches. I'm shure other spcialized cache types could be thought of that could greatly releave database traffic, and make mmbase more sutable for (very) dynamic websites (which it is not realy at the present) So what this boils down to is: -a formal insertion point for all caches (in the storage layer). possibly like a pipeline where caches pass on data requests they can not serve themselves, and where the caches are chained in a configured order. -some kind of mechanism would have to be in place to synchronize mutable caches. Another idear i have concerns the present multilevel cache. Would it not be a nice idear to cache only metadata in the multilevel cache, and refer for all the actual data to the nodecache? this way updates to specific nodes would not have to result into cache flushes anymore. Allso the multilevel cache could store many more queries becouse the memory useage would be very modest. Ernst > Michiel > > > > -- > Michiel Meeuwissen mihxil' > Mediacentrum 140 H'sum [] () > +31 (0)35 6772979 nl_NL eo_XX en_US > > > > _______________________________________________ > Developers mailing list > [email protected] > http://lists.mmbase.org/mailman/listinfo/developers > _______________________________________________ Developers mailing list [email protected] http://lists.mmbase.org/mailman/listinfo/developers
