Re: Release a database connection from pool
2013/9/10 Christopher Schultz > It can't: not all JDBC drivers use TCP/IP, so the only thing the DBCP > can do is call Connection.close and hope the driver does something > intelligent. It makes sense > > That's up to the database server. I can't imagine a db server that > would not know what to do under these circumstances. OK. Thanks Christopher - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Release a database connection from pool
-BEGIN PGP SIGNED MESSAGE- Hash: SHA256 Jose, On 9/9/13 2:56 PM, Jose María Zaragoza wrote: > Hello: > > I've got a simple question. I'm using Tomcat 6 & DBCP library ( bit > I've got the same question with Tomcat JDBC pool ) > > > My question is: > > when DBCP wants to release a database connection from the pool ( > for example , if it is idle for more than > minEvictableIdleTimeMillis ) > > does it just close the TCP socket connection ( FIN packet )? It can't: not all JDBC drivers use TCP/IP, so the only thing the DBCP can do is call Connection.close and hope the driver does something intelligent. > If it does, is it enough for remote database server knows that it > has to release its resources ? That's up to the database server. I can't imagine a db server that would not know what to do under these circumstances. > Or does it do anything more by using propietary driver's commands? > I asking me if ( some ) database servers need a special command to > finish a connection/session ? Servers need to be tolerant of clients disappearing without warning. Any sane database would rollback any in-progress transactions and, of course, release any server-side resources necessary to support that client. - -chris -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.14 (Darwin) Comment: GPGTools - http://gpgtools.org Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQIcBAEBCAAGBQJSLyDWAAoJEBzwKT+lPKRYbt0QAIwX+FltnxXCiYR39HqGHPop HUbFx36HykgODEhwWPaPUqKKs3+7TZO0bOSxGeXIyehN/zwZczswArSGKlWGvlVo pOWLpp5qgqycL0CgqGG0tnmz369PGNz3FdXHMiZNGIoEiDzhgcz8//6tDKVZoWYK 6m8YrzEirdbTtr+KteIQUVDop1wn1jPdYZ0Nz2GBRoaeYLvjs6kqtbtt64xks4zn 8Fyp5lvnZHtBcLFZAeOaMBx9KdU1QN+ihDKm/ngEi1iPe94VoQxMmi8nEg5T69Ql rToR7cIOexDbrzoOGTvMjs3LqWVcwD8wQYTh2xJ7SruvG2EMaJjPVswaCK49sTe2 G50EhuihctfJtlxqYP1leGeNYTBrGLSlNsUCKROYZ8POAuMg+pPJoD+geK0fCLIt ffiET0aLmwT5pGVdNcEmcNnDRAjTnErmc+CNP/p+KhBlwBf3/t1XyqFWRunzN24a Q97ycxrtueuMOnGxSDeZ7UfPXn644IKi3VEgiKXrlANz51qAXn9eR21sl7KnJLMR QUZ+dKJWKdMta6rimkQ25zdiyXzlZrds9S39oK4vMhDIUo85BTApU08a1SV8R76t p41u7M3SxaJzmJELH+/svbb9sSb6NlyzqdYO6QuclBRyqXHGulOQfvGMeX5e7Xig y9R/xtkAIttxDFTvI6cp =BAiZ -END PGP SIGNATURE- - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Release a database connection from pool
On Sep 9, 2013, at 4:10 PM, Jose María Zaragoza wrote: > 2013/9/9 Daniel Mikusa : >> On Sep 9, 2013, at 2:56 PM, Jose María Zaragoza wrote: >>> >>> Or does it do anything more by using propietary driver's commands? I >>> asking me if ( some ) database servers need a special command to >>> finish a connection/session ? >> >> Not sure what you mean here. Can you elaborate? > > Thanks. > > I would like to know if closing the underlying TCP connection is > enough to notify to database server that it has to release any > resource reserved for that connection. > > Or some database servers have got a propietary way ( a protocol , i > mean ) to finish connections ( known by propietary driver ) > Of course, finally, the TCP connection is closed but I wonder if there > is any message interchange between driver and database server to > finish the connection. Hard to say. I suppose you could setup Wireshark and monitor the traffic between your Tomcat instance and your database to see what happens. That might give you some idea as to what' going on. > Really my question is if an intermediate firewall finishes the > connection , the database server realizes that it must to release its > resources Again, hard to say because you're asking about the behavior of the database. You'd be better off asking the mailing list for the DB (if it's OSS) or support (if it's proprietary). Dan > > I don't know if I explained better ... > > > Regards > > - > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Release a database connection from pool
2013/9/9 Daniel Mikusa : > On Sep 9, 2013, at 2:56 PM, Jose María Zaragoza wrote: >> >> Or does it do anything more by using propietary driver's commands? I >> asking me if ( some ) database servers need a special command to >> finish a connection/session ? > > Not sure what you mean here. Can you elaborate? Thanks. I would like to know if closing the underlying TCP connection is enough to notify to database server that it has to release any resource reserved for that connection. Or some database servers have got a propietary way ( a protocol , i mean ) to finish connections ( known by propietary driver ) Of course, finally, the TCP connection is closed but I wonder if there is any message interchange between driver and database server to finish the connection. Really my question is if an intermediate firewall finishes the connection , the database server realizes that it must to release its resources I don't know if I explained better ... Regards - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Re: Release a database connection from pool
On Sep 9, 2013, at 2:56 PM, Jose María Zaragoza wrote: > Hello: > > I've got a simple question. > I'm using Tomcat 6 & DBCP library ( bit I've got the same question > with Tomcat JDBC pool ) > > > My question is: > > when DBCP wants to release a database connection from the pool ( for > example , if it is idle for more than minEvictableIdleTimeMillis ) > > does it just close the TCP socket connection ( FIN packet )? > If it does, is it enough for remote database server knows that it has > to release its resources ? I can't speak for DBCP, but Tomcat's jdbc-pool will call Connection.close() when appropriate. I would guess that DBCP does the same thing. > > Or does it do anything more by using propietary driver's commands? I > asking me if ( some ) database servers need a special command to > finish a connection/session ? Not sure what you mean here. Can you elaborate? Dan > > > Thanks and regards > > - > To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org > For additional commands, e-mail: users-h...@tomcat.apache.org > - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org
Release a database connection from pool
Hello: I've got a simple question. I'm using Tomcat 6 & DBCP library ( bit I've got the same question with Tomcat JDBC pool ) My question is: when DBCP wants to release a database connection from the pool ( for example , if it is idle for more than minEvictableIdleTimeMillis ) does it just close the TCP socket connection ( FIN packet )? If it does, is it enough for remote database server knows that it has to release its resources ? Or does it do anything more by using propietary driver's commands? I asking me if ( some ) database servers need a special command to finish a connection/session ? Thanks and regards - To unsubscribe, e-mail: users-unsubscr...@tomcat.apache.org For additional commands, e-mail: users-h...@tomcat.apache.org