J V M H E A P N E W A R E A S I Z E
The Generational Garbage Collector introduced in Java 5.0 is efficient to Portal application JVM memory management, and it is set as default by installation with the
The
How To Set: In the WebSphere Administrative Console: Servers Application Servers
WebSphere Portal Server Infrastructure: Java and Process ManagementProcess Definition Java Virtual Machine
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| New Area Size |
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A D D I T I O N A L S U N J V M A R G U M E N T S
On the Solaris platform, we use the following Java HotSpot parameters to achieve optimum performance.
Table 1: Additional Sun JVM Settings
Parameter | Value | Additional Information |
| Offers higher throughput than the "client" mode. | |
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768m |
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| Use concurrent |
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| generation. The application is paused for short periods |
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| during the collection; we found this collector works best |
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| in Portal. |
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| 6 |
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| By default concurrent low pause collector uses the |
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| default, single threaded young generation copying |
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| collector. Set this parameter to use parallel young |
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| generation collector for new area. |
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| 5 | Reduces the number of garbage threads. On the Chip |
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| multithreading processor based system, we set the |
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| threads no higher than one quarter of the hardware |
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| threads. We also distribute the threads for 6 JVMs. Our |
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| system has 128 virtual processors, we set a total of |
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| (128/4)=32 GC threads across all the JVMs. So 5 or 6 |
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| GC threads per JVM. |
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| Print more details at garbage collection. This does not |
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| improve performance, but it provides additional |
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| information related to garbage collection activity, which |
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| is useful in tuning garbage collection. |
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| Print timestamps at garbage collection. See above. |
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W E BS P HE R E P O R T AL V 6 . 1 T U N I N G G U I D E
