Re: JDBC client causes TNS-12502 on server's listener

Enkidu Utnapishtim <utnapishtim43NOSPAM_at_hotmail.com> wrote in message news:<3D373F55.5020605_at_hotmail.com>...
> Cindy,
> Thanks for the quick reply Cindy. I checked with the developers and they
> assure me that they're using Oracle's thin driver.
>
> We have just two main Java aps: our WebLogic app that checks connections
> every 5 mintues (in case database loses a connection) and a "check" app
> that attempts to connect every 10 minutes (verifies URL is accessible).
> I can see entries for both of these in the log. But between are all the
> TNS-12502 errors.
> Roger
> C. Ferguson wrote:
> > Well,
> > what driver are you using to connect to the oracle db? Try using
> > Oracle's thin driver (type4). See if that makes a difference.
> >
> > hth,
> > Cindy
> >
> > Enkidu Utnapishtim wrote:
> >
> >> I am trying to research why a JDBC client (WebLogic java app) keeps
> >> generating a "TNS-12502: TNS:listener received no CONNECT_DATA from
> >> client" in my server's listener.log file. The message appears every
> >> minute or so (making my listener.log grow way too fast).
> >>
> >> I checked MetaLink and did a Google search (web and newsgroups).
> >>
> >> Practically every response says to check the tnsnames.ora on the
> >> client for a valid CONNECT_DATA entry. Well now, that's mighty fine
> >> advice if the client is anything other than a JDBC (or ODBC)
> >> connection. As far as I can determine, JDBC completely and totally
> >> ignores tnsnames.ora anyhow. That's why you have to put connect
> >> strings like "host:port:sid" in many of Oracle's Java wizards (eg,
> >> Portal Config Assistant) instead of the alias name from tnsnames.ora
> >> ... so it can construct a JDBC compliant connect string.
> >>
> >> So, my question is, where do I look (if not in the client's
> >> tnsnames.ora) for the problem?
> >>
> >> Thanks,
> >> Roger Crowley - LearningFramework - DBA
> >>
> >

JDBC thin driver does not require Oracle client installation and middleware. It is a pure java driver which sits on top of the TCP stack. That is why you need fully qualified TCP ONLY connect string as, jdbc:oracle:thin:@<HOST>:<PORT>:<SID>.

JDBC oci driver, on the other hand, needs Oracle client and middleware installation because it uses native API's to connect and uses tnsnames.ora to verify connect string as, jdbc:oracle:oci7|8:@<Service name from tnsnames.ora file>

HTH
//Rauf Sarwar Received on Thu Jul 18 2002 - 23:27:19 CDT