B.2 Remote host monitoring history output timing

This subsection explains the times at which HA Monitor outputs remote host monitoring history.

When HA Monitor on the local host starts monitoring between hosts

HA Monitor issues a message reporting that collection of monitoring history has started.
When HA Monitor has received an alive message from the remote host after the amount of time set for collection of host monitoring history

A message indicating occurrence of a slowdown is issued.
When the remote host is terminated abnormally due to a failure on the remote host

A message indicating that collection of monitoring history has ended is issued. If the cause of the failure is a slowdown, a message indicating occurrence of the slowdown is also issued.
When servers on the local host or the remote host have terminated and no other server is available for hot standby processing

A message indicating that collection of monitoring history has ended is issued.
When HA Monitor on the local host or the remote host has terminated

A message indicating that collection of monitoring history has ended is issued.

The following figure shows an example of remote host monitoring history output timing.

Figure B‒2: Remote host monitoring history output timing

The following explains the remote host status at the times indicated by numbers in the figure:

The standby server starts.

HA Monitor on the local host starts monitoring operations between hosts because the hosts are now ready for hot standby processing and starts collection of monitoring history (ID: 0101).
A slowdown occurs that lasts longer than the amount of time set for collection of host monitoring history.
The slowdown status is resolved before the host failure monitoring time is reached.

HA Monitor on the local host collects monitoring history (ID: 0103) when it has received an alive message.
The active server is terminated.

Because hot standby processing can no longer be performed, HA Monitor on the local host terminates monitoring of operations between hosts and collects monitoring history (ID: 0102).