> On 2012-04-24 20:53:33, Avery Ching wrote:
> > http://svn.apache.org/repos/asf/incubator/giraph/trunk/src/main/java/org/apache/giraph/comm/BasicRPCCommunications.java,
> >  lines 776-777
> > <https://reviews.apache.org/r/4852/diff/1/?file=104059#file104059line776>
> >
> >     Bo, I'm a little leery about converting the List and ArrayList to 
> > LinkedList and ConcurrentLinkedList.  I believe that linked list's will use 
> > more memory than the array list due to the double links (forward and 
> > backward).  Also, is ConcurrentLinkedList supposted to outperform a 
> > synchronized ArrayList?  I haven't seen much on that.
> >     
> >     The concurrenthashmap changes look good.
> 
> Bo Wang wrote:
>     Avery, thanks for the comments. I just measured the sizes of these 
> classes and below are an estimation. 
>     
>     java.util.ArrayList: 149 bytes
>     java.util.LinkedList: 101 bytes
>     java.util.concurrent.ConcurrentLinkedQueue: 118 bytes
>     
>     The tool I was using is a program from the link below.
>     http://www.javapractices.com/topic/TopicAction.do?Id=83
>     
>     In terms of performance, here is a benchmark.
>     
> http://www.javacodegeeks.com/2010/09/java-best-practices-queue-battle-and.html
>     
>     In its test #1 (adding element), ConcurrentLinkedQueue performed slightly 
> better than LinkedList. In test #3 (iterator), LinkedList outperformed 
> ConcurrentLinkedQueue. I think the most time consuming part is add, while 
> iteration is also heavily used but no concurrent accesses. 
>     
>
> 
> Avery Ching wrote:
>     Thanks for the response Bo.
>     
>     Those numbers are for the empty data structures I'm assuming.  I was 
> referring to the incremental cost of adding elements (messages) to the data 
> structures.  The performance isn't a a concern to me (unless we call size() 
> somewhere).

By the incremental cost, I mean the memory cost, sorry.


- Avery


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On 2012-04-24 06:11:38, Bo Wang wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> https://reviews.apache.org/r/4852/
> -----------------------------------------------------------
> 
> (Updated 2012-04-24 06:11:38)
> 
> 
> Review request for giraph.
> 
> 
> Summary
> -------
> 
> Use ConcurrentHashMap and ConcurrentLinkedQueue to allow concurrent assess to 
> message map. The concurrencyLevel of ConcurrentHashMap uses the default 
> value. There may be some performance gain by tuning this value.
> 
> 
> This addresses bug GIRAPH-185.
>     https://issues.apache.org/jira/browse/GIRAPH-185
> 
> 
> Diffs
> -----
> 
>   
> http://svn.apache.org/repos/asf/incubator/giraph/trunk/src/main/java/org/apache/giraph/comm/BasicRPCCommunications.java
>  1328747 
> 
> Diff: https://reviews.apache.org/r/4852/diff
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> Bo
> 
>

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