Re: dsa_allocate() faliure

On Wed, May 23, 2018 at 4:10 PM, Sand Stone <sand(dot)m(dot)stone(at)gmail(dot)com> wrote:
>>>dsa_allocate could not find 7 free pages
> I just this error message again on all of my worker nodes (I am using
> Citus 7.4 rel). The PG core is my own build of release_10_stable
> (10.4) out of GitHub on Ubuntu.

At which commit ID?

All of your worker nodes... so this happened at the same time or at
different times? I don't know much about Citus -- do you mean that
these were separate PostgreSQL clusters, and they were all running the
same query and they all crashed like this?

> What's the best way to debug this? I am running pre-production tests
> for the next few days, so I could gather info. if necessary (I cannot
> pinpoint a query to repro this yet, as we have 10K queries running
> concurrently).

Any chance of an EXPLAIN plan for the query that crashed like this?
Do you know if it's using multiple Gather[Merge] nodes and parallel
bitmap heap scans? Was it a regular backend process or a parallel
worker process (or a Citus worker process, if that is a thing?) that
raised the error?

--
Thomas Munro
http://www.enterprisedb.com