sap bw accelerator governance process

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© 2009 SAP AG 1

SAP BW Accelerator Governance

Process

Applies to:

SAP NetWeaver 2004s BI 7.0 Support Pack Stack 16 with BWA revision 7.00.53.00. For more information, visit the Governance, Risk, and Compliance homepage.

Summary

SAP BW Accelerator is an innovative solution for BI customers that enable them to deliver maximum speed and flexibility needed to leverage the SAP BW Investment. This is based on SAP’s search and classification engine on specially configured hardware. A competitive advantage can be created by following the Governance process for high availability of BWA.

Authors: Pradeep Banwar, Simone Kuderer

Company: Infosys Technologies Limited & Syngenta Crop Protection AG

Created on: 25 September 2009

Authors Bio

Pradeep Banwar

The author has been associated with Infosys Technologies Limited for 2 years and has been in a Sr Consultant role in the Process and Domain consulting Stream. He has been involved in a BW upgrade and BWA Implementation Project and currently assisting the BW Design Authority for a renowned Client in this domain.

Simone Kuderer

Simone worked for 6 years as a SAP BW Senior Consultant in SAP Partner Consultancies before becoming the Lead of BW Design Authority in Syngenta Crop Protection AG 3 years ago. The SAP BW system designed as Enterprise Data Warehouse (EDWH), it’s a global system with global, regional and local data with approx. 5.5 TB of data and 4000 users worldwide.

https://www.sdn.sap.com/irj/sdn/bpx-grc

SAP BW Accelerator Governance Process


© 2009 SAP AG 2

Table of Contents

BWA Introduction ................................................................................................................................................ 3

Audience & Recommended Use ..................................................................................................................... 3

Need for Governance ......................................................................................................................................... 3

When BWA ...................................................................................................................................................... 4

Activities Required .............................................................................................................................................. 4

Hardware Vendor Activities ............................................................................................................................. 4

Recommended Activities by BWA Admin ....................................................................................................... 5

Activities by SAP BW Basis ............................................................................................................................ 6

Activities by BW Production Support .............................................................................................................. 7

Specialized Activities by BW Support team (Client Specific) .......................................................................... 8

Important Administration and Regular maintenance Activities ........................................................................... 9

Important Transactions ................................................................................................................................. 13

Common Errors ............................................................................................................................................. 13

Different Errors .............................................................................................................................................. 14

Conclusion ........................................................................................................................................................ 16

References........................................................................................................................................................ 16

Disclaimer and Liability Notice .......................................................................................................................... 17



© 2009 SAP AG 3

BWA Introduction

BWA leverages industry-leading technology specifically designed to boost performance for SAP NetWeaver BI 7.0. This is done by building a predetermined selection of InfoCubes which will reside in main memory (similar to a giant cache), enabling blazingly fast performance for queries that access these cubes. The BWA implementation can improve the query performance through sophisticated in-memory data compression and horizontal and vertical partitioning.

Audience & Recommended Use

The entire BW community using BW reports for Critical Business Reporting. The Stake holders involved during the implementation and later during maintenance.

Need for Governance

To Ensure high availability of BWA.

Minimum Downtime.

Availability of consistent Data.

Minimum Restoration Time in case of Malfunctioning.

Optimum BWA performance

Well defined ownership between different stakeholders

Well defined process flow between different stakeholders

Tracking growth of BWA in a planned way to avoid surprises and huge impact.

Actually many stake holders involved during the implementation of the BWA as well as even later to maintain the BWA indexes and hardware. So there should be proper coordination required between the various stakeholders involved as well as proper defined responsibility should be in place like who is responsible for what?

So Governance of BWA streamlines the activities required to ensure the high availability of BWA with consistent data. All the activities have to be done by one of the stakeholders at some frequency.

Generally following stakeholders involved in BWA Administration, Configuration and Maintenance activities

Hardware Vendor

Basis support team

BW support team



© 2009 SAP AG 4

When BWA

i. Info cube containing very high amounts of data (more than 75 million rows to start with)

ii. Many Queries that have to scan the whole table for execution

iii. Aggregates are not a useful option/not able to give required performance

iv. Maintaining Aggregates becoming too costly and tedious

v. Concurrent users trying to execute the report and dis-satisfied with performance

The BIA only improves the database manager time, not OLAP time. So, before suggesting to client for the BWA option, the data manager time and OLAP time has to be checked for the Query.

The database manager time would be around 5 sec after adding the cube on BIA.

Notes: Check for more detail http://www.sdn.sap.com/irj/sdn/bia

Activities Required

Hardware Vendor Activities

Sl No Activities Frequency

1 Installation of the BI Accelerator On Demand

2 Installation of the BIA Software. On Demand

3 Updating and Patching the Operating System, Storage Components and File System Components.

On Demand

4 Administrative Tasks on Demand. Implementation of BWA Backup Blade Server concept.

On Demand

5 Starting and Stopping the BI Accelerator On Demand

6 Starting and Stopping Sequence of Blades On Demand

7 Booting the Blades of a BIA Landscape On Demand

8 BI Accelerator Backup and Restore On Demand

9 BIA Network Administration On Demand

10 Upgrading the Hardware/Addition of Blades etc On Demand

http://www.sdn.sap.com/irj/sdn/bia



© 2009 SAP AG 5

Recommended Activities by BWA Admin

Sl No Activities Priority

1 Change RFC connection to Local Gateway Very High

2 Update BWA software to the latest revision 53 High

3 Enable automatic adjustment of the number of RFC server instances and threads

High

4 Deactive Alert checks that should not run; also adopt recommendations for current alerts.

High

5 Adjust system time on BWA blades High

6 Implement recommendations for query runtime High

7 Maintain E-mail address for BWA to BW failover settings High

8 Update BWA system check scripts and run it again Medium

9 Update the database statistics, execute the Index Check again and reindex the indexes, if still errors or warnings are reported.

Medium

10 Consider archiving or removing large trace files that no longer needed

Medium

11 Consider increasing PKGSIZE to 100M for better indexing performance

Medium



© 2009 SAP AG 6

Activities by SAP BW Basis


1 Maintaining the RFC connection Initial Administrative Tasks/Malfunctioning

2 Configuring the TREX alert server for the BI Accelerator One Time activity recommended

3 Regular Administrative Tasks: Monitoring the BI Accelerator Daily

4 Check BIA availability (connection between BI and the BI Accelerator) by executing the BIA connection availability test

Daily (Implement alert and mail notification)

5 Check the basic BIA settings by executing the BIA system check.

Daily

6 Configuring database failover alerts One Time activity recommended

7 Setting up the BIA service connection (OSS) Initial Administrative Tasks/Malfunctioning

8 BIA availability monitoring. Daily

9 BIA optimization check for new features, notes, patches to keep BIA in a optimized state.

monthly



© 2009 SAP AG 7

Activities by BW Production Support

SL No Activities Frequency

1 Analyzing and Repairing BIA Indexes – RSDDBIAMON Daily

2 Identify BIA candidates On Demand Depending on the availability of BIA space

3 Modify existing Process chains for introduction of Roll Up steps On Demand

4 Simple BIA Functionality Check (RSRV), Process Chain should run with this check , including automatic mail notification

Daily

5 Optimize BI Accelerator(Re organization of Indexes); (especially cubes with deletion of requests)

Weekly

6 BIA usage statistics collection and analysis – How Cubes are used Monthly

7 Check the workload on the BIA hosts with the BIA load monitor Daily

8 Capacity Planning Monthly



© 2009 SAP AG 8

Specialized Activities by BW Support team (Client Specific)


1

Check Process Chain result

Check red and yellow requests in RSMON and reload them proactively Check load dumps in ST22

Daily

2 Check result of standard checks (done via TREX) and solve issues RSDDBIAMON2 Daily

3

Consistency Check

RSDDBIAMON GOTO -> Consistency check

Case by Case: (MUST)

- new patch

- Full load of cube

4

Overview BIA Indexes, Last update

RSDDV BIA Indexes

Daily

5 RSDDBIAMON2 Summary Tab Check for Status Daily



© 2009 SAP AG 9

Important Administration and Regular maintenance Activities

1. Add Roll up step in the process chain to automate the creation the delta Index just after loading of data to Cube happen. It is recommended to have recreation of Index (deleting and recreating of the BIA index) for the cubes which have full load on weekly basis.

Roll up of BIA indexes step will load the data of the request into BIA indexes. Whenever there is full load, the Roll up step will create the BIA indexes for all the records but delete overlapping request does not delete the BIA indexes for the overlapping request. So the size of BIA index will unnecessarily keeps on increasing. So it is necessary to reorganize the BIA index on weekly basis for full load cube to free the space.

2. Deactivate the aggregate, if any, for the cube added into BIA.

Step for General Roll up of BIA indexes

Step for Deleting and recreating BIA index

This will direct the next step based on current day. Generally Fill BIA indexes done on weekend and Roll up of BIA indexes done on daily basis.



© 2009 SAP AG 10

3. On daily basis, monitor the RSDDBIAMON2

4. For switching off/on for the BIA indexes for queries

5. Maintain the central repository for the BIA

Cubes on BIA

Load detail for the cubes on BIA

Switched off list of the cubes

List of BIA Cubes having full load and having step initial activation and filling of BIA indexes

This should be always green

Error and description will appear here



© 2009 SAP AG 11

6. Check the blade memory consumption on regular basis and before adding the new cube

Index server is used to find the memory consumption for BIA blades

Memory consumption should not be more than 50%.

The other 50% is mainly used for 3 operations

1. delta indexes, merge operations

- In these operations temporary objects are created which are ‘switched’ when the operation is finished, but in the meantime they are consuming resources

2. queries, in two ways store of temporary objects before sending the data the generation of the data itself

3. Memory is used for TREX internal processes

- One of the features of TREX is the use of multiple resources, but to keep the coordination going a lot of internal communication and information exchange happens.

TREX is also known for memory leaks.

Version 52 is much better that earlier version wrt memory leaks, although it still happens.



© 2009 SAP AG 12

The best place to see the memory consumption of Blades is through the TREX Admin Tool Summary tab. You can use this for future BWA sizing and reporting. The Value 28% shown below should be taken as appropriate memory consumption.

7. BIA sizing - SAP note 917803 – run the program ZZ_BIAMEMCONSUMPTION_BW3X

As per SAP, the compression ratio (The cube size/BIA index size for the cube) would be around 5:1 and the utilization should be 50% only. This can give the approximate size of blade memory required when cube is planned to be added.

You can use the program RSDDTREX_MEMORY_ESTIMATE for the memory estimate on BIA.

It allows to combine/select all relevant Cubes, takes into account shared master data and takes into account compression on F- and E-fact tables.

8. Update BIA index after master data/hierarchy changes



© 2009 SAP AG 13

Important Transactions

Common Errors

1. Reorganize BIA landscape - The server or the blades are loaded unevenly. If the status of the check is "red", you should reorganize to improve utilization.

2. BIA index server error – Index server is responsible for indexing, classifying and searching. The BIA index. Index server restart should be done on weekend and at the time when there is no Roll up for BIA indexes happening for the cube.

3. BIA server connection failed – Inform basis to check and ensure connection is in place.

4. While running the query, following error is observed



© 2009 SAP AG 14

Solution - Increase the size of the allowed compressed data package. This is the parameter "ICM/HTTP request size" in the profile of your appserver(s). (Reference – SAP 1077782)

In the profile of appserver(s) configure the following parameter:

o 'icm/HTTP/max_request_size_KB=<new memory size in KB>‘

o For the BI Accelerator max_request_size_KB = 1GB (1 048 576 KB) should be sufficient.

Also configure this parameter on every application server.

Restart the appserver (s) is needed.

Different Errors

1. Sometimes in the BIA Monitor Screen you see as error as shown below.

As particular table (info object) is not getting indexed along with the normal process. This should not be left like that. We need to identify the cubes where this info object is used. This would eventually lead to the roll up step not being performed and the Cubes not ready for reporting. This would have serious impact if suddenly we observe on a Monday Morning that cubes are not ready for reporting.

To resolve this issue we should follow these steps.

a) Please goto python Trex Admin Tool -> Index -> Landscape -> Action ->Check Consistency -> Repair

b) If step (a) do not solve the issue, please logon your BW system, then follow the SAP Note 1098260 to run RSDDTREX_SINGLE_TABLE_INDEX for this s-talbe.

There is a caution to use the second step as this is not released for all.

2. It is also observed that the memory consumption across blade is not equally distributed in the memory consumption details

The explanation here is that

o Blade1-2-3 have ALWAYS a higher memory utilization

o Delta update and merge operations of indexes

o Re-distribution of index-parts over the blades

o A part of the memory is spent on the coordination between the blades



© 2009 SAP AG 15

o The details shown in the BIA Monitor is partly static (summary) and partly dynamically (memory utilization per blade)

3. Sometimes we face errors like one below.

This can be taken care with the Process Chain. The Reorganize step will happen after the Roll up step of Process Chains. Detailed documentation is still not available.

4. BIA Server is Overloaded

Sometimes we get this error even if the summary tab of TREX Admin Toll shows that the memory consumed is 40%..

The possible root cause might be some query extracting more than 2 GB of data from the Cubes which are on BWA. The resolution happened with the BWA server restart.



© 2009 SAP AG 16

Conclusion

The general recommendation from SAP is that Use only 50% of the memory of Blades

The other 50% memory is used for

o Reporting

o Delta update and merge operations of indexes

o Re-distribution of index-parts over the blades

The new revision is released from SAP almost every month. Now we have revision 51 and dates of 52 has been released. Please check the compatibility before requesting for new release.

o Note 1148111 - BIA Revision / BI Support Package - Compatibility

SAP has announced that the BWA will be able to index data from ODS/DSO. This functionality is planned to be available from December 2009 onwards. This feature will be enabled with the BW 7.2.

References

http://hpdm08.isti.cnr.it/pres/lehner.pdf --

http://help.sap.com/

http://www.sdn.sap.com/irj/sdn/bia -- This has presentation describes the architecture, configuration, and administration of BI Accelerator in detail.

For more information, visit the Governance, Risk, and Compliance homepage.

https://service.sap.com/sap/support/notes/1148111

http://hpdm08.isti.cnr.it/pres/lehner.pdf

http://www.sdn.sap.com/irj/sdn/bia

http://www.sdn.sap.com/irj/sdn/bpx-grc



© 2009 SAP AG 17

Disclaimer and Liability Notice

This document may discuss sample coding or other information that does not include SAP official interfaces and therefore is not supported by SAP. Changes made based on this information are not supported and can be overwritten during an upgrade.

SAP will not be held liable for any damages caused by using or misusing the information, code or methods suggested in this document, and anyone using these methods does so at his/her own risk.

SAP offers no guarantees and assumes no responsibility or liability of any type with respect to the content of this technical article or code sample, including any liability resulting from incompatibility between the content within this document and the materials and services offered by SAP. You agree that you will not hold, or seek to hold, SAP responsible or liable with respect to the content of this document.

sap bw accelerator governance process

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