Re: [GridSim-developers] [GridSim-users] Crashed simulation with thousands of threads

[Agustín C. H. <ag...@ds...>]

Dear Shuo Yang,

The problem u r facing is quite difficult, and I think that the best way 
of tackling it is by tuning ur code. This is, make sure u don't waste 
memory unnecessarily. So, for example, every time that  some  object is 
not needed any more, delete it (set it to null so that the garbage 
collector releases the memory). 

Also, u can scale ur experiments, so that they become smaller.

Hope this helps,

Agustin

Shuo Yang escribió:
> Dear GridSim team,
>
> I'm Shuo Yang, a PhD student at University of Manchester, UK. I'm doing
> my research project with simulations based on GridSim. However I
> encountered scalability issues in the simulation where there are around
> 4000 threads (entities) with Java exception 
>
> 'java.lang.OutOfMemoryError: Java heap space'
>
> The simulation ran for ~48 hours with increasing memory usage and ended
> up with the OutOfMemoryError exceptions. Please could you help more with
> tuning? Here's more info:
>
> $ uname -a
> Linux nimue.rcs.manchester.ac.uk 2.6.18-1.2798.fc6 #1 SMP Mon Oct 16
> 14:54:20 EDT 2006 i686 i686 i386 GNU/Linux
>
> $ java -version
> java version "1.6.0_06"
> Java(TM) SE Runtime Environment (build 1.6.0_06-b02)
> Java HotSpot(TM) Server VM (build 10.0-b22, mixed mode)
>
>
> $ ps aux | grep java
>
> yangs    12579  109 43.7 2915672 1473316 ?     Sl   03:10 1011:15 java
> -Xss128k -Xms1024m -Xmx1024m -cp gridsim-lib/gridsim.jar:.
> topology/HierarchySimulation true
>
>
> $ free -mt
>              total       used       free     shared    buffers
> cached
> Mem:          3290       2055       1235          0         83
> 363
> -/+ buffers/cache:       1608       1682
> Swap:         8001          0       8001
> Total:       11291       2055       9236
>
>
> $ top
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  SWAP CODE
> DATA COMMAND 
> 12579 yangs     17   0 2847m 1.4g 5624 S  100 43.7   1057:02 1.4g   40
> 2.8g java 
>
>
>
>
> Many thanks,
>
> Shuo 'Alex' Yang.
> School of Computer Science
> University of Manchester
>
>
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-- 
===============================================
Agustin Caminero
Research Assistant.
Computing Systems Department.
Albacete Research Institute of Informatics (I3A).
The University of Castilla La Mancha.
Campus Universitario s/n, 02071, Albacete. Spain.
Phone: +34 967 599 200 Ext. 2693. Fax: +34 967 599 343
http://www.i3a.uclm.es/
===============================================