With SAP JVM 4.1, customers can get as long support for their JDK as they get for the remaining SAP NetWeaver 2004 and SAP NetWeaver 7.0 based software from SAP. SAP JVM 4.1 is supported directly by SAP.
Solution
In the following we describe two sets of JVM parameters: One set for the server nodes and one for dispatcher nodes of an SAP NetWeaver Application Server Java.
The server node parameter set distinguishes parameters for 64 bit, 32 bit and parameters independent thereof.
The parameter sets described below target a typical SAP NetWeaver Application Server Java installation. Individual modifications might be applied, e.g. for the Java heap size.
1. General remark on the Maximum Heap Size
The maximum heap size is usually specified in the field "Max heap size (in MB)" in the Configtool. Therefore it is not needed to set it explicitly using the '-Xmx' option mentioned in following sections. If specified by '-Xmx', it will overrule any other setting. There is no preferred way to specify the maximum heap size. Both will lead to the same result.
2. Server Nodes
For server nodes you will need the architecture independent parameters plus either the 32 bit parameter set (for Windows on x86 or Linux on x86) or the 64 bit parameter set (for all other platforms).
a) Architecture independent parameters
The following parameters apply for 32 and 64 bit platforms.
-XX:+UseConcMarkSweepGC
Remark: The Concurrent Mark & Sweep Garbage Collector is the recommended GC for all platforms
-XX:+DisableExplicitGC
-XX:TargetSurvivorRatio=90
-XX:SurvivorRatio=4
-XX:+UseTLAB
Remark: Mentioned only for completeness. Can be omitted, since it is set by default in the SAP JVM
-XX:+PrintGCDetails
-XX:+PrintGCTimeStamps
-XX:+HandlePromotionFailure
Remark: Mentioned only for completeness. Can be omitted, since it is set by default in the SAP JVM
-verbose:gc
-XX:SoftRefLRUPolicyMSPerMB=1
-XX:HeapDumpPath=OOM.hprof
-XX:+HeapDumpOnOutOfMemoryError
-Djco.jarm=1
-Djava.awt.headless=true
-Djava.security.policy=./java.policy
-Djava.security.egd=file:/dev/urandom
-Dsun.io.useCanonCaches=false
-Dorg.omg.CORBA.ORBClass=com.sap.engine.system.ORBProxy
-Dorg.omg.CORBA.ORBSingletonClass=com.sap.engine.system.ORBSingletonProxy
-Dorg.omg.PortableInterceptor.ORBInitializerClass.com.sap.engine.services.ts.jts.ots.PortableInterceptor. JTSInitializer
Remark: There is no "=" missing. A dot is used as separator instead. Please write all in one line without separating spaces. The parameter name is just broken down for readability.
-Djavax.rmi.CORBA.PortableRemoteObjectClass=com.sap.engine.system.PortableRemoteObjectProxy
-Dcom.sap.jvm.scenario=j2ee
Remark: This parameter will enable the GC history and to always look for the .hotspot_compiler file in JAVA_HOME instead of the current working directory.
b) Additional parameters for 32 bit platforms
The followng additional parameters apply for Windows/x86 and Linux/x86.
-Xms1024m
-Xmx1024m
-XX:MaxNewSize=300m
-XX:NewSize=300m
-XX:MaxPermSize=256m
-XX:PermSize=256m
-Xss1m
c) Additional parameters for 64 bit platforms
-Xms2048m
Remark: If larger values were already used prior to the JDK switch, they should be retained
-Xmx2048m
Remark: If larger values were already used prior to the JDK switch, they should be retained
-XX:MaxNewSize=600m
Remark: If you increase the total heap size (Xmx) you can increase the MaxNewSize in a proportional manner if necessary
-XX:NewSize=600m
Remark: If you increase the total heap size (Xmx) you can increase the NewSize in a proportional manner if necessary
-XX:MaxPermSize=512m
-XX:PermSize=512m
-Xss2m
3. Dispatcher Nodes
For the dispatcher nodes all platforms can use the same parameter settings described below. If the instance contains more than three server nodes we recommend to add 50MB of heap for each additional server node.
a) Architecture independent parameters
-Xms256m
-Xmx256m
-XX:+UseConcMarkSweepGC
-verbose:gc
-Djava.security.policy=./java.policy
-Dcom.sap.jvm.scenario=j2ee
Remark: This parameter will enable the GC history and to always look for the .hotspot_compiler file in JAVA_HOME instead of the current working directory.
b) Additional parameters for 32 bit platforms
-Xss1m
c) Additional parameters for 64 bit platforms
-Xss2m
For more information
please review the SAP Note -
