Recently in Java – dev_serverx log file,we have seen multiple warning occurred as below –
J :  01:32:31 ***Warning: Code cache is full: Try increasing the code cache size using -XX:ReservedCodeCacheSize=…
J :  01:32:31 ***Warning: JIT stopped
J :  01:32:31 ***Warning: JIT restarted
There is an Standard SAP note which is describing this situation & providing the multiple solutions –
2579836 – AS Java system has performance problem – FCAException – Best practices and tuning recommendations
Point No. 4 – Increase the code cache size to 1024 MB.
As per SAP, we need to increase the parameter ReservedCodeCacheSize to 1024M value but currently this parameter is not set in our system. it’s using the default 250M (Code Cache Size) value.
For Verification of the present code cache size & usage follow the below note –
2632653 – How to check present Code cache usage on SAP JVM
In my case, I am not able see Code Cache size via graphical tool then we use jvmmon tool to dump the code cache as below –
The SAP JVM Monitoring Tool jvmmon can be used to obtain the present value of the code cache. Steps are:
> Start the jvmmon
> Connect to the PID
> dump jit info
The output is written into the std_server file in the work directory. Click here for more information on the SAP JVM Monitoring Tool: jvmmon.
we did set this parameter in config tool as defined in SAP note & restart the whole cluster including DB & observe the performance of the system. it’s since more then a week, we didn’t see this Warning any more in dev_serverX log file.
Will wait for another month & see if this situation reoccurs & will update with next resolution.