connection refused

Hi, I’m new with the use of knime server and webportal, and I’m stucked with running the examples.
For example, trying the WebPortal Data Mining (Basic) workflow on Knime Webportal, it doesn’t show any input form and only shows “Workflow is currently executing…”

The related knime.log file part
is attached. It seams a connection problem, but I don’t understand how can I fix it.

Thanks in advance.
Claudiaknime.doc (170.5 KB)

This looks like a network setup issue. The workflow running inside the executor is trying to report its status back to the server on IP address This should the the host’s IP address but it seems it’s not reachable from itself. This indicates that the network setup on your server is not correct or there is a (local) firewall preventing access.

You are right… after removing the firewall (and waiting over the night!) the workflows are running. But I’m required to set the firewall again. What are the ports that knime uses? I would leave them open.

Hi there!

KNIME Server and its clients communicate by either HTTP, or HTTPS. Default ports are 8080, and 8443. These ports can be changed in the range: 1024-49151.

Hope this is what you were searching for.


The server uses random ports to communicate with the executor. Since they both run on the same computer there is no need to open any (additional) external ports. The firewall simply needs to allow arbitrary local connections.