> JSON seems the most sensible format for the string. Inventing a new one > doesn't make sense. Most important for me is the ability to > programmatically manipulate/edit the config string, which would be harder > with a new custom format.
Do we need to keep the value consistent across all the servers in the flock? If not, is the behavior halfway sane upon failover?
Mostly, yes. Which means it doesn't change much, so config data is OK.
If we need the DBA to keep the value in sync manually, that's going to be a recipe for trouble. Which is going to bite particularly hard during those stressing moments when disaster strikes and things have to be done in emergency mode.
Manual config itself is the recipe for trouble, not this particular setting. There are already many other settings that need to be the same on all nodes for example. Nothing here changes that. This is just an enhancement of the current technology.
For the future, a richer mechanism for defining nodes and their associated metadata is needed for logical replication and clustering. That is not what is being discussed here though, nor should we begin!
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Simon Riggs http://www.2ndQuadrant.com/ PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services