Re: "multiple backends attempting to wait for pincount 1" - Mailing list pgsql-hackers

From Kevin Grittner
Subject Re: "multiple backends attempting to wait for pincount 1"
Date
Msg-id 1387048438.2773502.1423868716121.JavaMail.yahoo@mail.yahoo.com
Whole thread Raw
In response to Re: "multiple backends attempting to wait for pincount 1"  (Andres Freund <andres@2ndquadrant.com>)
Responses Re: "multiple backends attempting to wait for pincount 1"
List pgsql-hackers
Andres Freund <andres@2ndquadrant.com> wrote:

> How did you get to that recipe?

I have been working on some patches to allow vacuum to function in
the face of long-held snapshots.  (I'm struggling to get them into
presentable shape for the upcoming CF.)  I was devising the most
diabolical cases I could to try to break my patched code and
started seeing this error.  I was panicked that I had introduced
the bug, but on comparing to the master branch I found I was able
to cause it there, too.  So I saw this a couple days before the
report on list, and had some cases that *sometimes* caused the
error.  I tweaked until it seemed to be pretty reliable, and then
used that for the bisect.

I still consider you to be the uncontested champion of diabolical 
test cases, but I'm happy to have hit upon one that was useful 
here.  ;-)

--
Kevin Grittner
EDB: http://www.enterprisedb.com
The Enterprise PostgreSQL Company



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