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

Aaron Smuts

2010-04-22 13:41:25 UTC

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

Subject: [jira] Created: (JCS-73) concurrent cache access causes values loss
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
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
//
def
n = 5

while (n-- > 0) {

res = cache.getFromGroup(idx-1, group)

if (res) {

// the value finally appeared in
cache

${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}
{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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