[PERFORM] Tuning Postgres 9.1 on Windows
I'm trying to benchmark Postgres vs. several other databases on my workstation. My workstation is running 64 bit Windows 7. It has 12 gb of RAM and a W3550 @ 3 Ghz. I installed Postgres 9.1 using the windows installer. The data directory is on a 6Gb/s SATA SSD. My application is multithreaded and uses pooled connections via JDBC. It's got around 20 threads doing asynchronous transactions against the database. It's about 70% read/30% write. Transactions are very small. There are no long-running transactions. I start with an empty database and I only run about 5,000 business transactions in my benchmark. That results in 10,000 - 15,000 commits. When I first installed Postgres I did no tuning at all and was able to get around 40 commits per-second which is quite slow. I wanted to establish a top-end so I turned off synchronous commit and ran the same test and got the same performance of 40 commits per second. I turned on the large system cache option on Windows 7 and got the same results. There seems to be some resource issues that's limiting me to 40 commits per second but I can't imagine what it could be or how to detect it. I'm not necessarily looking for advice on how to increase performance, but I at least need to know how to find the bottleneck. -- Les Walker CONFIDENTIAL: This e-mail, including its contents and attachments, if any, are confidential. If you are not the named recipient please notify the sender and immediately delete it. You may not disseminate, distribute, or forward this e-mail message or disclose its contents to anybody else. Copyright and any other intellectual property rights in its contents are the sole property of Cantor Fitzgerald. E-mail transmission cannot be guaranteed to be secure or error-free. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. Although we routinely screen for viruses, addressees should check this e-mail and any attachments for viruses. We make no representation or warranty as to the absence of viruses in this e-mail or any attachments. Please note that to ensure regulatory compliance and for the protection of our customers and business, we may monitor and read e-mails sent to and from our server(s). For further important information, please see http://www.cantor.com/legal/statement
Re: [PERFORM] Tuning Postgres 9.1 on Windows
On 4/30/2012 8:49 AM, Walker, James Les wrote: I’m trying to benchmark Postgres vs. several other databases on my workstation. My workstation is running 64 bit Windows 7. It has 12 gb of RAM and a W3550 @ 3 Ghz. I installed Postgres 9.1 using the windows installer. The data directory is on a 6Gb/s SATA SSD. My application is multithreaded and uses pooled connections via JDBC. It’s got around 20 threads doing asynchronous transactions against the database. It’s about 70% read/30% write. Transactions are very small. There are no long-running transactions. I start with an empty database and I only run about 5,000 business transactions in my benchmark. That results in 10,000 – 15,000 commits. When I first installed Postgres I did no tuning at all and was able to get around 40 commits per-second which is quite slow. I wanted to establish a top-end so I turned off synchronous commit and ran the same test and got the same performance of 40 commits per second. I turned on the “large system cache” option on Windows 7 and got the same results. There seems to be some resource issues that’s limiting me to 40 commits per second but I can’t imagine what it could be or how to detect it. I’m not necessarily looking for advice on how to increase performance, but I at least need to know how to find the bottleneck. -- Les Walker One thing I'd look at is your hardware and determine if you are CPU bound or IO bound. I use Linux so don't know how you'd do that on windows. Have you checked your sql statements with explain analyze? I don't know anything about config file settings on windows, but on Linux its really important. google could probably help you there. Knowing if you are CPU bound or IO bound, and if you have any bad plans, will tell you what config file changes to make. -Andy -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Tuning Postgres 9.1 on Windows
On Mon, Apr 30, 2012 at 8:49 AM, Walker, James Les jawal...@cantor.com wrote: I’m trying to benchmark Postgres vs. several other databases on my workstation. My workstation is running 64 bit Windows 7. It has 12 gb of RAM and a W3550 @ 3 Ghz. I installed Postgres 9.1 using the windows installer. The data directory is on a 6Gb/s SATA SSD. My application is multithreaded and uses pooled connections via JDBC. It’s got around 20 threads doing asynchronous transactions against the database. It’s about 70% read/30% write. Transactions are very small. There are no long-running transactions. I start with an empty database and I only run about 5,000 business transactions in my benchmark. That results in 10,000 – 15,000 commits. When I first installed Postgres I did no tuning at all and was able to get around 40 commits per-second which is quite slow. I wanted to establish a top-end so I turned off synchronous commit and ran the same test and got the same performance of 40 commits per second. I turned on the “large system cache” option on Windows 7 and got the same results. There seems to be some resource issues that’s limiting me to 40 commits per second but I can’t imagine what it could be or how to detect it. I’m not necessarily looking for advice on how to increase performance, but I at least need to know how to find the bottleneck. It's almost certainly coming from postgres being anal about making sure the data is syncing all the way back to the ssd through all the buffers. Although ssd are quite fast, if you run them this way they are no better than hard drives. Trying turning off fsync in postgrsql.conf to be sure. If you're still seeing poor performance, try posting and explain analyze of the queries you think might be slowing you down. Also, which ssd? merlin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Tuning Postgres 9.1 on Windows
Merlin Moncure wrote on 30.04.2012 23:43: Trying turning off fsync in postgrsql.conf to be sure. This is a dangerous advise. Turning off fsync can potentially corrupt the database in case of a system failure (e.g. power outage). -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
Re: [PERFORM] Tuning Postgres 9.1 on Windows
On Mon, Apr 30, 2012 at 5:00 PM, Thomas Kellerer spam_ea...@gmx.net wrote: Merlin Moncure wrote on 30.04.2012 23:43: Trying turning off fsync in postgrsql.conf to be sure. This is a dangerous advise. Turning off fsync can potentially corrupt the database in case of a system failure (e.g. power outage). sure. that said, we're just trying to figure out why he's getting around 40tps. since he's only benchmarking test data it's perfectly ok to do that. merlin -- Sent via pgsql-performance mailing list (pgsql-performance@postgresql.org) To make changes to your subscription: http://www.postgresql.org/mailpref/pgsql-performance
