SAP JVM Switch Guide with Screenshot

[nicholas_chang]

Starting october 1st 2012, SAP JVM 4 will be the only  supported option for SAP Web Application Server 6.40 and SAP NW 7.0 system. Therefore, we are advisable to perform the switch from 3rd party vendor JVM to SAP JVM 4.

I believe many customers out there still reluctant to carry on the switch, due to unknown impact after the switch. Hereby, content of this blog will show how easy  the switch is and 99% of the tasks are automated.

Reference Notes:

Note 1665953 - SAP JVM Switch Tool Composite Note

Note 1442124 - How to download a SAP JVM patch from the SMP

Note 1367498 - SAP JVM installation prerequisites

Note 1603093 - SAP JVM 4.1 parameters NetWeaver 2004 and 7.0

Note 1649026 - SAP JVM Switch tool: Configuring Replication using sapcpe

(Platform is Linux X86_64)

Step 1 :

Download the latest SAP JVM Switch tool from:

SAP Technology Components -> SAP JVM 4.1 -> SAP JVM SWITCH TOOL 1.0 -> Support Package Patches -> <OS version> -> and download the latest level

Currrent level - SAPJVMSWITCH00P_8-20008217.SAR

and SAP JVM 4 from:

SAP Technology Components -> SAP JVM 4.1-> Support Package Patches -> <OS version> -> and download the latest level

Current level - SAPJVM4_20-10009718.SAR

Download the Guide from:

https://websmp102.sap-ag.de/instguides -> SAP JVM Switch Tool -><OS version>

Step 2 :

Extract SAPJVMSWITCH00P_8-20008217.SAR into a temporary folder. As SIDadm, check the JAVA_HOME env.

eg: JAVA_HOME=/opt/IBMJava2-amd64-142

Step 3 :

Launch sapinst from the extracted folder as ROOT.

Step 4:

i) enter your profile directory

ii) point to the location where you've download SAPJVM4_20-10009718.SAR

iii) enter the path to JCE_SAPCRYTO

iv)

Verify with Note 1603093 - SAP JVM 4.1 parameters NetWeaver 2004 and 7.0 and you can insert all the necessary JVM parameter here.

eg: add -XX:+UseTLAB for Server Node according to the note. Besides that, you can change and adjust the heap memory here for Server and Dispatcher Node.

v) SAPINST start running and performing the task:

vi) Below message appears after 3-5mins. Restart you SAP instance to complete the JVM switch.

vii) Check JAVA_HOME after instance restarted and it should returns as below:

JAVA_HOME=/usr/sap/SID/SYS/exe/jvm/linuxx86_64/sapjvm_4.1.020/sapjvm_4

viii) Open java url:: http://host:5XX00 -> system info and you'll see version is changed to 4.1.020 for both dispatcher and server.

FYI, the whole process and downtime is less than 10 mins. Everything is so easy and automated, what you need to do is just restarting SAP instance for the switch to take effect. Besides that, if you hit any unexpected error (very rare case) you can still revert back to your previous partner vendor JVM by following the instruction in file switchJDK.txt, located in sapinst_instdir.

Please take note you need to perform additional preparation steps for Heterogeneous Systems. Please refer to SAP JVM Switch guide for detailed steps.