6.1.5 Processing performed when failover occurs on ITSLM - Manager
When failover occurs on ITSLM - Manager, the service performance information that has been written onto the shared disk by ITSLM - Manager on the active server up to that point is inherited by ITSLM - Manager on the standby server. The standby server resumes business operations on the basis of the inherited information. However, monitored-service detection processing is not resumed.
The following figure shows the processing that is performed when failover occurs on ITSLM - Manager.
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When failover occurs, the service performance is inherited, but the icons indicating error and warning statuses displayed on the window are not inherited. When the service is restarted after failover processing, the service performance is re-analyzed and the appropriate icons are displayed based on the analysis results.
The following subsections explain the failover processing flows depending on the timing of the failover.
- Organization of this subsection
(1) While neither monitoring nor detection of monitored services is being performed
When failover occurs on ITSLM - Manager while neither monitoring nor detection of monitored services is being performed, only the connection to ITSLM - UR is restored after ITSLM - Manager is started on the standby server. Neither monitoring nor detection processing is started.
(2) While monitored services are being monitored
When failover occurs on ITSLM - Manager while monitored services are being monitored, the monitoring status is restored to what it was immediately before the failure, on the basis of the service performance information in the database on the shared disk after ITSLM - Manager has started on the standby server.
The following figure shows the processing flow when failover occurs on ITSLM - Manager while monitored services are being monitored.
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The following explains the processing flow shown in the figure, where the numbers correspond to the numbers in the figure:
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The cluster software (active server) starts ITSLM - Manager (active server). The cluster software (active server) also starts periodic monitoring of server status.
Note that you must start ITSLM - UR manually. For details about how to start ITSLM - UR manually, see 2.1.2 Starting ITSLM - UR.
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ITSLM - Manager (active server) starts monitoring the monitored services.
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Because a failure has occurred on ITSLM - Manager (active server), the Windows services stop.
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All Windows services for ITSLM - Manager that have been registered into ITSLM - Manager (active server) are stopped by the cluster software (active server), after which failover processing starts.
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The cluster software (standby server) starts ITSLM - Manager (standby server). The cluster software (standby server) also starts periodic monitoring of server status.
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The cluster software (standby server) restarts monitoring of the monitored services by ITSLM - Manager (standby server). The service performance collected by ITSLM - UR is sent to ITSLM - Manager (standby server).
(3) While detection of monitored services is being performed
When failover occurs on ITSLM - Manager while detection of monitored services is being performed, the detection processing is canceled.
The following figure shows the processing flow when failover occurs on ITSLM - Manager while monitored services are being detected.
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The following explains the processing flow shown in the figure, where the numbers correspond to the numbers in the figure:
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The cluster software (active server) starts ITSLM - Manager (active server). The cluster software (active server) also starts periodic monitoring of server status.
Note that you must start ITSLM - UR manually. For details about how to start ITSLM - UR manually, see 2.1.2 Starting ITSLM - UR.
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ITSLM - Manager (active server) starts detecting monitored services.
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Because a failure has occurred on ITSLM - Manager (active server), the Windows services stop.
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All Windows services for ITSLM - Manager that have been registered into ITSLM - Manager (active server) are stopped by the cluster software (active server), after which failover processing starts.
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The cluster software (standby server) starts ITSLM - Manager (standby server). The cluster software (standby server) also starts periodic monitoring of server status.
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The cluster software (standby server) stops detection of monitored services by ITSLM - Manager (standby server). It also sends a notification to ITSLM - UR indicating that detection of monitored services is stopped.