Re: PostgreSQL on Cygwin - Mailing list pgsql-cygwin
From | Jason Tishler |
---|---|
Subject | Re: PostgreSQL on Cygwin |
Date | |
Msg-id | 20010704152932.A5837@dothill.com Whole thread Raw |
List | pgsql-cygwin |
Terry, On Tue, Jul 03, 2001 at 09:08:09PM +0000, Terry Carlin wrote: > I posted this message on the postgresql.ports.cygwin list and have not > heard anything from anybody. Tom Lane suggested that I contact you > directly with this problem. I monitor the pgsql-cygwin@postgresql.org mailing list very closely and I did not see any of your posts. To what mailing list does "postgresql.ports.cygwin" correspond? > Is there anything else I can provide to assist in solving this problem. > What I think I have found will block PostgreSQL from being used in real > world conditions under Cygwin. Can you reproduce this problem with any of the tests under src/test? Otherwise, I'm willing to download the Benchmark Factory 30 day trial to try to reproduce your environment. > Thanks > Terry Carlin > VP Q/A > Great Bridge, LLC. > terry@greatbridge.com > This is a copy of the posts > ------------------------------------------------------------------------ > ------------------------------------------------------------------------ > ----------------------------------------------------- > > After doing more investigation on this problem, I have discovered the > problem probably is not in PostgreSQL. > When I get to somewhere around 50,000 transactions with two users logged > on, the Win2K box will not allow > anymore processes to start. Bash complains about not being able to fork() > and I can't even start up the Win2k Notepad thru the start menu until I > kill the postgres backends. > I had the Task manager running and there was plenty of memory left. My WAG is that you have found a Cygwin resource leak -- my best guess is open handles. Since the activity of a benchmark application is by its very nature intensive and "long lived" as compared to someone typing away at bash, it would be much more likely for you to stumble over a resource leak than the typical Cygwin user. Try adding more columns (e.g, Handle Count) in Task Manager to determine whether or not my hypothesis is correct. Another option is to use Performance Monitor. If you do find a resource leak, then the next step is to isolate the part of Cygwin that is the culprit. But, ... > I don't think that the number of connections is the main factor. I have > logged in 10 psql concurrent sessions from other machines and have > executed some queries manually. I have not seen any problems doing this. > > > >>>>>>>>>>>>>>>>>> Original Message <<<<<<<<<<<<<<<<<< > > On 6/13/01, 4:05:08 PM, Terry Carlin wrote > regarding PostgreSQL error in pq_flush(): > > > > I am benchmarking PostgreSQL running on CYGWIN. I am using a tool called > > Benchmark Factory. It allows me to put > > a good load on a database. Benchmark Factory is using ODBC to connect to > > PostgreSQL. Are you sure that ODBC is not the culprit? I found the following thread: http://www.ca.postgresql.org/mhonarc/pgsql-bugs/2001-03/msg00062.html Maybe ODBC is still leaking other resources. > > I am running the A3ASP benchmark from 1 to 100 users. This is a query > > (read) only test. It measures how fast a database > > can retrieve random records out of a table. > > > Somewhere around 8 to 10 users, I start getting this message in the > > PostgreSQL log. > > > pq_flush: send() failed: No buffer space available; the socket cannot > > be connected > > > I am running PostgreSQL under Win2k Professional. > > I am using release Cygwin 1.3.2 and using PostgreSQL 7.2 from the Cygwin > > distro. I presume that you meant PostgreSQL 7.1.2 above. Also, you should try the latest snapshot: http://www.cygwin.com/snapshots/ Although it's a long shot, the problem may already be fixed. > > I don't see this problem with PostgreSQL on Linux or Sun and we connect > > 100 users during our tests. > > Our Benchmark Factory license is only for 100 users. > > > My goal is to run the same set of benchmarks that Great Bridge runs to > > test out every release of PostgreSQL that we support. > > This can give us an idea of the performance of PostgreSQL under Cygwin. I would be very interested in seeing the results when and if you get them. > > Has anyone seen this before? There is some speculation here that it > > might be a Microsoft restriction on the number of open sockets or > > something like that. There are MS limitations such as a small socket backlog count (on Windows 2000 Professional this value is 5). But, this would cause transient connection refused errors -- not prevent other apps such as Notepad from starting. Let me know how you make out. I will attempt to help you out as much as possible. Thanks, Jason -- Jason Tishler Director, Software Engineering Phone: 732.264.8770 x235 Dot Hill Systems Corp. Fax: 732.264.8798 82 Bethany Road, Suite 7 Email: Jason.Tishler@dothill.com Hazlet, NJ 07730 USA WWW: http://www.dothill.com
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