7.2 Relationship between number of logs to keep and performance
The number of logs to keep is the number of generations to be saved as the execution result of a jobnet. You can set a number of logs to keep for a root jobnet. When you set a number of logs to keep, you can view the execution result of the set generations (times) in the Daily Schedule window or Monthly Schedule window, or by using the ajsshow command. You can set a value from 1 to 99 as the number of logs to keep, which can be expanded to 999 in the environment settings of the JP1/AJS3 - Manager scheduler service.
However, as the number of logs to keep increases, the number of records calculated by number-of-logs-to-keep x number-of-registered-units also increases, in proportion to the scale of the jobnet. This has a significant effect on operations that access the database. For this reason, carefully consider the effect on system performance when you determine a value to set as the number of logs to keep. This setting affects the following main functionality (processing):
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Startup of a scheduler service
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Cancellation of registration for execution
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Display of the Monthly Schedule window and Daily Schedule window of JP1/AJS3 - View
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Display of the Dashboard screen and Monthly Schedule screen of JP1/AJS3 - Web Console
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Creation of generations when a start condition is satisfied
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Execution of ajsshow and other commands
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Job execution
For the above processing, there is a tendency for the number of records and the processing time to increase in proportion to each other. From an unloaded state, it will take about one or two minutes to cancel the registration for processing of 1,000,000 records, and 8 to 10 minutes to display the Monthly Schedule window (although this might vary depending on the system performance). This processing will take even longer if the system is experiencing heavy loads such as high CPU utilization or frequent disk access. In contrast, it will take only a few seconds to cancel the registration for processing of 100,000 records, and one or two minutes to display the Monthly Schedule window.
If you use the recommended configuration of two or three jobnet hierarchy levels with each jobnet containing about 50 to 80 units, the processing speed will be acceptable for operation even when the number of logs to keep is set to the maximum of 999.
If you want to increase the number of logs to keep, try to design jobnets on a small scale. If you want to create a large-scale jobnet, decrease the number of logs to keep. Keep this balance in mind when you design a jobnet.
Under most circumstances, design jobnets on a small scale and set a small number of logs to keep, bearing in mind that processing might be performed in parallel. For example, a job might be running during cancellation of registration while its status is being monitored in the Monthly Schedule window.
The processing time for cancellation of registration mentioned above is the time that applies when the registration cancellation mode is asynchronous, as described in 6.1.7 Changing the mode in which unregistration or generation management deletes the generations of a jobnet in the JP1/Automatic Job Management System 3 Configuration Guide (for Windows), or 15.1.7 Changing the mode in which unregistration or generation management deletes the generations of a jobnet in the JP1/Automatic Job Management System 3 Configuration Guide (for UNIX). If the registration cancellation mode is synchronous, the processing will take dozens of minutes.
In new installations, the method of deleting generations is set to asynchronous (yes) by default. In the case of an upgrade installation, however, the method might have been set to synchronous (no) at some point. We recommend that you check the value of the BACKGROUNDLEAVE environment setting parameter, and ensure that it specifies asynchronous mode.
If you have upgraded from version 8 or earlier, in the case of a jobnet for which a start condition is set, monitored generations (generations that enter Now monitoring status) and execution generations (generations produced when a start condition is satisfied) are managed separately by default. For this reason, setting a large number of logs to keep will have an even greater effect for such jobnets. In this case, the number of records is: number-of-registered-units x number-of-logs-to-keep x number-of-times-start-condition-is-satisfied-per-schedule. For a jobnet with a start condition, we recommend that you keep fewer than 10 logs and use the ajsshow command to save the execution results as needed. For details about the ajsshow command, see ajsshow in 3. Commands Used for Normal Operations in the manual JP1/Automatic Job Management System 3 Command Reference. For points to note when increasing the number of logs to keep for jobnets for which start conditions are set after upgrading from version 8 or earlier, see 4.2.3(4) Notes applying when JP1/AJS3 has been upgraded from JP1 Version 8 or an earlier version of JP1/AJS2 in the manual JP1/Automatic Job Management System 3 Overview.