CA Agent Technology Best Practices › Performance Considerations

Performance Considerations

Adequate CPU

Agent Technology is a time critical application. To ensure your CA NSM workstations receive timely responses to their information requests, the necessary software components must receive adequate CPU cycles to process the workload.

These components include:

• The TCP/IP region running on the mainframe
• The Agent Technology Services (and OMVS itself)
• Any (all) z/OS-based agents

This typically means running these components in a high priority performance group, equal to that of other main systems and started tasks (for example, JES, VTAM, CA Top Secret, and so on).

The Object Store Database

The cache sizes of the object store database can be adjusted to minimize I/O EXCPs if the need arises.

There are a total of 22 files that comprise the aws_sadmin object store database.

These files are found within directory

$AGENTWORKS_DIR/services/var/aws_sadmin

and can be categorized into the following groups:

• Objects table—6 files prefixed with OBJECTS.
• Titles table—6 files prefixed with PROPTH.
• Properties table—6 files prefixed with PROPVH.
• Votree table—4 files prefixed with VOTREE.

The size of these files depends on the following:

• The number of MIBs loaded in the object store
• The size and number of configuration sets loaded in the store
• The number of agent instances currently running

To minimize the number of EXCPs used to access the object store, the following parameters have been added to the aws_sadmin startup command. The startup of the aws_sadmin service can be found in file awservices.cfg, within directory services/cfg/awservices.

• -x <cache-size for the objects table>
• -y <cache-size for the properties table>
• -z <cache-size for the votree table>

No parameter has been established for the Titles table, since the default value should be adequate for all sites. All cache sizes are expressed in KB. When left unspecified, the default value for all three parameters is 1024.

To minimize I/O EXCPs to the object store database, you must set the cache size parameters to the total size of all of the files within each of the different table categories (with the exception of the rollback files, which are suffixed with MMA, RBI, MM2, and RB2). Listed below are the calculations you should perform to determine the size for each of the cache parms:

• -x

  Sum the size of the following files (Divide the result by 1024 to convert to KB):

  OBJECTS.CHK
  OBJECTS.FBM
  OBJECTS.MDI
  OBJECTS.MDS
  

• -y

  Sum the size of the following files (Divide the result by 1024 to convert to KB):

  PROPVH.CHK
  PROPVH.FBM
  PROPVH.MDI
  PROPVH.MDS
  

• -z

  Sum the size of the following files (Divide the result by 1024 to convert to KB):

  VOTREE.CH2
  VOTREE.CM2
  

Note: These calculations should be performed only after all MIBs have been loaded and all agent instances have been started. You must ensure that your AT z/OS Services have been shut down before you attempt to modify the awservices.cfg file (otherwise your changes will not be preserved).

Statistics Collection

As noted previously, earlier, the aws_sadmin service is responsible for the processing all of SNMP requests coming in from the various CA NSM components, as well as for the generation of SNMP traps. In addition to these functions, the aws_sadmin service also maintains the awsAdmin MIB and the associated awsAdmin agent. The awsAdmin MIB contains the following categories of information:

• Configuration information
• Agent and MIB information
• Statistical information

The statistical information is collected in the following different groups:

• AwsAdminAgentGroup
• AwsAdminSnmpGroup
• AwsAdminPerfGroup
• AwsAdminSourceGroup

The maintenance of the statistical information within the awsAdmin MIB represents an appreciable amount of work for the aws_sadmin service. In fact, benchmark tests have shown that as much as 40% of the CPU time spent by the aws_sadmin process is consumed by the updating of all of these statistics.

As a performance-enhancing feature, the following environment variables have been added to control the collection of the statistical information within the awsAdmin MIB. These environment variables let you turn off the collection of any (all) statistics, resulting in the reduction in CPU (as well as increased performance) for the aws_sadmin service.

The environment variables, along with their possible values, are as follows:

AW_ADMIN_STAT_AGENT=ON/OFF
AW_ADMIN_STAT_SNMP=ON/OFF/NOTOTAL
AW_ADMIN_STAT_PERF=ON/OFF
AW_ADMIN_STAT_SOURCE=ON/OFF

The default value for each variable is ON. If you want to change this value (to improve performance and reduce CPU overhead), define the environment variable within the agentworks.profile file in the root Agent Technology directory ($AGENTWORKS_DIR) of your zFS system.