From: Tom Lane <tgl@sss.pgh.pa.us>
To: Arjun Ranade <ranade@nodalexchange.com>
cc: Alvaro Aguayo Garcia-Rada <aaguayo@opensysperu.com>,
        pgsql-admin <pgsql-admin@postgresql.org>
Subject: Re: PG10 - Out of shared memory / invalid memory alloc request size
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Comments: In-reply-to Arjun Ranade <ranade@nodalexchange.com>
	message dated "Tue, 14 Nov 2017 15:07:18 -0500"
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Date: Tue, 14 Nov 2017 15:15:29 -0500
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Arjun Ranade <ranade@nodalexchange.com> writes:
> We will try that.  I am wondering why we need to worry about this in pg10
> whereas we had no issues with shared memory in 9.4

What it looks like to me is something is miscomputing a memory request
size and asking for some silly amount of memory.  I think you're dealing
with a software bug, not inadequate configuration.

> Anecdotally it seems that these errors are happening when
> powa_take_snapshot() (Postgres workload analyzer) is running as well but
> I can't confirm that.

The first theory that comes to mind is that powa_take_snapshot() requires
some updates for PG10.  I do not know what that function is or where you
got it from, but if there's any C code involved, you need to discuss this
with its developer(s).

			regards, tom lane


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