Re: [jira] Created: (JCS-73) concurrent cache access causes values loss

[Aaron Smuts <as...@yahoo.com>]

The group functionality will be deprecated.  It's already unofficially deprecated.  Most of the auxiliaries don't support it.  . . . But I look into it.

Aaron

--- On Wed, 4/14/10, Alexander Kleymenov (JIRA) <ji...@apache.org> wrote:

> From: Alexander Kleymenov (JIRA) <ji...@apache.org>
> Subject: [jira] Created: (JCS-73) concurrent cache access causes values loss
> To: jcs-dev@jakarta.apache.org
> Date: Wednesday, April 14, 2010, 9:27 PM
> concurrent cache access causes values
> loss
> ------------------------------------------
> 
>              
>    Key: JCS-73
>              
>    URL: https://issues.apache.org/jira/browse/JCS-73
>          
>    Project: JCS
>           Issue Type: Bug
>           Components: Indexed Disk
> Cache
>     Affects Versions: jcs-1.3
>             Reporter:
> Alexander Kleymenov
>             Assignee: Aaron
> Smuts
> 
> 
> The following groovy code demonstrates the problem: several
> threads write to the cache and try to read previously
> written values. Sometimes values can be retrieved. In this
> case, subsequent tries can get the value, but not always.
> {code}
> cache = org.apache.jcs.JCS.getInstance("cache")
> group = "group"
> worker = {
>     def name = Thread.currentThread().name
>     10000.times { idx ->
>         if (idx) {
>             // get previously
> stored value
>             def res =
> cache.getFromGroup(idx-1, group)
>             if (!res) {
>                 //
> null value got inspite of the fact it was placed in cache!
>                
> println "ERROR: for ${idx} in " + name
>                 //
> try to get the value again:
>                 def
> n = 5
>                
> while (n-- > 0) {
>                
>     res = cache.getFromGroup(idx-1, group)
>                
>     if (res) {
>                
>         // the value finally appeared in
> cache
>                
>         println "ERROR FIXED for ${idx}:
> ${res} " + name
>                
>         break
>                
>     }
>                
>     println "ERROR STILL PERSISTS for ${idx} in "
> + name
>                
>     Thread.sleep(1000)
>                 }
>             }
>         }
>         // put value in the cache
>         cache.putInGroup(idx, group,
> [value:[a:1, b:2, c:3], aux:[1:'a', 2:'b', 3:'c', t:name]])
>         if (!(idx % 10000)) {
>             println name+"
> "+idx
>         }
>     }
> }
> 
> Thread.start worker
> Thread.start worker
> Thread.start worker
> Thread.start worker
> Thread.start worker
> Thread.start worker
> Thread.start worker
> Thread.start worker
> {code}
> 
> Cache configuration:
> {code}
> jcs.default=CACHE
> jcs.default.cacheattributes=org.apache.jcs.engine.CompositeCacheAttributes
> jcs.default.cacheattributes.MaxObjects=-1
> jcs.default.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory.lru.LRUMemoryCache
> jcs.default.cacheattributes.DiskUsagePatternName=UPDATE
> jcs.default.cacheattributes.UseMemoryShrinker=true
> jcs.default.cacheattributes.MaxMemoryIdleTimeSeconds=10
> jcs.default.cacheattributes.ShrinkerIntervalSeconds=10
> jcs.default.elementattributes=org.apache.jcs.engine.ElementAttributes
> jcs.default.elementattributes.IsRemote=false
> jcs.default.elementattributes.IsLateral=false
> jcs.default.elementattributes.IsSpool=true
> jcs.default.elementattributes.IsEternal=true
> 
> jcs.auxiliary.CACHE=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheFactory
> jcs.auxiliary.CACHE.attributes=org.apache.jcs.auxiliary.disk.indexed.IndexedDiskCacheAttributes
> jcs.auxiliary.CACHE.attributes.DiskPath=./cache
> jcs.auxiliary.CACHE.attributes.MaxPurgatorySize=-1
> jcs.auxiliary.CACHE.attributes.MaxKeySize=-1
> jcs.auxiliary.CACHE.attributes.MaxRecycleBinSize=500
> jcs.auxiliary.CACHE.attributes.ShutdownSpoolTimeLimit=60
> jcs.auxiliary.CACHE.attributes.OptimizeAtRemoveCount=30000
> jcs.auxiliary.CACHE.attributes.OptimizeOnShutdown=true
> jcs.auxiliary.CACHE.attributes.EventQueueType=SINGLE
> {code}
> 
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