The notes in this subsection apply to using the delay monitoring facility.

• You use a status information collection command (hdestate or hdsstate) to view the delay period. This means that Datareplicator must be running in order to view the delay period.
• The delay monitoring facility is applicable only when extraction, transmission, and import processes are running. The facility does not monitor a delay period for a process that is stopped.
• The delay monitoring facility supports only Japan Standard Time (JST-9).
• If data is imported from a PDMII SAM file, the facility monitors the import delay period beginning at the time of execution of the hdssamqin command.
• Do not use the delay monitoring facility in an environment in which some transactions require a large differential between the update time of the last updating SQL statement and the time of commit processing. Even if the extraction delay period has not resulted in an exceeded delay (status in which the operand's threshold is exceeded), the transmission delay period or import delay period might result in an exceeded delay.
• If there is a mismatch between the times at the source and target systems, the facility cannot provide accurate delay period monitoring.

To illustrate this note about the delay monitoring facility, Figures 3-38 and 3-39 show examples in which 1 minute is specified as the threshold for the import delay period.

Figure 3-38 When the target system's time is behind

A warning message is output whenever it takes 1 minute or more for import processing to be completed after update information is stored in the system log file. In the case of the environment shown in Figure 3-38, the target system's system time is 2 minutes behind the system time at the source system. Only if it takes 3 minutes or more until import processing is completed will a warning message be output. In this case, you can adjust the target system's time to match the source system's time, in order to obtain the expected processing based on the set threshold. To change the time, you must terminate the related products that are running. If you are backdating the target system's time, you must start the related products after they have caught up with the time to be set.

Figure 3-39 When the target system's time is ahead

As in the environment shown in Figure 3-38, a warning message is output whenever it takes 1 minute or more until import processing is completed after update information is stored in the system log file. In this example, the target system's system time is 2 minutes ahead of the system time at the source system, so the warning message is output even before import processing is completed. In this case, you can prevent output of the warning message by adjusting the target system's time to match the time at the source system.

Supplement:

To avoid cases such as those shown in these examples, we recommend that when there is a time difference between the source and target systems, you make the necessary adjustments to the system times in advance. If you will not be adjusting the system times in cases such as these, specify a threshold that takes into account the time difference between the source and target systems.