KNIME Server Connector - No session cookie available

KNIME Server
1

Hi,

I updated the KNIME Analytics Platform from version 4.6.5 to 4.7.2 .KNIME Server version is 4.16.3.

I am using the KNIME Server Connector node to connect to the server but after the update I get the following error:

ERROR KNIME Server Connector 5:3846 Execute failed: Error occurred during login: No session cookie available.

Is this a bug?

Best

A.

2

Hello,

So we have one desktop (unknown OS) running KNIME AP 4.7.2, connecting to one server host (unknown OS) running KNIME Server (KS) 4.16.3.
AP workflow has KNIME Server Connector, and when executed, produces:
Execute failed: Error occurred during login: No session cookie available.

  • is the KNIME Executor (KE) also on the same host as the KNIME server?
  • Are there any other hosts involved, such as firewalls, VPN tunnels, proxies, or load balancers?
  • is the KNIME Executor also upgraded to 4.7.2?
  • Do you have AP logs (knime-workspace/.metadata/knime/knime.log)?
  • Do you have Server/Executor logs for the same timeframe?

Note that if you would like to provide logs and there exists a possibility for them to contain proprietary or confidental data in them, please do not post them here, but, rather, reach out to us directly at support@knime.com for further assistance.

Thank you,
Nickolaus

3

Hallo @NDekay ,

thanks for your reply.

  • is the KNIME Executor (KE) also on the same host as the KNIME server?
    → Yes, the KE runs on the same host. We just updated the server (KNIME Server Ubuntu 20 Server LTS). The KNIME AP runs on Windows 10.

  • Are there any other hosts involved, such as firewalls, VPN tunnels, proxies, or load balancers?
    → We have but the same settings as before and with the old KNIME AP version 6.5, the connector still works

  • is the KNIME Executor also upgraded to 4.7.2?
    → Yes, the Executor is version 4.7.2.

  • Do you have AP logs (knime-workspace/.metadata/knime/knime.log)?

  • Do you have Server/Executor logs for the same timeframe?

→ In the end I did not need the KNIME Server Connector node with the new Call Workflow (Table Based) node included (I had to update my workflow).

I still got the error message but for me the problem is solved (Not sure if the KNIME Server Connectore node is still needed with the new configuration options in the Call workflow nodes. Interstingly, the Mountpoint Connector node works to connect to the server. I did not know of this node before.)

Many thanks.

Best

A.

4

Hello,

I am glad that you were able to find a resolution through adjusting your workflow.
If you experience any further issues, please let us know.

Thank you,
Nickolaus

5

Hi, i think i have the same issue with a KE 4.7.2 on the local mashine everything seems to work fine. I switched now from “Knime Server Connector” to “Knime Mountpoint Connector” which is in my case anyhow the better way, but it seems the “Knime Server Connector” has a problem in 4.7.2.

6

Hi @KarstenS,

thanks for confirming. I’m glad you have a better workaround (is it still a workaround if it is better? :thinking:), but in case anyone else gets stuck here without a workaround.
I’d guess into the blue that this may be related to http:// access to the KNIME Server. With Chrome I’ve had a similar issue that it refused to work with certain headers and cookies via http after an update.

A solution may therefore be to switch to https:// access to the KNIME Server (or even mount it as https in the KNIME Explorer view).

Kind regards
Marvin

7

Oh my fault, i used already
https://MyCoolKnimeServer:8443
http is not allowed on our server.
So i get this error with the https-address.

You should be able to reproduce this, if you open a job on knime server with only this node and execute it.

8

Hi @KarstenS

thanks for following up. I can reproduce this behavior. This may indeed be a bug; I’ll further investigate and keep you posted.

EDIT: Upon further investigation, it seems that the URL wasn’t quite right, see my reply below. This is also the URL you should get when you choose the KNIME Server URL via the “Select…” button in the Connector node configuration.

However, the error message is very confusing. I’ll pass this feedback on.

9

A quick solution may be to specify the KNIME Server with the same URL you see when connecting to the WebPortal.
Likely that is https://MyCoolKnimeServer:8443/knime (note the /knime) in your case.

Kind regards
Marvin

10

@marvin_kickuth
Thanks for the reply, unfortunatelly i get still the same error.

There are messages for workflow “KNIME_Server_Connector 2023-06-27 08.20.03”
KNIME Server Connector 3:1 - ERROR: Execute failed: Error occurred during login: No session cookie available.

11

Hi Karsten,

sorry to hear the fix doesn’t do. These seem to be two separate issues; I was able to reproduce the issue with /knime in the URL, interestingly only on some servers.

We’re investigating internally. I’ll keep the thread posted.

Kind regards
Marvin

12

Hi again,

it looks like we have identified the culprit. The issue is quite technical, but should only come up if embedded data apps are allowed to be embedded in iframes.

KNIME Analytics Platform clients and Executors in version 4.7.2 and newer will fail to connect via KNIME Server Connector while the CookieProcessor entry is set in <apache-tomcat>/conf/Catalina/localhost/knime.xml.

As a knimeadmin / server administrator, a workaround would be to remove the CookieProcessor entry and restart KNIME Server. However, this will also disable support for embedding Data Apps in iframes.

We will provide a proper solution in the next KNIME Server version (4.16.5). I’m very sorry for the inconvenience this may cause.

Kind regards
Marvin

EDIT: adjusted affected version from 4.7.3 to 4.7.2.

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13

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