Very Computer

Hi,

All apologies if this is not the right group but... :)

We get this error spontaniously when our application (Java) is busy writing
data to a SQL Server 2000 database. The application runs on the same machine
and connects using Microsofts JdbcOdbc driver.

Its a multi threaded app where one thread obtains a resultset and hands out
each row to a 'worker' thread (there are 4 worker threads). The worker
threads do not attempt to close the connection. At various stages the main
thread just closes the connection becuase some underlying factor decided to
close it. We would like to know what that 'factor' is... :)

Can someone tell me what influences an SQL connection? How it decides to
close based on certain criteria... Can it be because the system time changes
(trying to keep in sync with a domain controller's time (w32time))?

Specifics:
Machine with 4 CPU's, MS W2K, SQL 2000, Microsoft ODBC driver (installed
with Java VM with Win2K). On a nework with an NT 4 Primary domain controller
(already updated to use w32time instead of timeserv).

Regards,
Eben Esterhuyse
Mosaic Software

Eben,

Quote:> Can someone tell me what influences an SQL connection? How it decides to
> close based on certain criteria...

AFAIK, this is solely done based on the underlying network protocol. SQL Server does not try to
determine this itself.

--
Tibor Karaszi, SQL Server MVP
Archive at: http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sql...

Yep, I would have to agree. We used to have these all the time on our "old
network" where the network was designed very poorly, the firewall doing the
SQL proxying was very underpowered, etc. We moved to a new building and had
our network group design the network "properly", got a nice firewall for
proxying and have very little hops between our web servers and SQL servers
and we never see these any more.

--

Ross Nornes
DBA Services Manager
James Tower
http://www.JamesTower.Com

Quote:> Eben,

> > Can someone tell me what influences an SQL connection? How it decides to
> > close based on certain criteria...

> AFAIK, this is solely done based on the underlying network protocol. SQL

Server does not try to

Quote:> determine this itself.

> --
> Tibor Karaszi, SQL Server MVP
> Archive at:

http://groups.google.com/groups?oi=djq&as_ugroup=microsoft.public.sql...

Quote:> > Hi,

> > All apologies if this is not the right group but... :)

> > We get this error spontaniously when our application (Java) is busy
writing
> > data to a SQL Server 2000 database. The application runs on the same
machine
> > and connects using Microsofts JdbcOdbc driver.

> > Its a multi threaded app where one thread obtains a resultset and hands
out
> > each row to a 'worker' thread (there are 4 worker threads). The worker
> > threads do not attempt to close the connection. At various stages the
main
> > thread just closes the connection becuase some underlying factor decided
to
> > close it. We would like to know what that 'factor' is... :)

> > Can someone tell me what influences an SQL connection? How it decides to
> > close based on certain criteria... Can it be because the system time
changes
> > (trying to keep in sync with a domain controller's time (w32time))?

> > Specifics:
> > Machine with 4 CPU's, MS W2K, SQL 2000, Microsoft ODBC driver (installed
> > with Java VM with Win2K). On a nework with an NT 4 Primary domain
controller
> > (already updated to use w32time instead of timeserv).

> > Regards,
> > Eben Esterhuyse
> > Mosaic Software

Hi. You should use a type-4 JDBC driver to talk to MS SQLServer
If you have a multi-threaded client. The jdbc-odbc bridge is not
thread safe. However, the JDBC spec says that closing or re-executing
a statement will automatically invalidate any resultset previously
obtained from it. Closing a connection will automatically close any
statements from it, so the issue propagates down.