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Keyword: BASIS
Title : SAP Netweaver 2004s - Components of Monitoring - Global Workload Monitor

SAP Workload Analysis: Average Database Time per Dialog Step (ms)

A large portion of the "dispatched" time in a dialog is due to the reading and changing of data in the database, This field stores the time required for processing logical database calls (calls to the SAP database interface).

Various factors influence the logical database access time. Read requests can be responded to either by the database buffer or the fast local SAP buffer. The buffer efficiency, the number of the required accesses, and a high number of DB change accesses influence the total access time.

The database access time is measured in the database interface in the application server. This is why this also includes part of the application server CPU time and the network transfer time.

SAP Workload Analysis: Ø Time for DB Proc. Calls per Transact. (ms)

Average time per transaction step for database accesses using database procedures

As well as SQL statements, database procedure calls can be sent to the database interface. In a database procedure, part of the processing logic can be performed by the database itself.

SAP Workload Analysis: Average Roll In Time per Dialog Step (ms)


Time used during a dialog step for rolling in the user context from the roll area into the local process memory.


During roll-in and roll-out operations, user-specific data from the roll buffer of shared memory or the roll file is loaded into the work process area and exported to the roll buffer or roll file.

SAP Workload Analysis: Number of Sequential Reads

Definition

Database calls of the type "sequential reads" are initiated by ABAP commands such as SELECT * FROM. If possible, the data is read from the local SAP buffer, otherwise from the database itself.

SAP Workload Analysis: Average Usage of All Memory Types (KB)

The average memory usage is calculated by dividing the total memory usage by the number of associated dialog steps.

The total memory usage is made up of the components roll memory, extended memory and heap memory. Work processes use memory in the following order:

Roll Memory to the limit set by ztta/roll_first

Extended memory to limit set by ztta/roll_extension or until there is no more space available in extended memory.

Roll Memory: rest of the space in the roll area until ztta/roll_area.

Heap Memory until abap/heap_area_dia is reached or all space in heap memory is used.

For non-dialog work processes, there used to be an allocation order.

SAP Workload Analysis: Task Type Name


The SAP System includes several task types differentiated by the tasks assigned to the corresponding application process. The task type is used as an identifying part of the statistics record.

The task types are:

AUTOABAP: Automatically processed reports such as used for certain monitoring tools.

BATCH INPUT: Transaction step in batch input session. This transaction step is processed in the dialog work process. Update dialogs triggered during batch input sessions are processed in parallel (fall under the category task type = "UPDATE").

BACKGROUND: Transaction step processed by a background work process.

BUFFER SYNC is a synchronization of the local table buffers triggered by the SAP System. This transaction step is executed regularly at short intervals. This interval is set by the profile parameter "rdisp/bufreftime".

DIALOG is an online transaction step usually initiated by the user on a screen, such as editor dialogs, manual postings, and so on.

RFC: Remote Function Calls in the R/3 System are processed by the dialog work process.

CPIC: Other communication through the CPIC interface (in the dialog work process).

SPOOL: Transaction step processed by spool work process

UPDATE is a transaction step processed by the SAP update process. Updates are automatically triggered by the dispatcher process on servers with active update processes. Update processes are normally installed on the database server.

ALE: IDOC processing in a dialog work process.

SAP Workload Analysis: Number of Steps


Number of transaction steps in the SAP System.


In a dialog task, one transaction step corresponds to a screen change; a request executed by the R/3 System for a user.

A background job can consist of one or more transaction steps, if several job steps are processed.

An update request triggered by a call from the dialog or the background corresponds to one transaction step, even if several updates are processed.

Several print requests are usually processed during one spool step.


The R/3 kernel generates a statistical entry for each transaction step; you can analyze the entries using the business transaction analysis.

SAP Workload Analysis: Average Response Time per Dialog Step (ms)

Response time per dialog step

The response time of a dialog step is the time required for requesting the dialog from the dispatcher work process to the processing of the dialog through the ending of the dialog in the dispatcher and the transfer of the data to the presentation server.

This also includes the time used for "Roundtrips" to transfer data from the SAP R/3 frontend to the application server and back. This time is recorded as roll wait time on the application server, while it is displayed as GUI time on the frontend. For inefficient networks, such as WAN connections, this time can contribute significantly to the response time, although it uses no resources on the application server, as the context is rolled out and the work process is released.

The response time is usually split into wait time and "dispatched" time. The SAP response time is made up of the following components:

Response time = wait time + "dispatched" time

"Dispatched" time

= Generation times during the runtime

+ Load times for programs, screens, and GUI interfaces

+ Roll times for rolling in work data

+ ABAP processing times

+ Database time

+ Enqueue time for logical SAP locks

+ Roll wait time (not including task types RFC/CPIC/ALE).

The CPU time is not an additive component of the response time, but rather the sum of the CPU time used by the individual components. The CPU time is an independent additional piece of response time information.

SAP Workload Analysis: Average CPU Time per Dialog Step (ms)

The CPU of the application server is used during a dialog step for processing. This includes, for example, loading and generating objects or database queries as well as processing ABAP commands.

The operating system determines the CPU time. At the end of a transaction step, the SAP R/3 work process queries the operating system for CPU time used. The CPU time is not an additive part of the response time (unlike wait, roll in, load, and database times).

SAP Workload Analysis: Average Wait Time per Dialog Step(ms)


Average wait time per Dialog step

Under normal conditions, the dispatcher should immediately dispatch a dialog step to the work process, whereby the average wait time in the dispatcher process is a few milliseconds.

If there is a high load on the application server or the entire system, wait situations occur in the dispatcher queue. Factors influencing when wait times occur are the number of work processes on the application server and the CPU load (ST06 -> CPU: Load average).

SAP Workload Analysis: Average Roll Wait Time (ms)

During processing of some dialog steps, the user context may be rolled out, for example, during RFCs when the client is waiting for a response from the server. This wait in the roll area until the dialog step can continue is called the "roll wait time".

SAP Workload Analysis: Average Load and Generation Time (ms)

The load and generation time is the time required to load objects such as source code, GUI interfaces, and screen information from the database and generate these objects, if required.


For task type RFC, the roll wait time is not included in the response time.

SAP Workload Analysis: Average CPIC / RFC Time per Dialog Step (ms)

Average CPIC/RFC time per dialog step

For task types RFC/CPIC/ALE, this is only the time used in the CPIC/RFC interface.

For all other task types, the RFC processing time is added as well.

SAP Workload Analysis: Data Requested from Database (KB)

Amount (KB) of database data transferred


A number of interfaces are used to provide data for various uses by the SAP application. The requested data is differentiated according to the following interfaces and data types:


Screen sources

Screen load

ABAP sources

ABAP load

CUA sources

CUA load

Nametab interface

CPIC interface

DDIC interface

DSQL interface (user data from the database)

"Roundtrips" is used to display the number of communication steps.

SAP Workload Analysis: Number of Direct Reads

Number of logical database calls of type "direct read", such as "SELECT SINGLE ..." statements in ABAP. These calls may be able to be satisfied from the local (partial) SAP buffer. Otherwise, the system must access the database.