Received: from malur.postgresql.org ([217.196.149.56]) by arkaria.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VbVnS-0003fL-AJ for pgsql-hackers@arkaria.postgresql.org; Wed, 30 Oct 2013 13:26:54 +0000 Received: from localhost ([127.0.0.1] helo=postgresql.org) by malur.postgresql.org with smtp (Exim 4.80) (envelope-from ) id 1VbVnQ-0004EV-Tk for pgsql-hackers@arkaria.postgresql.org; Wed, 30 Oct 2013 13:26:52 +0000 Received: from makus.postgresql.org ([2001:4800:7903:4::125]) by malur.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VbVnP-0004EI-7f for pgsql-hackers@postgresql.org; Wed, 30 Oct 2013 13:26:51 +0000 Received: from sss.pgh.pa.us ([66.207.139.130]) by makus.postgresql.org with esmtp (Exim 4.80) (envelope-from ) id 1VbVnJ-000224-3v for pgsql-hackers@postgresql.org; Wed, 30 Oct 2013 13:26:50 +0000 Received: from sss1.sss.pgh.pa.us (localhost [127.0.0.1]) by sss.pgh.pa.us (8.14.4/8.14.4) with ESMTP id r9UDQguV027890; Wed, 30 Oct 2013 09:26:42 -0400 From: Tom Lane To: Robert Haas cc: Andrew Dunstan , "pgsql-hackers@postgresql.org" Subject: Re: Something fishy happening on frogmouth In-reply-to: References: <6557.1383073940@sss.pgh.pa.us> Comments: In-reply-to Robert Haas message dated "Wed, 30 Oct 2013 08:45:03 -0400" Date: Wed, 30 Oct 2013 09:26:42 -0400 Message-ID: <27889.1383139602@sss.pgh.pa.us> X-Pg-Spam-Score: -2.4 (--) List-Archive: List-Help: List-ID: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: X-Mailing-List: pgsql-hackers Precedence: bulk Sender: pgsql-hackers-owner@postgresql.org Robert Haas writes: > If I'm reading this correctly, the last three runs on frogmouth have > all failed, and all of them have failed with a complaint about, > specifically, Global/PostgreSQL.851401618. Now, that really shouldn't > be happening, because the code to choose that number looks like this: > dsm_control_handle = random(); Isn't this complaining about the main shm segment, not a DSM extension? Also, why is the error "not enough space", rather than something about a collision? And if this is the explanation, why didn't the previous runs probing for allowable shmem size fail? BTW, regardless of the specific properties of random(), surely you ought to have code in there that would cope with a name collision. regards, tom lane -- Sent via pgsql-hackers mailing list (pgsql-hackers@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-hackers