[pgpool-general: 7484] Consensus failover issues?

Martin Goodson kaemaril at googlemail.com
Wed Apr 7 21:38:05 JST 2021


Hello.

Got a bit of a weird one here, wondering if anyone can offer any insight 
in case I'm missing the blazingly obvious (which is quite possible)?

I have three pgpool nodes - pgpool 4.0.4* running in watchdog mode - 
monitoring set of PostgreSQL 10.5* database in streaming replication mode.

A colleague built these, cribbing off a pgpool I built quite some time 
ago that is running fine (and sailed through all testing including 
failover of the database, pgpool failover, and so forth, so I'm 
satisfied that one is OK)

He shutdown the primary database this morning for a test, expecting 
pgpool to failover to the standby database.

It didn't.

It seems the primary pgpool node detected the failover, and is waiting 
on consensus from the two standby nodes.

And it is waiting.

And waiting.

And waiting.

It says it's slow in getting consensus.

And keeps waiting ...

I see no indication in the standby logs that they've decided that there 
needs to be a failover. They're reporting numerous failures to connect 
to the database, but other than that they appear quite unperturbed.

I'm a bit puzzled.

As far as I can see, the parameters for 'failover by consensus' are in 
place:

failover_when_quorum_exists is on
failover_require_consensus is on
enable_multiple_failover_requests_from_node is off

I'm going to try some tests this afternoon with some enhanced logging to 
see what I get, but I just thought I'd check here just in case ...

Are there any known issues with this feature we might be running into?

I know it's a long shot, and hopefully I should have some more info and 
logging later, but just thought I'd quickly ask in case somebody can go 
'Oh yes, we had that too, you forgot to do [X]' or some such obvious 
things :)

TIA.

Regards,

Martin.

* I know, I know. My org isn't keen on keeping up to date on latest 
versions as recommended by the community, more of the 'If it ain't broke 
don't fix it' way of thinking :(
-- 
Martin Goodson

Whatever you've got planned, forget it. I'm the Doctor.
I'm 904 years old. I'm from the planet Gallifrey in the
constellation of Kasterborous. I am The Oncoming Storm,
the Bringer of Darkness and you are ... basically just a
rabbit, aren't you? OK, carry on, just a general ...
warning.


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