Calling Workflow Service does not call Workflow in Analytic Platform

KNIME Analytics Platform
1

Hy Community!

I have a workflow, which uses “Call Workflow Service” and “Call Workflw (Row Based)” multible times with a local Workflow on an ubuntu installation with KNIME Analytics Platform 5.1.2. The Workflows are called and I do get the expected results. But the called Workflows are not executed in the Plattform. Thus the “Workflow Service Input” in the called Workflow shows the error “No data objject set from calling workflow (via external API)”. Debuging and development of sub-Workflows is impossible.

Anyone who can help?

Thanks
Matthias

2

Hi Matthias,
I am not sure I understand. You say you get the expected result, but at the same time there is an error? Is the result you get maybe the default output of the called workflow’s output node?
Kind regards,
Alexander

3

I get the result (if the call is successfull) at the end of the “call Workflow …” Node. But in the GUI the called Workflow is not running. Therefor I have no data input at the “Container Input” Node. In the GUI the Container Input Node is red and shows the error “No data object set from calling workflow (via external API)”. Thus I can not run or develop nodes which rely on external data via “Call Workflow” API

thank you for any help
Matthias

4

Hi,
To understand better, I have recorded a quick video. You are saying the way I show it there it is not working for you, but this is what you expect?
Kind regards,
Alexander

5

Yes, thats true. Workflow “4: Calee” does stays “red” and untouched. Saved Workflows do not change to the status edit (with the smal Dot on the right side). It worked for me with KNIME 4.7.7

thank you for your support
Matthias

6

Hi Matthias,
Can you send me your KNIME Log as a private message so I can check it for error messages? You find it if you switch to the old UI view and go to View → Open KNIME Log.
Kind regards,
Alexander

7

How do I switch to old UI?

8

Hi Matthias,
For that you click the “i” button in the top-right corner, then scroll down a little. There is a button to switch to the classic interface.
Kind regards,
Alexander

9

Hy!
log is comming any minute. In the Classic UI it works fine. My Callee Workflow is called and executed in the GUI.
Thanks for your help
Matthias

10

KNIME-log-Matthias.log (26.7 KB)
Sorry I did not find a way to send it as private message.
I had to remove some parts in the log.
Matthias

11

Hi Matthias,
Thanks a lot for the log file. I think it is very helpful, but I am going to have to take it to our developers to confirm my suspicion. When you look at the error:

2023-11-10 13:10:52,717 : WARN  : ModalContext :  : WorkflowOutputNodeModel : Workflow Service Output : 4:212 : Creation of hard links not supported, will copy files instead (and suppress further warnings)
java.nio.file.FileSystemException: /tmp/output-resource12741419360797659151.portobject -> /home/wem/knime-workspace-V5/xxx/Workflow Service Output (#212)/internal/output-resource.table: Invalid cross-device link

It looks like KNIME sees that it should not create links and should copy files instead, but then it still tries to create a link and that fails. Maybe there is a bug and the check is simply ignored for some reason. I will get back to you once I hear something from our devs!
Kind regards,
Alexander

1 Like
12

Hi Matthias,
I think my suspicion was wrong, but I have another hunch. When you use Call Workflow Service, you need to use the Workflow Service Input and Output nodes, not the Container Input. Can you try that?
Kind regards,
Alexander

13

Hi Alexander,
I use both: “Call Workflow Service” with “Workflow Service Input” and “Call Workflow (Row Based)” with “Container Input”.

Both work when I switch to the “Classic user Interface”, but are not called in the KNIME Analytic Platform Graphical User Interface with the new User Interface on our Ubuntu 22.04 LTS.

Best regards
Matthias

14

Hi Matthias,
That’s interesting. I explicitly tested both interfaces on my machine to make sure this is not the case. But I am not on Linux, maybe that plays a role. I will make sure to ask a colleague to reproduce the issue and will get back to you when I hear back!
Kind regards,
Alexander

1 Like
15

Hy Alexander,
I prepared a Log File where I first execut
Mountpoint Connector 3:297
and than
Call Workflow Service 3:308
which calls the Workflow “FFG-BP-Beiratssitzung-Data”
for both User Interfaces: First Classic UI and then New User Interface

maybe this helps.
Thank you in advance
Matthias
KNIME-log-Matthias(Classic and New).log (21.1 KB)

1 Like
16

Hi Matthias,
I have not yet been able to reproduce the issue and in the log you shared both executions in modern and classic UI seem to yield the same output.
Could you share two minimal workflows (caller and callee) that exhibit this behaviour on your machine? I recommend just using some dummy data, but if you do not want to share it publicly, I can also send you a private message to which you can respond with the workflows.
Kind regards,
Alexander

1 Like
17

Hy Alexander!
Here is the Workflow and a quick Video (I had to rename it from .webm to mp4 for the upload).
Thank’s
Matthias


Test Call Workflow.knar (75.5 KB)

18

Hi,
Thanks, I could reproduce the issue now. It does, however, seem to happen inconsistently. Sometimes it works. In the workflow group you sent the Test-Call-Workflow is empty and I noticed that when I reproduce your steps after having recreated the nodes, when I switch to the classic UI, the nodes in the workflow vanish. Very weird. But now that I can show it internally, I am sure we can fix it. Thanks for reporting it! I will update here when I know more.
Alexander

1 Like
19

Hi Matthias,
Our developers have confirmed it as a bug and are working on it under ticket number NXT-2179.
Kind regards,
Alexander

2 Likes