Purgatory is a queue on which items on the way to disk can still be accessed. Setting a limit on purgatory allows you to prevent the queue from getting too large. If you set a purgatory to 1000 and then quickly add 100,000 items faster than they can be written to disk, then the queue will certainly hit 1000. When the max purgatory size is reached the oldest are dropped.
Purgatory is basically a bounded queue with a map on top. There is a bit more description here: http://jakarta.apache.org/jcs/IndexedDiskAuxCache.html You should probably run with the cacheattributes properly called DiskUsagePatternName=UPDATE. This will cause the items to go to disk when they are added to the cache instead of when they fall out of the Memory cache. If you are going to flood the cache with items, then don't set a purgatory limit, or set it to the number you will be adding if it is known. Aaron --- Vladimir Olenin <[EMAIL PROTECTED]> wrote: > Hi. > > I need to configure JCS in the following manner: > > - need to load 100K entries into the cache > - NONE of the entries are allowed to be expired (ie, > ALL must be > eternal) > - have to keep in memory not more than 1000 entries > at a time > - the rest entries should be swapped to disk > automatically > > What is the default setting that would work the > best? The current > configuration I use is below and it seem to work. I > can't quite figure > out the meaning of 'MaxPurgatorySize' property. From > the docs I > understood that it's just the size of the 'disk > purge' queue. But the > tests show that if it's a positive number, then the > entries start to be > 'expired' from the cache (eg, if set to 1000 it > seems like only a small > fraction of 100K entries remains in cache and some > of the entries put in > the cache become missing for sure, since jcs.get > returns null). > > Thanks!. > > =========================================== > jcs.default = DC_SMALL_FOOTPRINT > jcs.default.cacheattributes = > org.apache.jcs.engine.CompositeCacheAttributes > jcs.default.cacheattributes.MaxObjects = 1000 > jcs.default.cacheattributes.MemoryCacheName = > org.apache.jcs.engine.memory.lru.LRUMemoryCache > > jcs.auxiliary.DC_SMALL_FOOTPRINT=org.apache.jcs.auxiliary.disk.indexed.I > ndexedDiskCacheFactory > jcs.auxiliary.DC_SMALL_FOOTPRINT.attributes=org.apache.jcs.auxiliary.dis > k.indexed.IndexedDiskCacheAttributes > jcs.auxiliary.DC_SMALL_FOOTPRINT.attributes.DiskPath=c:/Projects/Grouper > /temp/jcs > jcs.auxiliary.DC_SMALL_FOOTPRINT.attributes.maxKeySize=-1 > jcs.auxiliary.DC_SMALL_FOOTPRINT.attributes.MaxPurgatorySize=-1 > --------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
