KNIME case swtich cannot fully execute in loop

Dear KNIME team,

As title, I have workflfow which have loop(include switch node).

In workflow, I face the problem that when i change data, the swtich (in port 1 node) are not fully execute all node and turn into next iteration without any error message.

And when I execute step by step iteration, i found that swtich node became idle. need manual execute(cannot auto run).

I wonder know why cause this problem. (Use KNIME 4.5.2 version)

Thanks in advance.



Hi Willy,

Can you bring a example from your flow to here?

Maybe you need to add between the loop start and the switch case input a rule engine to validate row-by-row a condition for set a port direction.

First, with rule engine, you can set a value into a column as integer and then you set it on a variable.

With this variable, you can control the switch ports as you wish.


I used the switch ends to merge de data, but you can change this flow as I told you.

With loop end, it’ll pass all rows and you can control the loop variables and some permition too…

Using variables loops ends, you can control how the loop will validate the conditions.

This the flow attached.

loop_switch_rules.knwf (19.3 KB)

I hope this help you!




Sorry due to company policy, I can’t provide workflow.

I am very appreciated that you provide reference for me. It is very helpful.

Because my flow in each port data output format is different. I didn’t combine switch end in loop. I adjust output format let my output data can fit switch end node. Finally it works!

Thanks again.




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