DB Connector 5:207 - ERROR: Execute failed: IO Error: Unknown host specified.

[takbb]

Hi @kotlapullareddy , so the error message changes when you use IP Address instead of server name.

(Partial success in troubleshooting comes when, as a result of your actions, the error message changes! )

OK, so it doesn’t solve the problem but this tells me that first off the KNIME server is not able to resolve the server name to an IP Address and this suggests that there is a configuration difference between running manually and running as a scheduled task.

Unfortunately I don’t use KNIME Server so I don’t know how the environment is configured for running scheduled tasks, or indeed whether it runs as a different account/user.

Back to your error messages though:
IO Error: Unknown host specified normally means that the Oracle connector is unable to locate the server that the database is running on

The Network Adapter could not establish the connection would typically mean that it found the server, but that something is blocking the connection or else the wrong database service name or port number has been specified.

Given that (I assume) the node configuration is not different between when you run it manually and when you run it as a scheduled task, my starting guess here is that some firewall software, or other network configuration differs between the two different executions.

The fact that the IP address, but not the server name finds the host machine would suggest that for starters, DNS is not configured/running when executing on the server as a scheduled task.

It’s as if the manual and scheduled executions are occurring on two different environments/machines where one has access to the database through the network, and the other is being blocked. But if, as you suggest, both executions (manual and scheduled) are taking place on the server, then there must be different network configuration/permissions for the two execution environments.

I think this may need the additional input of somebody with experience of how KNIME server is configured for executing scheduled workflows.

Taking a look at the following discussion on Oracle connectivity:
DB Connector Oracle:

@takbb

Incorrect Port Number or Incorrect host name along with invalid format - such as using “:” instead of “/” before database name
ERROR DB Connector 8:10 Execute failed: IO Error: The Network Adapter could not establish the connection

In that thread, I noted that the error you are now getting could also result from the database driver configuration using an invalid format. Is it possible that the driver configuration differs between running manually, and running as a scheduled job?

Is there anything in this post that may be able to assist? :

KNIME Server Oracle DB Connection

Hi @KKERROXXX Have you added the information about the profile location in the executor’s knime.ini? Like we explain on the client-side setup part of the documentation. Are you using linux/windows server? If linux, and you have the server and executor installed as services, you can do systemctl restart knime-server and then systemctl restart knime-executor to restart the services. If on windows, you can just go to the services view and restart the Apache service and executor service. Best wis…