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Port blocked?

Occasional Visitor

Port blocked?

Hello, for few months, we are having an issue on 3node Itanium cluster (B.11.31). The main problem is that occasionally (aprox. once a week) one of our Sybase backupservers hangs up frozen because of communication fail (reporting Network error = 32). The backup server is on the same node as adaptive server where it tries to connect.
Up to this point it looks like question for Sybase support, but we managed to narrow it down a bit:
When we try 10x manually connect to our database running on hostname.port we 9x succeed and 1x fail. The error message reports, that there is no database on hostname.port (unable to connect endpoints). It looks like something is occasionally blocking the port (but the next blocked port is usually other than before) Would you please advice what to examine and investigate?

Thank you

btw network guys said it's not their issue because it does not go outside the box (it happens both when you are connecting from host1.port1 to host1.port2 and also from host2.portX to host1.port2), cluster people rejected it because it happens "inside" cluster resource, sys admins sent me to Sybase support and Sybase support identified it as network problem...

Steven E. Protter
Exalted Contributor

Re: Port blocked?


netstat -an | grep

Do this on the box in question.

Step 1 is to figure out if the service is listening on the node. Sybase IMO does not have enough data to identify the problem and we need to know if it is the network configuration or some other cause.

Steven E Protter
Owner of ISN Corporation
Occasional Visitor

Re: Port blocked?

Yes, it's definitely listening.

For example, when I script 100x consequent login attempts to our 15 databases/replication servers, random 10 of them fails.

When I checked netstat -a, I found the dbs instance listening on the ports as expected.