Re: DBCP woes (running out of cursors).

2009-10-28 Thread Elli Albek
Hi, >From what I can remember, which has been a long time ago, requests are being handled by servlets after the shutdown process has started and the pool was closed. I would imagine that this is a violation of the spec as well, but I am not sure. You would imagine that JNDI resources should be avai

Re: DBCP woes (running out of cursors).

2009-10-28 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Elli, On 10/28/2009 12:21 AM, Elli Albek wrote: > In terms of listeners, I saw that Tomcat executes requests while in > the closing process. That's a problem. What kind of listener are you using? >> My understanding was that: >> >> 1. Tomcat does no

Re: DBCP woes (running out of cursors).

2009-10-27 Thread Elli Albek
Thanks for your replies. I agree that Tomcat should be responsible for all objects that are configured in Tomcat, and the web app should be responsible for objects that are created by the webapp. Currently it does not happen properly in tomcat. This is not related to DBCP code, it is all Tomcat cod

Re: DBCP woes (running out of cursors).

2009-10-27 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Elli, On 10/26/2009 10:59 PM, Elli Albek wrote: > To disable caching in DBCP, use configuration option: > poolPreparedStatements=false Note that this is the default. Presumably, if you don't know if your prepared statements are being cached, then the

Re: DBCP woes (running out of cursors).

2009-10-27 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Elli, On 10/26/2009 9:01 PM, Elli Albek wrote: > 2. If your JDBC driver supports caching of prepared statements and > metadata, do it in the driver and disable this in DBCP. IMO DBCP > does a poor job at best in caching. We use mysql and its JDBC dri

Re: DBCP woes (running out of cursors).

2009-10-27 Thread Bill Davidson
Elli Albek wrote: >2. If your JDBC driver supports caching of prepared statements and >metadata, do it in the driver and disable this in DBCP. IMO DBCP does >a poor job at best in caching. We use mysql and its JDBC driver is >doing an excellent job. It didn't occur to me that that was available.

Re: DBCP woes (running out of cursors).

2009-10-26 Thread Elli Albek
Hi, More information about tomcat shutdown and object swapping probably belongs in the development list. It is quite a bit of work to extend DBCP and write extensions to tomcat, and at the end of the day most of those problems I would consider as bugs. DBCP specifically cannot be easily extended, w

RE: DBCP woes (running out of cursors).

2009-10-26 Thread Martin Gainty
mg>good work > From: e...@sustainlane.com > To: users@tomcat.apache.org > > Hi, > I did not follow this thread form the beginning, but I can provide a > few tips about using connection pools in tomcat. > 1. DBCP has quite a few problems in the area of scalability. We have > our own modified vers

Re: DBCP woes (running out of cursors).

2009-10-26 Thread Elli Albek
Hi, I did not follow this thread form the beginning, but I can provide a few tips about using connection pools in tomcat. 1. DBCP has quite a few problems in the area of scalability. We have our own modified version of the source that makes it more concurrent, and I believe some of those changes we

Re: DBCP woes (running out of cursors).

2009-10-26 Thread Mark Thomas
Bill Davidson wrote: > Christopher Schultz wrote: >>When you've played with it for a bit, tell us how things turned out. > > It's looking like optimal is caching about 40 PreparedStatement objects. > However, I should qualify that noting that it's with our application and > specifically with our l

Re: DBCP woes (running out of cursors).

2009-10-26 Thread Bill Davidson
Christopher Schultz wrote: >When you've played with it for a bit, tell us how things turned out. It's looking like optimal is caching about 40 PreparedStatement objects. However, I should qualify that noting that it's with our application and specifically with our little pummeling benchmark, whic

Re: DBCP woes (running out of cursors).

2009-10-23 Thread Bill Davidson
I already got a response to the ehancement request. Apparently the documentation will be changed to this: Make sure your connection has some resources left for the other statements. Pooling PreparedStatements may keep their cursors open in the database, causing a connection to run out

Re: DBCP woes (running out of cursors).

2009-10-22 Thread Bill Davidson
Christopher Schultz wrote: >I see you've cross-posted to commons-user. That's good, but you probably >want to file an actually bug report / enhancement request for the >documentation. Filed. Key: DBCP-301 - To unsubscribe, e-

Re: DBCP woes (running out of cursors).

2009-10-19 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/19/2009 3:14 PM, Bill Davidson wrote: > Christopher Schultz wrote: >> I'm curious about the usefulness of caching prepared statements in >> general, though. What is the default maxOpenPreparedStatements setting >> and what did you set it t

Re: DBCP woes (running out of cursors).

2009-10-19 Thread Bill Davidson
Christopher Schultz wrote: I'm curious about the usefulness of caching prepared statements in general, though. What is the default maxOpenPreparedStatements setting and what did you set it to in order to get it to work out well for you? The default is unlimited, which is the problem. I've b

Re: DBCP woes (running out of cursors).

2009-10-19 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/16/2009 5:36 PM, Bill Davidson wrote: > Bill Davidson wrote: >>Could maxOpenPreparedStatements possibly fix this? > > Apparently it does. Glad to get the bottom of this problem, though I'm not entirely sure where it leaves you. > The DB

Re: DBCP woes (running out of cursors).

2009-10-16 Thread Bill Davidson
Bill Davidson wrote: >Could maxOpenPreparedStatements possibly fix this? Apparently it does. The DBCP config docs need a better warning on poolPreparedStatements: "*NOTE* - Make sure your connection has some resources left for the other statements." just doesn't quite cut it. Something more

Re: DBCP woes (running out of cursors).

2009-10-16 Thread Bill Davidson
Just thinking about this some more So apparently, when I was using poolPreparedStatements="true", and I did conn.prepareStatement(SomeSQLString), I was getting back a Statement object created by DBCP to be pooled. When I called close() on that statement, it did not really close(), which was

Re: DBCP woes (running out of cursors).

2009-10-16 Thread Bill Davidson
Christopher Schultz wrote: >Uh, oh. Are you doing something like this: Possibly. I didn't write that code. >If you're doing that, then you're probably making a big mistake. Are you >storing connections in sessions or anything like that? Yuk. For certain transactional operations, I think it is.

Re: DBCP woes (running out of cursors).

2009-10-16 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, (I've decided to stop cross-posting to commons-user. If you want to forward come of my comments, you are welcome to do so). On 10/15/2009 5:07 PM, Bill Davidson wrote: > I'm a little confused about auto-commit. I don't want my transactions > a

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Bill Davidson
Christopher Schultz wrote: >Probably not. DBCP calls setAutoCommit(true) by default in order to >reset the connection as it goes back into the pool. Any pending >transaction is committed (!) when that happens, so there shouldn't be >any in-progress transactions lingering around. > >If you set auto

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Hassan Schroeder
On Thu, Oct 15, 2009 at 1:46 PM, Christopher Schultz wrote: > You could also ask on some Java-oriented Oracle forums. Oracle has a user community called Mix -- https://mix.oracle.com/ -- where you could post your issue (requires registration but otherwise free). /* It's JRuby on Rails but not,

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/15/2009 2:24 PM, Bill Davidson wrote: > That does make me wonder though if there are Connection's getting sent > back to the pool that had a pending transaction without a commit/rollback > and if that could be making any cursors on that co

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/15/2009 2:15 PM, Bill Davidson wrote: > Christopher Schultz wrote: >>Is it possible that your server just doesn't want to allocate 245 * 4 >>cursors, and that you are just hitting that barrier? > > cursor != connection Right... but presu

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Bill Davidson
Martin Gainty wrote: >are you running as a Transaction? In some cases, but a lot of these lingering cursors are on very simple queries, with no insert/update/delete involved. As I said before, I'm finding lingering cursors on things as simple as "SELECT * FROM some_table WHERE id = ?". That doe

Re: DBCP woes (running out of cursors).

2009-10-15 Thread Bill Davidson
Christopher Schultz wrote: >Is it possible that your server just doesn't want to allocate 245 * 4 >cursors, and that you are just hitting that barrier? cursor != connection Oracle is set up to allow up to 300 cursors per session (connection). I could up that limit, but it probably won't fix the

RE: DBCP woes (running out of cursors).

2009-10-14 Thread Martin Gainty
les email peuvent facilement être sujets à la manipulation, nous ne pouvons accepter aucune responsabilité pour le contenu fourni. > Date: Wed, 14 Oct 2009 21:22:35 -0400 > From: ch...@christopherschultz.net > To: users@tomcat.apache.org > CC: u...@commons.apache.org > Subject: Re: D

Re: DBCP woes (running out of cursors).

2009-10-14 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/14/2009 5:05 PM, Bill Davidson wrote: > Usually, we don't need that many [connections], but sometimes, we get hit > really hard > with a lot of traffic and do need that many. BTW, this is load balanced > across 4 servers that can each do

Re: DBCP woes (running out of cursors).

2009-10-14 Thread Bill Davidson
Christopher Schultz wrote: >On 10/14/2009 2:17 PM, Bill Davidson wrote: >>Redhat 5.2 Server >Wow. Maybe I should have said RHEL 5.2. 5.3 would be the current version, so it's actually not that old. RedHat's starting over with the numbers does get confusing. >This config looks fine, though the

Re: DBCP woes (running out of cursors).

2009-10-14 Thread Christopher Schultz
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Bill, On 10/14/2009 2:17 PM, Bill Davidson wrote: > Redhat 5.2 Server Wow. > I've been trying to convert an old J2EE application to use DBCP connection > pools from an old custom connection pool class (not a DataSource > interface). I've moved a co

DBCP woes (running out of cursors).

2009-10-14 Thread Bill Davidson
Redhat 5.2 Server Java: Sun JDK 1.6.0_16 (64-bit) Tomcat 6.0.20 (and whichever version of DBCP that includes) Oracle 10g (10.2.0.3) JDBC: ojdbc14.jar I've been trying to convert an old J2EE application to use DBCP connection pools from an old custom connection pool class (not a DataSource interf