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TNS-12547: TNS:lost contact error after Windows2003 SP1 upgrade [message #231943] Wed, 18 April 2007 21:49 Go to next message
Messages: 35
Registered: April 2007
Location: Malaysia
Hi Guys,

I got the above error intermittently when trying connect to the database. This error occured after we upgraded to the new Win2003 SP1. No changes from application and database during period only the SP1 upgrade.From the listener log, I saw this error appear: 'TNS-12502: TNS:listener received no CONNECT_DATA from client'

After consult with Microsoft and Oracle engineer, they said this is something related to the system resources/very low on memory buffer space.

Our boot ini file have /3GB and /PAE, Microsoft advise to remove the /3GB from the boot to give 2GB to the kernel, but this will limit 2GB to user process(including Oracle). I'm afraid this might cause CPU/memory issue to the oracle later.

After we rollback the SP1, everything work fine again. You guys have any idea on the error?

My total SGA size is around 1.5GB and PGA is around 150MB, if we sum up the SGA, PGA and the user connection, the size might grow to around 1.7 to 1.8GB. Will this cause low buffer in the memory?

Re: TNS-12547: TNS:lost contact error after Windows2003 SP1 upgrade [message #232003 is a reply to message #231943] Thu, 19 April 2007 01:17 Go to previous message
Messages: 961
Registered: August 2006
Location: Stockholm/Sweden
Senior Member

Have you verified the cause of the ORA-error.

TNS-12502 TNS:listener received no CONNECT_DATA from client
Cause: No CONNECT_DATA was passed to the listener.
Action: Check that the service name resolved from TNSNAMES.ORA has the CONNECT_DATA component of the connect descriptor.

So, the first step is to check your TNSNAMES.ORA file that the clients are using and verify that it looks something like this:


Seems also that this can occur when a port scanning app is running and scanning the port/address of the listener.

I guess that you have checked metalink since you have been in contact with Oracle.

[Updated on: Thu, 19 April 2007 01:23]

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