Max objects at the region level sets configures the memory manager.
http://jakarta.apache.org/jcs/RegionProperties.html If you use the indexed disk cache, then the MaxKeySize setting on that auxiliary, configures the number of disk indexes that the disk can have. http://jakarta.apache.org/jcs/IndexedDiskCacheProperties.html This configuration limits the memory cache to 10 and the disk cache to 1000 keys: ############################################################## ##### Default Region Configuration jcs.default=DC jcs.default.cacheattributes=org.apache.jcs.engine.CompositeCacheAttribut es jcs.default.cacheattributes.MaxObjects=10 jcs.default.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory .lru.LRUMemoryCache ############################################################## ##### AUXILIARY CACHES # Indexed Disk Cache jcs.auxiliary.DC=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheF actory jcs.auxiliary.DC.attributes=org.apache.jcs.auxiliary.disk.indexed.Indexe dDiskCacheAttributes jcs.auxiliary.DC.attributes.DiskPath=target/test-sandbox/indexed-disk-ca che jcs.auxiliary.DC.attributes.MaxPurgatorySize=500 jcs.auxiliary.DC.attributes.MaxKeySize=1000 jcs.auxiliary.DC.attributes.MaxRecycleBinSize=300 ________________________________ From: Joshua Fuller [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 20, 2005 3:16 PM To: Smuts, Aaron Cc: JCS Users List Subject: Re: Limiting Disk Cache Size? I'm sorry I seem so confused on this - but I think it must come from a misunderstanding of how the disk cache is used in the first place. The site says "When the memory cache exceeds its maximum size it tells the cache hub that the item to be removed from memory should be spooled to disk." What is the "maximum size" then that is being referred to? I was under the impression it was the "jcs.default.cacheattributes.MaxObjects" value, but that does not seem to make sense now either. Can you clarify what values do what in regards to disk cache? If I want 10 items in memory, and 1000 items on disk in my cache - how can I do that? Thanks, Josh Fuller On 9/20/05, Smuts, Aaron <[EMAIL PROTECTED]> wrote: ________________________________ From: Joshua Fuller [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 20, 2005 12:40 PM To: Smuts, Aaron Cc: JCS Users List Subject: Re: Limiting Disk Cache Size? Thanks for your quick response and help. So would you recommend setting up multiple disk cache, and using the MaxKeySize value to limit it? Or is your last statement saying that the MaxKeySize will not actually limit the size of objects on the disk anyway, but only the number of keys in memory? The indexec disk cache is a memory index of items on disk. The keys and the starting location of on disk for an item are stored in memory. The maxkeysize on the disk cache limits the number of keys stored in the index. This has nothing to do with the max size setting on the memory cache. So to clarify, if I have a database of 100,000 records that are heavily used - and I have a cache setup with a MaxKeySize of 1,000 - then there is nothing preventing all 100,000 records from being spooled to disk as long as they have yet to expire? Yes and no. All of them can get spooled, but only 1000 will be available. A follow-up question to that would be - Does the memory shrinker thread get used also to clean up the disk cache items that may have expired, or how do they get cleaned out? Nope. It is just a memory cache shrinker. They get cleaned out when remove is called. Remove is called when you call remove or when you call get and an item is found to be expired. Thanks, Josh Fuller On 9/20/05, Smuts, Aaron <[EMAIL PROTECTED]> wrote: You can only limit the number of keys, not the size of the file. The disk cache keeps track of empty spots from where an item has been removed and it tries to reuse them, but this doesn't stop it from growing indefinitely if you keep putting larger and larger items on disk. I don't think that the disk cache marks a spot as available when a key is spooled off the disk cache key lru. . . . > -----Original Message----- > From: Joshua Fuller [mailto: [EMAIL PROTECTED] <mailto:[EMAIL PROTECTED]> ] > Sent: Monday, September 19, 2005 9:07 PM > To: jcs-users@jakarta.apache.org > Subject: Fwd: Limiting Disk Cache Size? > > Sorry, if this is a repeat - the last email didnt seem to send so I'm > trying > again...... > > Is there a way to limit the size of the items in the cache being stored to > disk for a given region, or even globally? I can't find any setting > anywhere > that limits the size of the files on disk (by number of elements or > physical). > > Thanks, > Josh Fuller
