Hi Denis,

Yes we don't need to have expiration policy, so setting
CacheConfiguraiton.setEagerTtl to false solved this problem.

So we are testing the whole system, we also found out that using a cache
with writeBehind enabled causes a new thread creation for each one. So if
we think about future plans and possibilities, it's not a best practice to
have increasing number of threads within jvm.

We wonder that if there is a option to use a thread pool for writeBehind
jobs. If there is not, we could implement it for the community. So if you
can guide us where to start, i would be glad :)

Thanks.

On Fri, Apr 8, 2016 at 1:54 AM, Denis Magda <[email protected]> wrote:

> Tolga,
>
> The cleanup threads "ttl-cleanup-workers" are used to eagerly remove
> expired cache entries. Expiration policy can be set either a cache wide in
> CacheConfiguration or can be used later with cache.withExpirePolicy(...)
> calls.
> I failed to reproduce your case. What I've done is started 30 caches and
> destroyed all of them later. Visual VM showed that all
> "ttl-cleanup-workers" were stopped successfully.
> What Ignite version do you use?
>
> In any case if you are not planing to use expiration policy you can set
> CacheConfiguraiton.setEagerTtl to false and the ttl workers Threads won't
> be created at all.
>
> Regards,
> Denis
>
>
> On 4/7/2016 3:43 PM, Tolga Kavukcu wrote:
>
> Hi Denis,
>
> IGNITE_ATOMIC_CACHE_DELETE_HISTORY_SIZE parameter seems like decreased
> heap usage. I will run longer tests to check heap behaviour.
>
> Also i need another help with thread's created by ignite. I found out that
> ignite creates a cleanup thread named "ttl-cleanup-worker" for each cache.
> But when cache is destroyed, clean up thread does not deleted. Instead it
> waits sleeping state at all.
>
> My first question is that , is it possible to decrease thread count with a
> configuration, like "thread pool with x threads" for all caches.
> Secondly, is "unremoved threads" are expected behaviour.
>
> Thanks.
>
> On Thu, Apr 7, 2016 at 2:40 PM, Denis Magda <[email protected]> wrote:
>
>> Hi Tolga,
>>
>> GridDhtPartitionTopologyImpl is created per cache. If you destroy a cache
>> this object should be GCed. However you should use cache.destroy() for that.
>>
>> Please also make sure that you make "live set" heap dumps only. Try to
>> perform GC explicitly before making the dump because a collector may clean
>> dead objects much later depending on its heuristics.
>>
>> --
>> Denis
>>
>> On 4/7/2016 8:27 AM, Tolga Kavukcu wrote:
>>
>> Hi Denis,
>>
>> Thanks for the response. I will try IGNITE_ATOMIC_CACHE_DELETE_HISTORY_SIZE 
>> parameter.
>> The screnshots taken from eclipse memory analyser which opens and analyses
>> heap dump. I understand heap requirement for wrapping and indexing off-heap
>> entry positions. But also found out that instances of 
>> *org.apache.ignite.internal.processors.cache.distributed.dht.GridDhtPartitionTopologyImpl
>> *is constantly increasing within jvm.
>>
>>
>> I also create and destroy so many small caches during the lifecycle, do
>> you think that it is possible to destroyed caches leaves a footprint in
>> heap.
>>
>> The previous scrreenshots was dominator tree view of memory analyser. I
>> attached again with headers.
>>
>>  You can see that each of GridDhtPartitionTopologyImpl uses 20mb~ heap.
>> And there are 72 instances of GridDhtPartitionTopologyImpl living.
>>
>> Also i attached screenshots of leak suspect report of memory analyzer,
>> which is taken periodically. You an see that instances of 
>> *GridDhtPartitionTopologyImpl
>> keeps increasing. *
>>
>> Any ideas or suggestions?
>>
>> On Wed, Apr 6, 2016 at 6:00 PM, Denis Magda < <[email protected]>
>> [email protected]> wrote:
>>
>>> Hi Tolga,
>>>
>>> GridDhtPartitionTopologyImpl contains list of partitions that belong to
>>> a specific node. In case of offheap caches each partition (concurrent map)
>>> contains set of wrappers around keys->values, stored offheap. The wrapper
>>> holds information that's needed to unswap a value or a key to Java heap
>>> from offheap when required by a user application.
>>> So Ignite requires extra space for internal needs even when offheap mode
>>> is used.
>>>
>>> I would recommend you trying to reduce
>>> IgniteSystemProperties.IGNITE_ATOMIC_CACHE_DELETE_HISTORY_SIZE. This is the
>>> size of the queue that keeps deleted entries for internal needs as well.
>>> https://apacheignite.readme.io/v1.5/docs/capacity-planning
>>>
>>> BTW, could you explain what columns from your screenshot mean exactly?
>>> What tool did you use to create the memory snapshot?
>>>
>>> --
>>> Denis
>>>
>>>
>>>
>>> On 4/6/2016 3:02 PM, Tolga Kavukcu wrote:
>>>
>>> Hi everyone,
>>>
>>> I use partitioned ignite cache for a very dynamic data. Means that there
>>> are many updates,deletes and puts with around 5m~ row.
>>>
>>> So to avoid gc pauses i use off-heap mode. But when i analyse heap i see
>>> that count and heap size of
>>> *org.apache.ignite.internal.processors.cache.distributed.dht.GridDhtPartitionTopologyImpl*
>>>  is
>>> increasing constantly.
>>>
>>> Please see attached screenshots taken from mat heap dump.
>>>
>>> <bean class="org.apache.ignite.configuration.CacheConfiguration" 
>>> name="DEFAULT">    <property name="atomicityMode" value="ATOMIC" />    
>>> <property name="cacheMode" value="PARTITIONED" />    <property 
>>> name="memoryMode" value="OFFHEAP_TIERED" />    <property name="backups" 
>>> value="1" />    <property name="affinity">        <bean 
>>> class="org.apache.ignite.cache.affinity.fair.FairAffinityFunction">         
>>>    <constructor-arg index="0" type="int" value="6"/>        </bean>    
>>> </property>    <property name="writeThrough" value="false" />    <property 
>>> name="writeBehindEnabled" value="false" /></bean>
>>>
>>> Thanks for helping out.
>>>
>>> There are totally 1.2 heap used by GridDhtPartitionTopologyImpl, almost
>>> equals to my data size. Do you think that there are problems with
>>> configuration.
>>>
>>>
>>> *Tolga KAVUKÇU *
>>>
>>>
>>>
>>
>>
>> --
>>
>> *Tolga KAVUKÇU *
>>
>>
>>
>
>
> --
>
> *Tolga KAVUKÇU *
>
>
>


-- 

*Tolga KAVUKÇU*

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