Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
We run a 4 node setup where we have a hot standby and a cascading replication setup like:
where A is the master.
We want to monitor the delays at various points seperately, i.e. A->B should have a low delta, whereas A->C can be longer, whereas C->D should also be low delta.
We couldn't get our desired monitoring with any of the existing checks so we had to add one.
This lets a pginstance be monitored based on receiving and sending WAL, so we can monitor the delay between our cascading replication servers. We've also added the ability to limit based on being in the same network as the cluster that's being checked from which is useful for checking only local replicas if you have a hub-and-spoke-style replication strategy.