SAP Table Logging

Table logging is a functionality SAP provides to automatically track changes on tables set as "LOG DATA CHANGES".
By default SAP delivers mainly config tables set like that since the main reason was to enable automatic logging of config changes.
The functionality could indeed harm your system performance but , as per OSS note 608835, you should not have problems since only config tables are set to be logged...
"Generally, you can activate logging in your system without any problems because SAP only delivers Customizing tables with activated logging. Customizing tables usually contain a relatively small amount of data which is only changed occasionally.
To be more precise: Basically all Customizing tables are delivered with activated logging because the requirements of external auditors are inconsistent as regards the logging of tables.
Tables for master and transaction data, on the other hand, are delivered by SAP without logging indicators. A large number of these tables are subject to mass changes which would cause performance problems if they were logged. You should use great caution if you want to log any of these tables.
Practice has shown that, bearing the above restrictions in mind, logging does not cause any problems in the production, Customizing and development environments.
If performance or memory problems occur unexpectedly, you can easily determine which table causes the problems:
Select the "Administration --> Number of logs (selective)" menu option (Shift+F8) in transaction scu3. Enter a time interval in the selection screen displayed and leave the table selection empty. If you now start the report, it returns a list of all logged tables with the number of recorded logs. You can then deactivate the logging of the tables most frequently logged in transaction SE13.
As described above, SAP delivers all Customizing tables with activated logging. Due to the relatively low number of changes in Customizing, it is not useful to remove the logging indicator from all tables except a selected few, especially since the requirements for the logging of pages may be changed by your external auditor from time to time."

If you want to monitor changes in application tables, you need to rely on aplication change objects. Ex: for table MARA, we don't have it set to auto changes, yet, we have the log of changes through standard change objects, programmed within the standard MM02, MM01... transactions.

AIX tools for SAP Administrators Set 5

Check APAR Level
instfix is used to install filesets associated with keywords or fixes.
instfix -i | grep
***********************************************************************************
Check concurrent io settings on oracle filesystems
lsfs |grep cio
To change the filesystems to CIO mounts execute the following scripts
Script1:
lsfs -c |grep sapdata|cut -d":" -f 1|while read f
do
chfs -a options=cio $f
umount $f
mount $f
done
Script 2
lsfs -c |grep [mirr,orig]log[A,B]|cut -d":" -f 1|while read f
do
chfs -a options=cio $f
umount $f
mount $f
done


***********************************************************************************
Setting Max Processes allowed per User
The parameter maxuproc defines this.
To check the current value
lsdev -El sys0
To change the parameter maxuproc
chdev -l sys0 -a maxuproc=
***********************************************************************************
 The xhost program is used to add or revert access to the X server for specified hosts. This connection / port is used by VNC, X Manager.
All connection from all the server with the following command
xhost +
or
xhost +
***********************************************************************************
slibclean
/usr/bin/slibclean
Removes any currently unused modules in kernel and library memory.
This unloads all object files with load and use counts of 0. It can also be used to remove object files that are no longer used from both the shared library region and in the shared library and kernel text regions by removing object files that are no longer required.

Near Zero Downtime Upgrade

Here's a brief steps for accomplishing a near zero downtime upgrade.


1) A golden client is built with ERP 6.0 built. SPAU/SPDD is done and is relaible
2) Table logging in turned on in the source release since that date.
3) The tools keeps flushing the delta between the two systems. Here the tool manages the strucure changes and others for standard SAP objects. For custom tables or any special add on's, you have to provide the list.
4) A 2 - 6 hour outage for the last delta to be flushed out.

But this is still in testing phase in SAP Labs.

Best Technical Practices for SAP Landscape Maintenance

In this post I would like to share my experience on Proactive measures to be taken in a SAP Landscape.

The recommendations are slightly biased towards technical aspects of SAP; hence I would request the readers to only apply them in your own environment after a careful analysis. Thanks for it!

You are most welcome for your suggestions and corrections.

I would like to divide the main topic into 7 sub-components

•     Proactive Measures
•      Performance Optimization
•      Disaster Recovery
•      Problem-Solution Approach
•      Onsite vs Off-shore Support Delivery
•      Upgrades
•      System copies

Proactive Measures

This section emphasizes on key recommendations on preparation aspects to be satisfied for ever-challenging and ongoing performance tuning by Basis, ABAP and Functional Leads. These recommendations might give an impression that they would involve efforts during the initial stages of practice. But indeed this practice yields fruitful results once put in practice. Patience definitely pays! I would also be helping out in getting the intended results indeed by giving examples and code wherever necessary. Before I start just want to ensure the readers that this model works PERFECTLY if basis team works at a client place or close to the client environment. In off-shore support model, implementing these recommendations would be slightly tough. Though, the decision is left for you to decide which of them best suits your needs. I believe now I am ready go into topic.

1. Technical review Tracker:

This can be a Power-point presentation or a Word document depicting the technical aspects based on which the tuning, enhancements and changes can be decided. This presentation is updated twice in month by the Basis Team and will be reviewed by the Technical lead, Functional leads and other influencing persons. The objective of periodic reviews of this presentation would be to achieve the intermediate goals set during the review meetings. Let me be more specific about this presentation. The following are the slides that can be used for this presentation. Keep in mind that this presentation is unique to each SAP system landscape like ECC, BI, PI, SOLMAN, CRM, SRM etc.

1. Hardware Details

2. CPU Utilization of Primary, Additional Apps, Database servers

3. System landscape and the transport route

4. Database space management

5. Buffer Invalidations

6. Top Background Jobs

7. EarlyWatch Recommendations

I would give a brief about each of the above on how it works. H/W details slide shows hostname, RAM, physical/virtual CPUs on the LPAR/Server, CPU entitled capacity, IP address etc. CPU Utilization slide would help in identifying the CPU power bottlenecks and under utilization of CPU. This helps in identifying the SAP components causing the maximum utilization there by optimizing the total performance of the server and also reorganizing the logon groups. This helps especially during month-end releases and COPA activities which imposes maximum impact on the total server performance. Now, database space management slide. As we all know this is very crucial for the overall performance of the SAP server.

Script for killing all processes matching a search string!

ps -e -o ":%p:%a" | grep | cut -d":" -f2|while read p
do
echo processes $p
kill -9 $p
done

NetWeaver Installation Part II

32. What are sapadm, adm and webadm used for?

A. sapadm is used for Central monitoring services. adm is dedicated to Diagnostic agent installation. webadm is created to use web administration interface for Internet Communication Manager (ICM) and web dispatcher.

33. How to prepare SAP system for NWDI integration?

A .           If you select check box Prepare SAP system for NWDI Integration on the screen NWDI Landscape, SAPinst copies all SCAs belonging to the software units that you installed to the global transport directory.

The SAP NetWeaver Development Infrastructure has a set of services that provide central storage and distributed versioning of Java source code, plus centralized build services and a predefined change management process that control the folow of the software through the landspace. To integrate your SAP system into the development landscape, NWDI requires all installed software components to be available in the file system.

34. How do you plan the Switchover Cluster?

A.            To reduce unplanned downtime for your SAP system by setting up a switchover cluster. This setup installs critical software units - know as "single points of failure" (SPOFs) - across multiple host machines in the cluster. In the event of a failure on the primary node, proprietary switchover software automatically switches the failed software unit to another hardware node in the cluster.

Manual intervention is not required. Applications accessing the failed software unit might experience a short delay but can then resume processing as normal.

Switchoever clusters also have the advantage that you can deliberately initiate switchover to free up a particular node for planned system maintenance. Switchover solutoins can protect against hardware failure and operating system failure but not against human error. 

35. What a switchover cluster consists of?

A.

1. HW cluster of two or more physically separate host machines to run multiple copies of the critical software units, in an SAP system the SPOFs referred to above. 

2. Switchover software to detect failure in a node and switch the affected software unit to the standby node, where it can continue operating.

3. A mechanism to enable application software to seamlessly continue working with the switched software unit - normally this is achieved by virtual addressing.

 

  

36.  How do you manage the creation of operating systems users during the SAP installation in the case of NIS (Network Information System)? 

A. 

SAPinst checks if the required services are available on the host and creates them if necessary. See the log messages about the service entries and adapt the network-wide (NIS) entries accordingly.

SAPinst checks the NIS users, groups, and services using NIS commands. However, SAPinst does not change NIS configurations.

For a distributed or a high-availability system, its recommended that you distribute account information (operating system users and groups) over the network by using NIS.

Note: If you use NFS-V4 file system, you have to create the ora user on the NFS server.

37. Directory structure of ABAP+Java System.

AIX tools for SAP Administrators Set 4

Some really funky hardware-looking problems can be fixed by draining
the NVRAM battery for 5 minutes, and then reinstalling the microcode.
We used to do this on some IBM RT's in Cincinnati, and a recent poster
to AIX-L indicates that it's still useful in some situations.

Why don't you try using iptrace and ipreport to see the behavior of your
telnet sessions ??

/usr/bin/uname -M
Gets the machine type

acledit