TNSListener & JDBC

Don't know if anybody else has come across this, but the TNSListener can behave alarmingly when a connection attempt is made from a Java program using the JDBC drivers.

What happens is this:
If the user attempting to connect enters invalid login criteria the Java program appears to generate hundreds, (sometimes more than 200) connection attempts, all on different port numbers within a couple of seconds. The cumulative effect of this over a day is to eventually crash the TNSListener with the following message

TNS-12500: TNS:listener failed to start a dedicated server process  TNS-12540: TNS:internal limit restriction exceeded   TNS-12560: TNS:protocol adapter error
   TNS-00510: Internal limit restriction exceeded     32-bit Windows Error: 8: Exec format error

and we have to restart the Listener. This is extremely frustrating for our users - if only they could get their user names and passwords right!

What I don't understand is that when a user logs in with a VALID user name and password we only get the one connection you would expect.

I have checked the code in the Java program and I am satisfied that it is closing down the connection correctly, both when it manages to login to the database and when it doesn't.

Now the question is this:
We have one NT Server on which 8.1.7 was installed from scratch where the behaviour still occurs but is more managable, ie we only get four or five connection attempts for invalid logins, result: TNSListener doesn't crash.

The machine where this is occuring is likewise an NT Server, but was upgraded from 8.1.6 to 8.1.7 & the behaviour continues.

Both machines are running the same version of the same Java program, and both are running the JDK 1.2.2. They both use the Classes12.zip provided by Oracle.

So, is this a configuration issue for the Listener? Can I tell it to only limit the number of ports it uses to, say, 5 instead of 200-ish? Or is it something else? Please help!

Thanks in advance
Tarik Received on Wed May 01 2002 - 03:46:19 CDT