Configuration Parameters 

Use

The following parameters are used to set the basic properties of the VM Container:

●      Activation of the VM Container: vmcj/enable

●      Maximum and minimum number of VMs: rdisp/max_jvm, rdisp/min_jvm

●      Activation/deactivation of VM cloning: vmcj/cloning

●      Maximum number of VMC subrecords in each statistical main record: stat/vmcrec

You can also fin information about important parameters for the JIT Compiler.

Integration

For more information about other parameters, see Memory Parameters.

Features

The profile parameters are described below. You can change the values by changing the profile and restarting the VM Container (see VM Overview).

SAP recommends that you do not change the standard settings. They are set for normal operation of the VM Container.

vmcj/enable 

Specifies if the VM Container is activated. Possible values:

ON: Activates the VMC.

OFF: Deactivates the VMC.

ENABLE: Initializes the VMC, but does not activate it. You can then activate the VMC dynamically in the VM Overview (transaction SM52).

Default value: OFF.

rdisp/max_jvm

Determines the maximum number of Java VMs that were created for HTTP (Web) and RFC/RMI (REM) processing. If needed, new VMs can be created up to this maximum value.

Possible values:

WEB=[DEFAULT | 0-n ], REM=[DEFAULT | 0-m]

The effect of the special value DEFAULT is to make the maximum number of VMs of each type is dependent on the number of configured work processes (is double the number of work processes).

Default value: WEB=DEFAULT, REM=DEFAULT

rdisp/min_jvm

Determines the minimum number of Java VMs created for HTTP (Web) and RFC/RMI (REM) processing.

Possible values:

WEB=[0-n ], REM=[0-m]

Default value: WEB=1, REM=1

vmcj/cloning

Activates the VM cloning (provided all prerequisites are fulfilled). The prerequisite for VM cloning is the implementation of extended memory mapping (see parameter em2/implementation under Memory Parameters).

ON: Activates the VM cloning.

OFF: Deactivates the VM cloning.

Possible values: [ON | OFF]

Default value: ON

stat/vmcrec

This parameter affects the VMC statistics within the SAP statistics. It specifies how many VMC sub-records can be contained within one statistic record.

Possible values: whole numbers

Default value: 10

rdisp/sessionTableCheck

With this parameter you can activate runtime monitoring of the VMC session table. You can also start the check in transaction SM52 (see Functions for the VM Container (Menu VMC).

The check is then triggered by the task handler at regular intervals. The interval is specified in the value of the parameter rdisp/autothtime and the defautl value is 60 seconds.

ON: Activates runtime monitoring.

OFF: Deactivates the runtime monitoring.

Possible values: [ON | OFF]

Default value: ON

Parameters for the JIT Compiler

You can set the following parameters in the profile to control the behavior of the JIT Compiler.

vmcj/option/jit/compile

This parameter control how many methods are translated by the JIT Compiler. The default setting policy means that the system decides when a method is best translated into machine code. This is the case if the method is called frequently.

You can also deactivate the JIT Compiler completely with this parameter (value none). Then all Java byte code is interpreted and not translated. This reduces system performance and is only sensible to use if you suspect there is an error in the JIT Compiler.

The setting all means that each method is compiled before the first call. This setting is used for testing. It does not optimize performance, and increases the memory requirement of the JIT Compilers.

We recommend you leave the default setting.

Possible values: [none | policy | all]