SirMon

SirMon is a system monitor and operations control utility for Model 204. It provides a centralized means for information collection, problem resolution, and systems tuning within the Model 204 environment. The flexible format of SirMon's expanded sets of system, subsystem, file, and user statistics are easily customized. The user interface links to a command set that supports timely and informed decision support and system control.

The clear organization of real-time information provided by SirMon eliminates the need to cross-reference data from multiple sources to determine the cause of problem situations. SirMon saves both time and human resources needed to perform System Managers and DBA functions. This increases the likelihood that problems will be resolved quickly.

Automated Monitoring and Problem Reporting

SirMon provides three levels of automated monitoring.

First, SirMon provides an auto-refresh mode for displays, that enables precisely timed presentation of performance statistics and permits a terminal to be set up as a " hands-off" system monitor.

Second, SirMon enables users to set thresholds for any statistic on the System Overview screen. The System Overview screen provides information about all key areas of system performance including resource consumption and response-time. When any statistic has exceeded its user-specified threshold, it is highlighted on the System Overview screen allowing System Managers to quickly identify any potential problems from a single screen.

The third level of automated problem reporting is performed by the SirMon background task, which runs as an IODEV3 user, monitoring system status and sending warnings when problems are detected. The background task uses the same user-specified thresholds as the System Overview screen. In addition, users can specify the monitoring interval, the number of intervals across which a problem must exist before SirMon sends warnings, a message-latency period that prevents excessive warnings, and a list of users (including the operator and the journal) to receive messages. The background monitor, combined with Sirius' expanded set of system measures-including a number of response-time indicators-provides timely and highly-detailed performance checking with very little user setup or manual intervention.

Dynamic User Restart

In those extreme cases where a single user is " looping" , and preventing other activity from occurring in the Model 204 address space, a restart option allows the operator to restart only the looping user from outside the on-line without affecting other " healthy" users. This provides a number of information-gathering options, and increases the likelihood that the on-line will continue to run or, if it must be brought down, that a recovery step will not be required.

System Managers

With SirMon, System Managers receive a clear picture of problems occurring within an on-line and of the results of the actions they may take to correct the problems. SirMon removes the guesswork from problem resolution. By using SirMon, the System Manager increases his or her knowledge of the local database environment and of the kinds of activity that indicate performance or operational problems.

File Managers

File managers and application designers will also find their workload eased by SirMon's ability to collect and present the precise information needed to develop and maintain database applications. Any resource which is capable of being adjusted, such as UTABLE settings, server size, or CPU, can be displayed along with the user, file, or procedure using the resource. File Table usage can be viewed in a single scrollable set of information for all files open in the on-line.

In addition to addressing these important day-to-day operational problems, SirMon provides information that is essential to fine-tune performance and evaluate the overall efficiency of an on-line configuration. Performance projects may target the system as a whole, or focus on specific applications, procedures, or internal resources such as servers, index structures, or subtask offload.

Examples of the operations concerns addressed by SirMon include the following:

• You want to free a file. How do you identify who's holding it? In SirMon you can monitor all users and then limit the display to only those holding open a specified file. The Subsystem monitor screens are used in exactly the same way to identify APSYs holding open a particular file.

• The checkpoint dataset regularly fills up. By monitoring users and limiting the display with a CHKP command, only those users preventing the checkpoint from taking place are displayed, along with any statistics you choose, (in this case, the procedure name and subsystem might be shown). This simple facility of monitoring on one entity and then restricting the view by another allows great flexibility in targeting specific enqueueing or performance situations.

• A long-running request prevents users from sharing the system. Usually there is little choice but to physically locate the person, find out what they're executing and make a decision regarding the user's session. With SirMon, the user, the level of resource consumption, the procedure, APSY, and file can all be seen instantly on a single screen. The user may still be bumped or the manager may reduce the user's priority (even to O) while the problem is investigated.

• You want to compare transaction rates against published benchmarks, or against those claimed by another application. SirMon allows you to view changes in any resource per screen I/0, per user-specified time interval, or per event that you define by 10 locally-defined and locally incremented event counters built into SirMon. SirMon's " hands-off" mode of operation allows sub-second precision in determining your transaction rates.

• A case has been made for changing the current mix of servers. A single screen in SirMon will show you the procedure each user is running, the size server they require and the size they got. The same process is used to show UTABLE settings in relations to procedures and users.

• Monitoring of file table usage takes too much time. SirMon reduces this task to mere seconds by displaying all file table usage information in all open files in a single set of data which can be scrolled and sorted.

SirMon answers performance and data availability questions that cannot be answered by other means. For example:

• What is your peak sustained transaction rate?

• How often do you have server swaps for things other than terminal I/O?

• Do you have critical file resource bottlenecks on any database files?

• What is the cause of these bottlenecks?

• Is the checkpoint or journal dataset ever a bottleneck on your system?

• How widely does CCATEMP utilization vary in the course of a day?

• How about record locking table utilization?

• Is your on-line getting all the CPU time it wants or needs at peak hours?

• How often do you do VTAM buffer waits?

• Does your on-line's virtual storage utilization vary over the course of the day?

• What is your peak sustained server I/O rate? What is your peak sustained database I/O rate? Do they occur at the same time?

• How much of your database l/O at peak times is CCATEMP I/O?

• What is your peak IFAM call rate?

• What is the typical number of users " waiting for server" at peak times and what size server do they require?

Are any of these potential bottlenecks keeping you and your users from exploiting the full power of your database?

Summary

SirMon is the only tool designed for Model 204 operations management. SirMon is fully compatible with all CCA-supported versions of Model 204, and is kept up to date by Sirius Software. SirMon's set of operations tools and performance tuning features is the professional choice for operations management, performance monitoring, and problem solving in Model 204.