Monitoring the Change RunVersion 2.0 – BI 7.0

Monitoring Tasks

FAQ

Changerun Basics

Monitoring Transactions

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Attribute and Hierarchy Changerun

Attribute and Hierarchy ChangerunThe attribute and hierarchy changerun is required to

activate master data changes to attributes and hierarchies

realign aggregates containing navigational attributes

realign aggregates defined on hierarchy levels

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If you change master data (navigation attributes) or hierarchies of a characteristic that is contained in aggregates, you must adjust these aggregates.

This ensures that queries that access to the InfoCube or assigned aggregates are consistent. Unlike in the aggregates, no data that refers to navigation attributes or hierarchies is stored in the InfoCube.

The master data or the hierarchy tables are joined with the tables of the cube when the query is executed. Regardless of whether or not aggregates exist, the system does not automatically transfer master data record changes, rather you must activate this master data explicitly.

Attribute and Hierarchy Changerun

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Activation of Attributes in Detail

InfoObjects are automatically assigned by the system

Method 1: ‚Manual‘ activation (only possible if no aggregates are existing, otherwise: method 2)

Method 2: Automatic activation by Change Run

Active data in master data tables and aggregates

Active data in master data tables and aggregates

Activation of Master data Attributes

recommended

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3000 M Chemical

4000 A Chemical

Attribute and Hierarchy Changerun – Example

Country Customer Key Figure

USA 1000 10

Germany 2000 15

USA 3000 5

Austria 2000 10

Austria 4000 10

Germany 3000 20

USA 1000 25

Fact Table Sales Data

Customer__Industry Key Figure

Pharma 60

Aggregate Customer__Industry *

Retail 25

Chemical 10

Customer OBJVERS

1000 A

Navigational Attribute of Customer

2000 A

3000 A

Industry

Pharma

Retail

Pharma

Changed master data not available

for reporting

The impact in the aggregates is always because the navigational attributes (xxx__navattribute)

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4000 A Chemical

Attribute and Hierarchy Changerun – Example

Country Customer Key Figure

USA 1000 10

Germany 2000 15

USA 3000 5

Austria 2000 10

Austria 4000 10

Germany 3000 20

USA 1000 25

Fact Table Sales Data

Customer__Industry Key Figure

Pharma 35

Aggregate Customer__Industry *

Retail 25

Chemical 35

Customer OBJVERS

1000 A

Navigational Attribute of Customer

2000 A

3000 A

Industry

Pharma

Retail

Chemical

Changed master data now available

for reporting

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Strategies to Adapt Aggregates

There are different strategies to adapt aggregates in a changerun:

Rebuild the aggregate Delta Mode Rollup from previously adapted aggregate (Parent ->Child Aggregates)

For InfoCubes containing key figures with aggregation MIN/MAX, the only way to adapt the aggregates in a changerun is rebuilding them.

The value 'Limit with Delta' determines the percentage of master data changes at which the delta mode is to be switched to reconstruction.

Changed to

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Aggregates - Blocksize

Read in several blocks to prevent resource problems when filling an aggregate

During rollup and Change Run high resource consuming operations on the temporary tablespace can be performed.

PROBLEM PSAPTEMP SIZE

Idea

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NEW : Wait Time

Wait Time: An immediate Change Run start may not be possible because other processes hold necessary locks (e.g Master Data Loading, Roll Up, …)

The Wait Time specifies the time in minutes how long a Change Runs waits before terminating.

Hard-Coded Time: Other processes locked by a changerun in STARTUP-phase wait per Default 5 min. (not changeable)

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NEW : Parallel Change Run in NetWeaver 2004s

New since NetWeaver 2004s:- Change Runs are executed only with background processes

- The parallel degree can be set in Customizing or transaction RSBATCH

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NEW: Parallel Change Run in NetWeaver 2004s

1. Adjustment of Aggregates

2. Activation of Master Data

3. Compression of Aggregates

Maximal N-1 parallel jobs

Maximal N-1 parallel jobs

Maximal N-1 parallel jobs

• The Change Run combines different steps which are processed sequentially

• Each of the steps is restricted by the maximum number of parallel jobs (N) chosen in Change Run Customizing

• There is 1 Managing job • There are maximal N-1 working jobs

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Technical details about Change Run

Step 1 (usually less than 1min): When the Change Run starts a global SAP enqueue lock is set. This global lock is hold just for a short time until the affected infocubes are identified. This global enqueue lock doesn’t allow

– any master data loads to InfoObjects – starting another Change Run– rollup to an aggregate

Step 2:After the global lock was removed just a smaller enqueue lock is set. It locks just the affected Infoobjects and the InfoCubes where the infoobject is used. Furthermore some activities are not allowed during the Change Run works

– master data loads to the affected InfoObjects, but master dataload to other InfoObjects

– rollup for InfoCubes having aggregates affected by the Change Run

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NEW:Change Run in Netweaver 2004s

Two or more Change Runs in WORK-Phase can run in parallel (if the Change Runs process different objects)

There can be only one Change Run in STARTUP-phase– A second Change Run waits up to 5min to get the lock for STARTUP (hard-

coded)

– Other blocked processes (e.g Master data loading) wait as well up to 5min (hard-coded) for the Change Run

The locks for Change Run are set/checked on InfoCube level (in former releases on aggregate level) The RSADMIN-parameter CR_MAXWAIT was replaced by Customizing

– Default = 1min

New Change Run Lock Concept with NetWeaver 2004s :

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NEW: Parallel Change Run in NetWeaver 2004s

Change Run Concept since NetWeaver 2004s

Time

Change Run 1

Change Run 2

STARTUP WORK

NEW !!Two Change Runs can run in parallel if affected objects are different

Max. 5min

Time

Change Run 1

Change Run 2

STARTUP WORK

NEW !!Change Run does not terminate immediately if another Change Run is in Startup

NEW !!Second Change Run does not set global lock when waiting for another Change Run.

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Keep in Mind….

The length of the change run depends on several factors:

Amount of master data to be changed Amount of hierarchies to be adapted Number and size of aggregates and their basis infocubes

General load on the system Status of the database (statistics & indices) number of partitions in Source Cube (F-Table)

Monitoring Tasks

FAQ

Changerun Basics

Monitoring Transactions

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Changerun Transaction

The central transaction to the changerun is RSATTR or

RSA1 Tools Apply Hierarchy/

Attribute Change…

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InfoObjects and Hierarchies to Be Activated

The changerun is always started for a set of InfoObjects and/or hierarchies.

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Information on Background Jobs

The frame 'Applied hierarchy/attribute change runs’ shows information on background jobs: Changerun Status Start and end date Start and end time User Job name

Transaction SM37 always shows times in UTC format whereas the times in the changerun transaction are converted to the time zone of the user.

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Application Log

The application log shows information about the InfoObjects and hierarchies to be activated, number of changed characteristic values and adapted aggregates.

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Changerun Monitor

The changerun monitor shows information about the current status of the changerun, the InfoObjects and hierarchies to be activated, the affected aggregates and how they were/will be adapted.

The changerun monitor is displayed in a separate window be Patient.

Ignore the message about missing authorizations.

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Changerun MonitorThe changerun monitor ( RSDDS_CHANGERUN_MONITOR) shows information about the current status of the changerun, the InfoObjects and hierarchies to be activated, the affected cubes and no. of object changes ,affected aggregates and how they were/will be adapted.

The changerun monitor is displayed in a separate window be patient.

Ignore the message about missing authorizations.

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Standard Changerun Monitor

Status of changerun

Basic Characteristics with modified master data to be activated

Object changes in Infocube to be updated

Aggregates which have to be adjusted during the changerun including mode: delta, rollup, reconstruction

Some info below will be available after clicking the Details button

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Terminated MonitorIn case the ACR terminates by any reason, after resolving the issue you can repeat the failed step in the process chain or restart it via the Change Run Monitor

The changerun monitor is displayed in a separate window be patient.

Ignore the message about missing authorizations.

Click here to restart the terminated ACR

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Using Statistical Information before Deactivating Aggr

Fields of table RSDDAGGRDIR

INFOCUBE Infocube name

AGGRCUBE Aggregate name

NUM_AGGR Number of Components

NUM_ENTRIES Number of Records in the Aggregate

CALLS Aggregate usage (if low it is a candidate to be deleted)

LAST_CALL Last time the aggregate was used

AVGFACTREDUCEMedium dividing the cube records per aggr records. If equal to 1, means aggr same size as the cube

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Statistical Information on Adjusted Aggregates

Still in the table RSDDAGGRDIR selecting “INA” in the column Object Status (OBJSTAT) and “A” in the column Version it is possible to analyze which aggregate is being adjusted at the ACR time. This way, IF NEEDED, you can deactivated just the aggregates that are being adjusted not ALL aggregates.

Analyzing the table RSDDAGGR_V you can see which aggregates are going to be impacted by the Change Run Process before the ACR job to adjust those infoobjects start. You must select those entries in “M” version

Analyzing the table RSDCUBEIOBJ – Verify which infoobjects are being used by aggregates

Monitoring Tasks

FAQ

Changerun Basics

Monitoring Transactions

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Monitoring Tasks

Monitoring TasksWhile monitoring the system, one of the following questions may arise

What is the status of the changerun?

How should I restart a cancelled changerun?

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Changerun Status – Step 1

Status of Background JobIn transaction SM37, select jobs starting with 'BI_STRU' or 'BI_PROCESS_ATTRIBCHAN‘ which are the Parent Jobs

The Child jobs start with

BICHNG* (Job to adjust/rebuilt Aggregate)

BIACTI* ( Job to activate the Info object )

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Changerun Status – Step 1

Based on the Parallel settings you could see Multiple jobs running. Currently its set to 16 BTC processes in parallel.

Pls note that When a BICHNG* job fails, the Parent Job Automatically repairs and adjusts the aggregate in the failed job.

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Some more in depth tips (1)

1) To get stats on Info Objects concerned and Aggregates touched:

1.1.Condition : all Process Type ATTRIBCHAN will have to be preceded with Custom Process Type ZGTTC_CR and ACR will not be run directly (via Tools>Mdata Activation = job type BI_STRU*).

1.2. In Table RSDCUBEIOBJ (or RSDDAGRR_V (version ‘M’), find out the aggregates that presents the high number of master data changes.

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More in depth tips (1.2): Nav Attributes : where used (aggregates)

select Infocube [*] Y5 with version ‘A’ and InfoObject = YMAT_COMP__0MATL_GRP_1

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Some more in depth tips (2)

2) To get all ACR background jobs (manual or PC trigerred) in proper sequence with Start Time, End Time and Process Chain Id.

Use SE16 on view V_OP with selection on jobname

BI_STRU*

BI_PROCESS_ATTRIBCHAN

BICHNG*

BIACTI*

A = Abort

F=Finished

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Typical Reasons for Cancelled Changeruns

In transaction SE16, table RSDDAGGRDIR, find the InfoCube on which the aggregate is defined:

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Typical Reasons for Cancelled Changeruns

In transaction RSDDV, enter the InfoCube name and deactivate the aggregate:

Then, restart the changerun from the log view of the process chain:

Monitoring Tasks

FAQ

Changerun Basics

Monitoring Transactions

SAP AG 2006

FAQ

Is there an alternative to deactivating an aggregate in order to solve changerun problems?

If the changerun gets stuck with an aggregate, Please check if this Aggregate has been adapted for Reconstruction in the Change Run Monitor and if it is .. then you could go ahead and Deactivate it and fill it later on.

If obsolete DB statistics caused the problem, they can be refreshed in transaction DB20. However, the refresh does not affect the currently running SQL statement. Therefore, the current changerun must be cancelled and restarted. In this (rare) case, deactivating the aggregate may not be necessary.

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FAQ

Is it possible to activate master data separately from adjusting aggregates? If so, it would be possible to start critical process chains, which require up-to-date master data, without waiting for the end of the changerun. The aggregates could be adapted later once the critical process chains are finished.

There are function modules to activate master data which do not check whether aggregates are affected by the master data changes. However, in this case, it is not possible any longer to adapt the affected aggregates in delta or rollup mode. Then, all affected aggregates must be deactivated and re-filled manually.

It is obvious that this procedure involves a high risk of inconsistent data in aggregates (if one forgets to deactivate an aggregate).

Therefore, this procedure is not considered as an alternative to the changerun.

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FAQ

Is it possible to select which aggregates are activated as part of the changerun and which can be scheduled separately later?

As explained on the slide before, the approach to adjust aggregates separately from the master data activation involves a high risk and is not considered as an alternative to the changerun.

However, if the decision is taken to deactivate several aggregates in order to speed up the changerun, it is possible to select which aggregates are deactivated and which should be adjusted by the changerun.

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FAQ

How to tune the performance of the changerun?

1. Identify aggregates that are adjusted by rebuild during the changerun (table RSDDAGGRDIR Vers A, Stat = INA)or RSDDSTATAGGR .

2. Identify aggregates adjusted in delta or rollup mode with high changerun times and optimize the aggregate hierarchy.

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FAQ

Possible causes of poor performance

Poor modeling decisions – Maybe there are too many aggregates. You should check if you can delete any unused &

unnecessary aggregates. – Both a characteristic and it’s navigational attribute are used in the same aggregate

definition with * aggregation level (for example, 0CUSTOMER & 0CUSTOMER__0CUST_GRP). This is NOT recommended. It will increase the time of the change run. It is enough to only have the characteristic 0CUSTOMER in the aggregate definition. A query with a selection on 0CUSTOMER__0CUST_GRP will still access the aggregate, even though they have only included 0CUSTOMER in the definition!!

Too many uncompressed requests in the F Facttables of the infocube or aggregate

– On all database platforms it is strongly recommended to regularly compress infocube and aggregate data. For ORACLE it is particularly important. Check the number of entries in packet dimension table /bic/DxxxxxxP. A maximum number of 20 - 30 partitions (uncompressed requests) per F table are recommended. See note 590370. COMPRESS! COMPRESS! COMPRESS!

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FAQ

Possible causes of poor performance (2)

DB statistics are not up-to-date– DB statistics must be up to date for the database to choose the most optimal accesses

to the data. If statistics are not up-to-date, it could happen that you have a run away change run program that can never finish because of a poor execution plan.

Degenerated Indexes– Degenerated indexes can also cause longer runtimes as the data cannot be accessed in

the most efficient way on the database.

RSCUSTV8-DELTALIMIT is set too low or too high– SAP recommends setting this parameter to 20. This means that if less than 20 percent

of the masterdata of a characteristic has been changed, the aggregate will be changed with the ‘Delta’ method. If more than 20 percent has changed, then the aggregate will be ‘Reconstructed’ (or rebuilt completely). If the DELTALIMIT is set too high, it can take longer to adjust the aggregate using the delta method, as opposed to doing a rebuild. If it is set too low or not set at all, then all aggregates will be ‘Reconstructed’ during each change run.

Missing SAP Notes– Be sure to search for any relevant notes for the customers BW Support package level.

Good search terms for notes are Change Run or Realignment Run & BW-BEX-OT-AGGR.

– Don’t forget to look for DB related performance notes that refer to index rebuilding or statistics creation.

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FAQ

Additional ways to improve performance

Execute Change Run in Parallel..currently 16BTC are run in parallel

Schedule the Change Run when the system load is lightest– Heavy system load can cause the change run to take more time. Try to

schedule this job during periods of low or limited system activity.

Customize the BLOCKSIZE parameter – During the initial filling of an aggregate or the rebuild of an aggregate during

the change run, high resource consuming operations are performed on the temporary tablespace. Set the BLOCKSIZE parameter to read in several blocks to prevent resource problems when rebuilding an aggregate. Transaction SPRO –> General BW Settings –> Parameters for Aggregates -> Blocksize . This is a database dependent setting and should be tested by customers to determine the best performance when filling an aggregate.

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