How it Works
This section describes how this feature works.
A site can be unavailable when it is undergoing maintenance level upgrade or experiencing a network issue. During this period, the site cannot manage the traffic that the client directs towards it. In such situations, you can isolate the site so that the traffic workload is switched from a primary site to a secondary site.
Configuring the PCF site isolation feature is a simplified process that involves issuing the commands from the PCF Ops Center console of the primary and secondary sites. The primary-secondary-primary switch includes the following:
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In the PCF Ops Center of the primary site, set the PCF registration status to UNDISCOVEREABLE. If the primary site is unavailable, the client automatically contacts the secondary site. Similarly, when the primary site comes online, the client attempts to connect to the primary site. No manual intervention is required to bring up the secondary site.
The primary and secondary sites are always synchronized, so the data integrity is maintained.
To determine whether all the traffic requests are switched successfully to the secondary site, review the traffic status on the Grafana dashboard. Also, verify that the primary site has not received any SBA inbound traffic.
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After the traffic is switched to a secondary site, you can bring down the primary site and take the required actions to upgrade or resolve the accessibility issues.
NoteIf you intend to isolate the site without disrupting the GR replication system, do not shut down the primary site.
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In the primary site, ensure that only the Ops Center-specific pods are running in the PCF product namespace. The rest of the pods must be terminated.
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After the planned activities are completed on the primary site, and it is ready to be brought back to a consistent state, bring up the primary site.
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Ensure that the sessions on the primary site are synchronized with the recent updates on the secondary site. You can verify the CDL changes and compare the CLD local session count on both the sites