Workload Overview

Definition

The workload overview outputs data about the workload that is written by the SAP kernel and displayed using the workload monitor (transaction ST03N). The workload overview provides system administrators with various detailed information about the most important workload data, such as CPU time, the number of database changes, response times, and so on.

In SAP Basis 4.6C, the workload monitor was extended so that it now also includes GUI times, Frontend network times and the RFC time.

Structure

You can display the workload overview for all task types (Dialog, Background, RFC, ALE and Update) or for one particular task type. The system displays the following data:

Information	Explanation
Average CPU Time	Average time that a workprocess uses the CPU; during a dialog step, the CPU of the application server is used for processing (loading, generating, processing database requests, ABAP processing, and so on). The CPU time is determined by the operating system. At the end of a transaction step, the SAP work process queries the CPU time from the operating system. The CPU time is therefore not an additive component of the response time, unlike wait time, roll in time, load time and database time.
Average Response Time	Average time between the time at which a dialog process sends a request to a dispatcher work process, and the time at which the dialog is completed and the data is transferred to the presentation layer. The response time does not include the time for transferring the data from the SAP frontend to the application server. For networks with bad performance, a more subjective response time can therefore emerge. The transfer time is included in the GUI time and the Frontend network time.
Average Wait Time	The average time an unprocessed dialog step waits in the dispatcher queue for a free work process. Under normal circumstances, the dispatcher work process should pass a dialog step immediately after receiving the request from the dialog step. In this situation, the average wait time should be only a few milliseconds. If the application server of the entire system is under a heavy load, this can lead to traffic jams in the dispatcher wait queue.
Average Load and Generation Time	Average time required to load and generate objects such as ABAP source code and screen information from the database.
DB Calls	Number of parsed accesses to the database
DB Access	Number of logical ABAP accesses to data in the database; these accesses are made through the SAP database interface and are parsed into individual database calls. The ratio of database calls to database accesses is important. If the access to information in a table is buffered in the SAP buffer, no database calls to the database server are required. The ratio of Calls/Accesses therefore gives an indication about the efficiency of the table buffering. A good ratio would be 1:10.
GUI Time	Response time between the dispatcher and the Gui during the roundtrips (roundtrips are communication steps between the SAP system and the frontend during a transaction step).
Roll Ins	Number of rolled in user contexts
Roll Outs	Number of rolled-out user contexts
Roll In Time	Processing time for the rolling in of user contexts
Roll Out Time	Processing time for the rolling out of user contexts
Roll Wait Time	Wait time in the roll area When synchronous RFCs are called, the work process performs a roll out and waits for the end of the RFC in the roll area. The RFC server programs can wait for other RFCs to be sent to them in the roll area.
Average Time per Logical Database Call	Average response time for all commands sent to the database system (in milliseconds). The time depends on the CPU capacity of the database server, the network, buffering, and on the input/output capabilities of the database server. The access times for buffered tables are far faster and are not considered here.

Background information

The response time is usually split into wait time plus execution time. The SAP response time is made up of the following components:

Response Time = Wait Time + Execution Time

where: Execution Time =

Generation time during the run

+ Load time for programs, screens and the graphical interface
+ Roll times for rolling in the work data
+ ABAP processing time
+ Database time
+ Enqueue time for logical SAP lock processes
+ CPIC/RFC time
+ Roll wait time (excluding Task types RFC/CPIC/ALE)

The CPU time is not an additive component of the response time, but the total of the individual components of the utilized CPU time. The CPU time is therefore an additional, independent piece of information about the response time.

Workload Monitor

Purpose

The workload monitor (transaction ST03N) is intended for use by EarlyWatch and GoingLive teams. The workload monitor was reworked as part of the EnjoySAP initiative, so that the Workload Overview is now simpler and more intuitive.

You use the workload monitor to analyze statistical data from the SAP kernel. When analyzing the performance of a system, you should normally start by analyzing the workload overview. For example, you can display the totals for all instances and the compare the performances of individual instances over specific periods of time. You can quickly determine the source of possible performance problems using the large number of analysis views and the determined data.

You can use the workload monitor to display the:

• Number of configured instances for each SAP R/3 System
• Number of users working on the different instances
• Distribution of response times
• Distribution of workload by transaction steps, transactions, packages, subapplications, and applications
• Transactions with the highest response time and database time
• Memory usage for each transaction or each user per dialog step
• Workload through RFC, listed by transactions, function modules and destinations
• Number and volume of spool requests
• Statistics about response time distributeion, with or without the GUI time
• Optional: Table accesses
• Workload and transactions used listed by users, payroll number, and client
• Workload generated by requests from external systems

For all of this data:

• You can display the data for a particular instance (not only the one to which your logged on) or optionally totalled for all instances.
• Depending on your user mode, you can choose the time period for which you want to display the data between day, week and month (or determine the length of time yourself using the
Last Minutes’ Load function).
• For most analysis views, you can display all or only certain task types.

Integration

The workload monitor completely replaces the old ST03 transaction.

Features

The workload monitor has an interface that is divided into two parts. Use the tree structures on the left of the screen to make the following settings:

• Select the
user mode
• Select the time period for which you want to display the workload
• Select various functions and analysis views (which data you want to display).

The system then displays the result on the right of the screen in a standardized ALV Grid Control. With it, you can :

• 
  
Adjust the Layout of the Data Output
• Find the information you want using sort and filter functions
• Save user-specific views
• Display statistics graphically

Operating the Workload Monitor

The workload monitor is a one-screen transaction that has as few additional menus as possible. This makes operation significantly easier and more intuitive.

Integration

The workload monitor transaction ST03N replaced the old ST03 transaction.

Features

Activities

The individual screen elements of the workload monitor mean the following:

User Mode

After starting the workload monitor, you should first choose a user mode. Through this, you gain access to precisely the functions and time periods that are relevant for the selected role.

Functions

In the Functions subscreen, choose a symbol by double clicking it:

Function	Meaning
Workload	Here you can define the instance and the time period that you want to define, in accordance with the user mode.
Detailed analysis	These functions read the workload directly from the statistics files of the individual instances.
Business transaction analysis	Here, you can perform a very precise analysis of individual transaction down to the level of individual steps.
Last minutes’ load	Here you can analyze the workload data that has not yet been written to the MONI performance database.
Load history and distribution Load history Instance Comparison Users per Instance	Here (unlike in the workload monitor), you cannot display the workload for a particular instance and a particular time period, instead you can compare the workload for instances or time periods. A comparison of the most important data allows you to directly compare the instances.
Collector & Perf. Database	Here you can determine, among other things, which values the statistics collector determines, and how often, and for how long they should be retained in the performance database.

Analysis Views

An analysis view displays a particular aspect of the workload. In the analysis views subscreen, choose the view that you want to analyze by double clicking it.

Only those Analysis Views are shown that:

• Are active in the selected user mode
• Exist for the data

Output Area

The output area uses an ALV Grid Control, with which you can greatly tailor the selected view to your requirements. For most load parameters, the workload monitor displays more data fields than are required for your analysis. You therefore have a considerable amount of help in the output area to obtain the data that is relevant for you:

• The data for most analysis views is grouped in tab pages by various topic areas
• To obtain an overview of which data fields exist for an analysis view, choose the All Data tab page.

• Using the
standard functions of the ALV Grid Control, you can:

• Show and hide columns
• Sort lines by the contents of a column
• Set and delete filters
• Perform summations
• Export tables in a file type of your choice
• Display tables as graphics
• Save sort orders, filters, and selected columns as your layout

Edit Views

Choose one of the following pushbuttons in the Edit Views screen area:

Pushbutton	Meaning
Save View	Saves the current view as your initial screen for the workload monitor (see also Saving User-Specific Views).
Previous View or Next View	Moves one view forward or backward in the view history
Full Screen: Show/Hide Tree	Shows or hides the Functions and Analysis Views sections in the left-hand part of the screen.