We are facing problem in SAP. The performance of the system is very low and all the dialog workprocess are entering 'PRIV' mode in 'ONHOLD' state.
Can you please say me what are the possible reasons for process to enter 'PRIV' mode?
Thanks in advance
These parameters are basically related to performence problem.
Just check the extended memory uses in ST02. In any time it should not be more then 90%. Whenever a memory uses is high and program are not able to execute in a given dialog Nondialog heap area & extended memory area, workprocess gone into PRIV mode
I think you should increase some parameter value
A work process enters PRIV mode when either a) extended memory is exhausted or b) the process has used the amount of memory specified in ztta/roll_extension.
You can check this in SM50 by doubleclicking on the process in PRIV mode to determine if it is because you are using too much total memory (~2GB is too much), or because something else used up all your extended memory and this is just a by product of running out of extended memory.
If all the work processes are going in the PRIV mode, it is very possible to be Kernel bug which you can check with SAP.
Understanding the HEAP memory better, If a dialog work process has used up the roll area assigned to it and the extended memory, private memory is assigned to the work process. The work process goes into PRIV mode (private).
In the parameter settings, ensure that not too many dialog work processes are simultaneously in the PRIV mode, since this lowers system performance.
The other Work Process types (background, update, enqueue and spool work processes) are assigned heap memory after the roll area is used up. Allocating Extended Memory is not useful since no context change occurs for these processes.
Other processes cannot use private (heap) memory. After releasing the assigned memory, the operating system still considers the (virtual) memory as being occupied by the allocating process. These characteristics of heap memory require that:
1. The work process can be run in PRIV mode (private) when the local memory is assigned. This means that the work process is reserved for processing the current user context until the context releases the work process again when the request has ended.
2. The work process, if it has used a lot of private memory, is restarted when the user context is terminated and the local memory is returned. The restart makes the local memory available again for other processes. A restart occurs if a work process uses more local memory than is defined in the parameter abap/heaplimit. The mechanism is displayed again there.
Automatic Termination of PRIV Mode Processes:
If too many dialog work processes run in the PRIV mode in an SAP application server, performance problems arise. The normal processing of user inquiries is slowed down by the PRIV mode work processes.
The SAP System offers a mechanism that lets you terminate non-active dialog processes in the PRIV mode. This mechanism helps reduce performance problems.
The mechanism works as follows:
In the PRIV mode, a maximum number (n) of dialog work processes can run without any time restrictions.
To determine this number n, set the value of the profile parameter rdisp/wppriv_max_no. If a value is not entered, the SAP System determines this number using the following formula:
the number (n) is set to the greater of the 2 following values:
Number of dialog work processes minus 5
If more than (n) dialog work processes are active and the time span set in parameter rdisp/max_priv_time (default 600 seconds) has elapsed, the transaction for that PRIV process, which has spent the longest possible time in PRIV mode, is reset.
Hope this information helps in sorting out the issue.
(*Award point if useful.)
As most/all of your WP's are in PRIV it is not that a couple of people are using more than their allowed allocation of extended but that extended memory has become exhausted. This you can see easily in ST02 and the history in ST02 should show how often your extended memory is hitting 100%. This must be resolved, it is a poor and potentially dangerous situation for your system.
This quick answer is to increase em/initial_size_MB. If you need a more detail investigation, let me know.
Edited by: Graham Newport on Mar 24, 2008 11:58 PM