SAP Parameter vmcj/vm_auto_restart - Automatic VM restart


Short text
Automatic VM restart

Parameter description
This parameter specifies whether a VM is to be stopped automatically.This can be useful to temporarily correct errors (such as memory leaks).The VM is restarted either once a set time limit has been exceeded or ifthe "old generation" occupation of the Java heap has exceeded a setlimit value.
Furthermore, you can configure with the parameter whether VMs that haveto contribute to a shared garbage collection (SGC) and are currently inthe pool have to be stopped. This parameter only takes effect if VMcloning is active (see parameter vmcj/cloning ).With large data sets the SGS takes longer. This is why stopping andrenewing cloning of a VM can improve performance in such situations.
However, you should only set the parameter if SAP recommends that you doso.

Work area
vmcj/vm_auto_restart = <(><<)>Grund>* | <(><<)>Grund> , <(><<)>Grund>*<(><<)>Grund> = [<(><<)>Zeitwert>] | [<(><<)>OldGen-Limit>] |[BEFORE_SGC] <(><<)>Zeitwert> = TIME=<(><<)>Zahl> [ H|M] <(>
<<)>OldGen-Limit> = OLD_GEN=<(><<)>Zahl>
You can specify the time value with or without a time unit. If you donot specify a time unit, seconds is used as the unit. Otherwise M can bespecified for minute or H for hour. There can be spaces between thevalue and the unit. The value 0 means that the VM should not berestarted on the basis of a time interval.
The OldGen limit is a percentage between 0 and 100 %.
OLD_GEN=95 -> Stop VM if more than 95% of the old generation is reserved
TIME=1H -> Stop VM if the VM is older than one hour
TIME=1H, OLD_GEN=90 -> Stop VM if the VM is older than one hour or ifmore than 90% of the old generation is reserved.
BEFORE_SGC -> Stop VM if the VM is in the pool, has to contribute to anSGC, and VM cloning is active.
The value 0% means that no VM is to be stopped based on reservation ofthe old generation.

Default value
Empty (no VM is automatically stopped)

Who is allowed
Customer with SAP support

Limitation for os

Limitation for db

Other parameter

Character string