Re: Deadlock in multiple CIC. - Mailing list pgsql-hackers

From Alvaro Herrera
Subject Re: Deadlock in multiple CIC.
Date
Msg-id 20180418153626.didla63talgczupk@alvherre.pgsql
Whole thread Raw
In response to Re: Deadlock in multiple CIC.  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: Deadlock in multiple CIC.  (Tom Lane <tgl@sss.pgh.pa.us>)
List pgsql-hackers
Tom Lane wrote:

> Anyway, at this point I'm going to give up on the debug logging, revert
> 9.4 to its prior state, and then see if the transaction-restart patch
> makes the problem go away.

Agreed, thanks.

> >> (A couple of the other isolation tests do fail reliably under this
> >> scenario; is it worth hardening them?)
> 
> > Yes, I think it's worth making them pass somehow -- see commits
> > f18795e7b74c, a0eae1a2eeb6.
> 
> Will look into that too.  I'm not sure that adding extra expected
> outputs is sane, though --- might be best to just force the intended
> isolation level within those tests.

As I recall (not much, admittedly) that was one of the options we
considered in the old commit, but since the other isolation levels
behaved differently we ageed that it was worth adding coverage for them.
I don't know which ones are failing now; maybe forcing a specific
isolation level is sufficient.

Clearly we should have done something to make sure these tests were run
periodically with different isolation levels.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services


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