[ 
https://issues.apache.org/jira/browse/CASSANDRA-7438?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
 ]

Vijay updated CASSANDRA-7438:
-----------------------------

    Description: 
Currently SerializingCache is partially off heap, keys are still stored in JVM 
heap as BB, 

* There is a higher GC costs for a reasonably big cache.
* Some users have used the row cache efficiently in production for better 
results, but this requires careful tunning.
* Overhead in Memory for the cache entries are relatively high.

So the proposal for this ticket is to move the LRU cache logic completely off 
heap and use JNI to interact with cache. We might want to ensure that the new 
implementation match the existing API's (ICache), and the implementation needs 
to have safe memory access, low overhead in memory and less memcpy's (As much 
as possible).

We might also want to make this cache configurable.

  was:
Currently SerializingCache is partially off heap, keys are still stored in JVM 
heap as BB, 

* There is a higher GC costs for a reasonably big cache.
* Some users have used the row cache efficiently in production for better 
results, but this requires carful tunning.
* Overhead in Memory for the cache entries are relatively high.

So the proposal for this ticket is to move the LRU cache logic completely off 
heap and use JNI to interact with cache. We might want to ensure that the new 
implementation match the existing API's (ICache), and the implementation needs 
to have safe memory access, low overhead in memory and less memcpy's (As much 
as possible).

We might also want to make this cache configurable.


> Serializing Row cache alternative (Fully off heap)
> --------------------------------------------------
>
>                 Key: CASSANDRA-7438
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-7438
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Core
>         Environment: Linux
>            Reporter: Vijay
>            Assignee: Vijay
>             Fix For: 3.0
>
>
> Currently SerializingCache is partially off heap, keys are still stored in 
> JVM heap as BB, 
> * There is a higher GC costs for a reasonably big cache.
> * Some users have used the row cache efficiently in production for better 
> results, but this requires careful tunning.
> * Overhead in Memory for the cache entries are relatively high.
> So the proposal for this ticket is to move the LRU cache logic completely off 
> heap and use JNI to interact with cache. We might want to ensure that the new 
> implementation match the existing API's (ICache), and the implementation 
> needs to have safe memory access, low overhead in memory and less memcpy's 
> (As much as possible).
> We might also want to make this cache configurable.



--
This message was sent by Atlassian JIRA
(v6.2#6252)

Reply via email to