Cluster endpoints were discovered once at add time and never re-read:
detectClusterMembership returned immediately for instances already marked
IsCluster, so when a cluster moved subnets Pulse kept dialing the dead
per-node addresses for failover and kept displaying them on Settings ->
Infrastructure, even though monitoring still worked through the main host
fallback. The manual /refresh-cluster endpoint exists but is not wired to
any UI control, so nothing ever corrected the stored addresses.
The 5-minute cluster re-check now also covers cluster instances: it
re-reads /cluster/status through the configured main host, and when a
node's address or the node set actually changed (volatile fields like
Online/LastSeen are ignored) it updates the stored endpoints, persists the
config, and rebuilds the failover client so polling moves to the new
addresses. User-managed fields (IP overrides, guest URLs, fingerprints)
are preserved by the existing discovery helpers, and fields the cluster
status API omits are inherited from the stored endpoint rather than
erased.
Refs #1493
rcourtman
82fdc6cfe2