VM Container Functions (Menu VMC)

Display Status

Choose  VMC  Display Status  to display the value of the VMC status variables. This displays information about the VMC, which you can also see in the header area of the initial screen (see VM Overview: General Information). You can also see information about the SAP kernel, and about the activation status of startup debugging (see below).

Activate

Choose  VMC  Activate  to activate the VM Container to enable interprocess communication with the ABAP processor. If necessary, the system starts non-instantiated VMs in accordance with the server configuration.

Deactivate

Choose  VMC  Deactivate  to deactivate the VM Container so that inter-process communication with the ABAP processor is no longer possible. VMs already instantiated will continue to run.

Reset

Choose  VMC  Reset  to initialize the VM Container again.

Check VM Pool

Choose  VMC  Check VM Pool , to examine the VM pool. The check specifies whether the current number of VMs lies within the defined area [minimum number of VMs, maximum number of VMs]. If it does not, VMs are either started or also stopped.

Memory

Choose  VMC  Memory  Check  to check whether VM memory areas in the shared memory are still occupied, even though the associated VM is no longer running. If there are no memory areas still occupied, you will get the message Memory Areas OK. If memory areas are still occupied, you will get the message Unreferenced memory areas found. Choose  VMC  Memory  Cleanup . The memory areas still there are then deleted.

Trigger Shared Garbage Collection

You can trigger a shared garbage collection by choosing  VMC  Memory  Shared GC . You can reset the counter for the shared GCs by choosing  VMC  Memory  Delete GC Counter .

More information: How the Shared Garbage Collector Works.

Sessions

Choose  VMC  Sessions  Display  to see in the VMC Sessions view the number and attributes of the user sessions currently running. The maximum number of sessions configured is also given in the header line.

Choose  VMC  Sessions  Check  to start the check in the VMC session table. In this table all the valid Java sessions of the Virtual Machine Container (VMC) are managed. It consists of a kernel and a Java part. The check examines the consistency of both parts. You can run also this check periodically by setting the parameter rdisp/sessionTableCheck (see Configuration Parameters).

Files

Choose  VMC  Files  to display in the VMC Files view the number and attributes of the files currently opened by the VMC. The maximum number of files configured is also given in the header line.

Error Text

Choose  VMC  Error Info  to get details of the last error that occurred (see VM Overview: General Information).

VM Reservation

Choose  VMC  VM Reservation  to temporarily reserve a VM of type RFC, for example, to set specific trace flags in this VM.You can reserve the VM using the submenu Activate. The VM will then be flagged in the Table of VMs with the reserved status and with your user name. Choose  VMC  VM Reservation  Deactivate  to cancel the reservation.

Debugging

You can make the following configuration settings for the debugging.

• Startup debugging enables debugging when the VM is initialized.

• The debug proxy is used for accelerating Java debugging via WAN.

Startup Debugging

This function sets up the connection to a debugger when a VM is initialized, which is at the earliest possible time. A confirmation popup appears.

Switch on

Choose  VMC  Startup Debugging  Activate , so that the system waits for the connection to a debugger for each instantiation of the selected VM type. On the VMC Status screen (see above) the status displayed is Startup debugging is active.

Switch off

Choose  VMC  Startup Debugging  Deactivate , so that the system does not wait for a connection to a debugger for each VM instantiation. On the above VMC Status screen the status displayed is Startup debugging is not active.

Debug Proxy

The debug proxy is a software component that speeds up Java debugging across the WAN. It consists of a back end in the VM container (AS ABAP) and a front end integrated in the SAP NetWeaver Developer Studio.

Start Debug Proxy

If you want to use the debug proxy, you have to start the back end. In the VM Overview (SM52) choose  VMC  Debugging  Debug Proxy  Activate .

Check Status

You can check whether the debug proxy is active. In the VM overview (SM52) choose (SM52)  VMC  Display Status .

Configure Port

The back end of the debug proxy communicates with the front end through a configurable port. The standard setting is 55555, and you can change the port in profile parameter vmcj/debug_proxy/port in the VM container. The parameter can also be changed dynamically in transaction RZ11 when the VM container is running.

As well as this port number, the communication between the VM container (on which the Java application to be debugged is running) and the SAP NetWeaver Developer Studio also requires the debug port of the Java VM. We can see this in the VM overview (SM52) in column Debug Port, as soon as the Java code is debugged. At the same time you are also informed of the port in a popup or in the status bar. You then need to set this manually in the SAP NetWeaver Developer Studio.

Stop Debug Proxy

To stop the debug proxy, choose  VMC  Debugging  Debug Proxy  Deactivate .

Shared Lock Statistics

The shared lock statistics produces the following information about Shared Locks:

• Lock name: The name of the lock provides information about the application that has set the lock.

• Locks: Number of lock operations for a shared lock

• Wait time: Total wait time for a shared lock in microseconds

• Lock time: Total duration of lock (time in critical section) of a shared lock in microseconds

• Minimal and maximal time in the critical section (in microseconds)

• Number of lock operations in a specific time interval: In these columns you can see how many lock operations have lasted less than one microsecond, between one and two microseconds and so on.

Choose  Shared Lock Statistics  Activate  to activate the recording of the statistics for the shared lock operations. If the statistics are active, you can display them with  Shared Lock Statistics  Activate .

You can close the recording ( Deactivate) or reset the collected data ( Reset).

Exit

Choose  VMC  Exit  to leave the transaction.