Exporter should start even when database is down

[technoronin]

Since starting Postgres is independent of starting monitoring, it would be very helpful if postgres_exporter reported the database as down rather than refusing to start.

[wrouesnel]

This one was a deliberate decision I might need to revisit - the idea was that at deployment time you probably start the exporter while your database is up, and if it's not then you'd like to have your deployment scripts break and alert you to the issue and/or misconfiguration preventing contacting the database.

[technoronin]

That's a reasonable decision for environments where the Postgres server is considered ephemeral. Unfortunately, the environment I am dealing with has Postgres running on bare metal with databases in the 10s of TBs and a process that involves upgrading servers rather than building from scratch, so it is quite possible to have machines designated as database servers with no currently running database. Or, when our DBA is experimenting, database servers going up and down a lot.

[wrouesnel]

No that's totally fair and I'll change the behaviour. It'll need to include a few additional metrics I think so the exporter can yell more clearly if it's not working (and why).

[wimoMisterX]

+1