Обсуждение: Connections dropped randomly
I find that if I reuse a jdbc connection to perform a number of update queries (e.g. 1000), the connection keeps getting dropped after a random number of iterations. This occurs in all sorts of queries throughout my application. Any idea what might be causing this? I'm not doing anything out-of-the-ordinary, and it happens on both prepared statements and regular statements. I had this problem in postgres 7.3, and it's still there after upgrading to 7.4.4 & pg74.215.jdbc2.jar. Thanks, -Mike
Without seeing your code, or your setup, it's hard to say. But given that exactly the same thing is done by lots of other people without the problem, I'd be hard pressed to say it's a bug in the driver, or postgresql. Dave On Thu, 2004-09-02 at 19:09, Mike Bridge wrote: > I find that if I reuse a jdbc connection to perform a number of > update queries (e.g. 1000), the connection keeps getting dropped > after a random number of iterations. > > This occurs in all sorts of queries throughout my application. Any > idea what might be causing this? I'm not doing anything > out-of-the-ordinary, and it happens on both prepared statements > and regular statements. > > I had this problem in postgres 7.3, and it's still there after > upgrading to 7.4.4 & pg74.215.jdbc2.jar. > > Thanks, > > -Mike > > ---------------------------(end of broadcast)--------------------------- > TIP 8: explain analyze is your friend -- Dave Cramer 519 939 0336 ICQ # 14675561 www.postgresintl.com
Mike Bridge wrote: > I find that if I reuse a jdbc connection to perform a number of > update queries (e.g. 1000), the connection keeps getting dropped > after a random number of iterations. > > This occurs in all sorts of queries throughout my application. Any > idea what might be causing this? I'm not doing anything > out-of-the-ordinary, and it happens on both prepared statements > and regular statements. The usual cause of lost connections is a stateful firewall (or NAT, etc) between the client and server. If a connection stays idle for too long, the firewall may consider that connection dead and reject subsequent traffic on it. The driver doesn't discover this until the next time the connection is used. If that's not it, at a minimum we'd need to see a stack trace of the error you get to diagnose this any further. -O
I think I may have finally figured out the source of this problem. I'm getting a connection from a JDO connection manager (but not using JDO here), and it reaps these connections with no activity after 10 seconds by default. Under load, some of the updates can take this long, so I've upped the timeout, and this seems to have taken care of the problem so far. Thanks, -Mike ----- Original Message ----- From: "Dave Cramer" <pg@fastcrypt.com> To: "Mike Bridge" <mike@bridgecanada.com> Cc: <pgsql-jdbc@postgresql.org> Sent: Thursday, September 02, 2004 5:27 PM Subject: Re: [JDBC] Connections dropped randomly > Without seeing your code, or your setup, it's hard to say. > > But given that exactly the same thing is done by lots of other people > without the problem, I'd be hard pressed to say it's a bug in the > driver, or postgresql. > > Dave > On Thu, 2004-09-02 at 19:09, Mike Bridge wrote: > > I find that if I reuse a jdbc connection to perform a number of > > update queries (e.g. 1000), the connection keeps getting dropped > > after a random number of iterations. > > > > This occurs in all sorts of queries throughout my application. Any > > idea what might be causing this? I'm not doing anything > > out-of-the-ordinary, and it happens on both prepared statements > > and regular statements. > > > > I had this problem in postgres 7.3, and it's still there after > > upgrading to 7.4.4 & pg74.215.jdbc2.jar. > > > > Thanks, > > > > -Mike > > > > ---------------------------(end of broadcast)--------------------------- > > TIP 8: explain analyze is your friend > -- > Dave Cramer > 519 939 0336 > ICQ # 14675561 > www.postgresintl.com > > > ---------------------------(end of broadcast)--------------------------- > TIP 6: Have you searched our list archives? > > http://archives.postgresql.org >