Warning logged: DefaultSockJsService: Unknown transport type for ...jsonp

[nitram509]

Hi,

I'm about to set up Zeebe in AWS and see many of such WARN messages in the STDOUT log of Zeebe Simple Monitor.
Obviously, I expect zero warn messages but have to admit I can't observe wrong behavior.

I can't observe any issues in the web UI, but see 404 error messages in the browser's developer console and in the log text of Zeebe Simple Monitor.

Context:

• Zeebe Broker Cluster 1.0.1 (using Zeebe Cluster Helm Chart for Kubernetes v0.0.223)
• Zeebe Simple Monitor 2.0.0 (using Zeebe Monitor Helm Chart for Kubernetes v0.0.1)
• There's a dedicated Hazelcast Cluster running
• All services run in AWS EKS
• The Simple Monitor has no ingress defined, and we use another Nginx service as a reverse proxy that handles authentication.

Request Headers (URL and Cookie values modified)

GET /notifications/775/lgz0tdjt/jsonp?c=_jp.al2crhu HTTP/1.1
Host: simple-monitor.example.com
Connection: keep-alive
sec-ch-ua: " Not;A Brand";v="99", "Google Chrome";v="91", "Chromium";v="91"
DNT: 1
sec-ch-ua-mobile: ?0
User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/91.0.4472.114 Safari/537.36
Accept: */*
Sec-Fetch-Site: same-origin
Sec-Fetch-Mode: no-cors
Sec-Fetch-Dest: script
Referer: https://simple-monitor.example.com/
Accept-Encoding: gzip, deflate, br
Accept-Language: en-GB,en-US;q=0.9,en;q=0.8,de;q=0.7
Cookie: dtCookie=foobar; _oauth2_proxy=foobar

Response Headers (no modification)

HTTP/1.1 404 Not Found
Date: Wed, 30 Jun 2021 13:07:25 GMT
Content-Length: 0
Connection: keep-alive
Server: nginx/1.19.3
Vary: Origin
Vary: Access-Control-Request-Method
Vary: Access-Control-Request-Headers

Log Message (no modification)

Jun 30 15:02:49 simple-monitor-deployment-5766c596db-nsqvr  2021-06-30 13:02:48.455  WARN 1 --- [io-8082-exec-11] o.s.w.s.s.t.h.DefaultSockJsService       : Unknown transport type for https://simple-monitor-service.services.svc.cluster.local/notifications/677/e3xgsrla/jsonp?c=_jp.abl1cnn

[saig0]

From the failure message, I would assume that it is related to the notifications that are sent from the backend to the frontend via websockets.

Do you see any notification on the process instance view if the instance changes (e.g. when an activity is completed)?

[nitram509]

I did not test all cases, yet.
I see one notification when I deployed a new workflow via "deploy" button.