[infinispan-dev] Eviction maxEntries analysis

[Martin Gencur]

I see, for the bigger numbers entries are evicted (more than just to
decrease the number to maxEntries) before I actually check the number so
this is expected. For the 2,4,6,8,10 eviction did not run so the cache
contains more than maxEntries. Are we OK with that?

Thanks


M.


On Fri, 2012-02-03 at 15:29 +0100, Martin Gencur wrote:
> Hi all,
> I ran a few tests to find out what is the actual number of entries held
> in a cache when certain "maxEntries" param is set for eviction and I
> store more than maxEntries entries. I tested with HotSpot JDK6 [1], IBM
> JDK 6,7 [2]. OpenJDK6 seems to have the same results as HotSpot JDK. 
> 
> Results:
> 
> maxEntries being set -> actual number of entries held in the cache
> 
> HotSpot JDK:
> ------------
> 
> 2 -> 2
> 4 -> 4
> 6 -> 4
> 8 -> 8
> 10 -> 8
> 256 -> 232
> 300 -> 266
> 
> IBM JDK (both 6, 7):
> --------------------
> 
> 2 -> 4 (2 with LIRS)
> 4 -> 6 (4 with LIRS)
> 6 -> 10 
> 8 -> 11 (8 with LIRS)
> 10 -> 13, (8 with LIRS)
> 300 -> 287, (266 with LIRS)
> 256 -> 247, (232 with LIRS)
> 
> I modified one test in ispn-core to do this testing:
> https://github.com/mgencur/infinispan/commit/837a1c752fa7fbfb3f05738dd873e78cbf71d071
> 
> 
> 
> Any thoughts ? :)
> 
> 
> 
> [1] 
> 
> java version "1.6.0_21"
> Java(TM) SE Runtime Environment (build 1.6.0_21-b06)
> Java HotSpot(TM) 64-Bit Server VM (build 17.0-b16, mixed mode)
> 
> [2]
> 
> java version "1.6.0"
> Java(TM) SE Runtime Environment (build pxi3260sr9fp1-20110208_03(SR9
> FP1))
> IBM J9 VM (build 2.4, JRE 1.6.0 IBM J9 2.4 Linux x86-32
> jvmxi3260sr9-20110203_74623 (JIT enabled, AOT enabled)
> 
> java version "1.7.0"
> Java(TM) SE Runtime Environment (build pxi3270-20110827_01)
> IBM J9 VM (build 2.6, JRE 1.7.0 Linux x86-32 20110810_88604 (JIT
> enabled, AOT enabled)
> 
> 
> 

-- 
Martin Gencur
--
JBoss QE, Enterprise Data Grid
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