IMS Monitor reports for DBCTL

This topic describes:

• The events that the IMS Monitor collects
• The content of the reports produced by the IMS Monitor Report Print Program

Monitoring has different meanings for DBCTL and DB/DC. For DB/DC, the end user enters the transaction on a terminal. The transaction is processed by IMS and then returns a result to the user. Transaction characteristics that are monitored include total response time and the occurrences of resource contentions (for example, PSB schedule wait time, and database I/Os).

DBCTL has neither transactions nor terminal end users. It does, however, work on behalf of transactions entered by CCTL terminal users.

A typical sequence of these DRA requests would be:

1. A SCHED request to get a PSB scheduled in DBCTL
2. A DL/I request to make database calls
3. A sync-point request, COMMTERM, to commit the updates and release the PSB

The DBCTL process that encompasses these requests is called a unit of recovery (UOR).

DBCTL provides monitoring data about UORs, such as: total time UOR existed, wait time for PSB schedule, and I/Os during database calls. This information is very similar to IMS transaction monitor data. In a DBCTL-CCTL system, however, the UOR data represents only part of the total processing of a CCTL transaction. Therefore, CCTL monitor data is necessary to get a total view of CCTL transaction performance.

DBCTL does not change the format or usage of the IMS monitor reports. There are reports and fields within reports that are not applicable to DBCTL. Generally, these are in the transaction manager and communication areas. There are some fields that are interpreted differently in a DBCTL environment.

For reports that do not apply to DBCTL, either a heading without data is shown or no report is generated. These reports are:

• Message Queue Pool report
• Message Format Buffer Pool report
• Communication Summary report
• Communication IWAIT report
• Line Functions report
• MSC Traffic report
• MSC Summaries report
• MSC Queuing Summary report

The term region in IMS Monitor reports refers to a PST assigned to a specific dependent region that processes specific IMS transactions. In DBCTL monitor reports the term region still applies to a PST. A PST can service one CCTL thread (transaction) at a time. However, CCTL threads change, resulting in one PST servicing many different CCTL transactions. Since multiple CCTLs can connect to DBCTL, the PST can actually service transactions from different CCTLs.

All of the threads built for a CCTL carry the job name of the CCTL. This appears as the same job name for many regions in the General Reports.

Within a trace interval, a thread can be assigned to multiple CCTLs, but it can only be assigned to one CCTL at any instant of time. So, depending on the number of CCTLs attached to DBCTL, the Region Summary reports can show:

• One region with only one job name.
• One region with different job names.
• Multiple regions with different job names. Some regions can have the same job name and some can have different job names.
• Multiple regions with only one job name.

Any monitor report for a region is a summary of all the CCTLs a thread served during the trace interval (for example, the elapsed time for all CCTLs that a thread has been assigned to during the trace interval).

The reports generated by the IMS Monitor are the same for BMPs and non-message BMPs.

UOR elapsed times are spent in DBCTL, not in the DRA. The time spent in the DRA is considered part of the CCTL, therefore the DRA time is not reported by any DBCTL statistics.