[infinispan-dev] Eviction maxEntries analysis

[Vladimir Blagojevic]

Martin,

There will always be "problems" around sizing in these small containers. 
I think we are all aware of it now, what is more important is that 
eviction works properly in all other scenarios! I am ok with this!

Regards,
Vladimir

On 12-02-03 11:59 AM, Martin Gencur wrote:
> 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)
>>
>>
>>