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From "Hanson Char" <hanson.c...@gmail.com>
Subject Re: HELP - very weird behaviour
Date Thu, 24 Aug 2006 23:37:51 GMT
Can GC, heap memory min/max sizes, and the GC throughput target be
some factors ?  What JVM are you running on ?  If Java 5, you can try
some of these JVM parameters:

-server for server mode
-verbose:gc to find out more about what the GC is doing
-XX:+UseParallelGC for concurrent GC
-XX:GCTimeRatio=19 for the target throughput rate (default is 99)
-Xms512m -Xmx512m  for the min/max heap memory size

For example:

java -server -verbose:gc -XX:+UseParallelGC -XX:GCTimeRatio=19
-Xms512m -Xmx512m Main

My 2 cents.

Hanson

On 8/24/06, Vladimir Olenin <VOlenin@cihi.ca> wrote:
> Hi,
>
> I'm using the following configuration:
>
> ----------------------------
> jcs.default=DC
> jcs.default.cacheattributes=org.apache.jcs.engine.CompositeCacheAttribut
> es
> jcs.default.cacheattributes.MaxObjects=1000
> jcs.default.cacheattributes.MemoryCacheName=org.apache.jcs.engine.memory
> .lru.LRUMemoryCache
>
>
> # AVAILABLE AUXILIARY CACHES
> 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=./temp
> jcs.auxiliary.DC.attributes.maxKeySize=100000
> jcs.auxiliary.DC.attributes.MaxPurgatorySize=100000
> ------------------------
>
> The weird thing is that the entries retrieval performance degrades when
> 'jcs.default.cacheattributes.MaxObjects' grows. I assumed it should be
> the other way around. When I set this value to '10000' and put not more
> than '10000' entries in cache, the jcs.get(key) start to CRAWL!!!
> (returns within 2-3 seconds) with CPU consumption at 100%. The 'data'
> and 'key' files are empty, which seems to prove that all entries are
> contained in memory and nothing has been swapped to HD.
>
> When that setting is at '10', 'data' and 'key' files are growing to
> several megs (with my data), which seem to prove that almost all entries
> are swaped to HD, while jcs.get() call returns within serveral
> milliseconds.
>
> What am I doing wrong?...
>
> Thanks.
>
> Vlad
>
>

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