LoadBalancer pointing SGTM service returns 502:backend_connection_closed_before_data_sent_to_client

Google Cloud Compute Infrastructure
1

Hello, I have a lot of log entries with 502 status code and message backend_connection_closed_before_data_sent_to_client

I have set the timeout and connection draining timeout on LB to 60s.

What do I need to provide additionally?

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2

Hi,

This is seen when the backend unexpectedly closed its connection to the load balancer before the response was proxied to the client. Some details on this error in this table:

https://cloud.google.com/load-balancing/docs/https/https-logging-monitoring#failure-messages

What is the backend? Do you know why the backend might be closing the connection without sending data?

Alex

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3

We are running SGTM from Google in our backend, they are in the Kubernetes cluster

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4

If you make requests directly to the backend, do you see some requests not return? is there anything logged?

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5

I can’t send direct request to the backend as it is blocked for a traffic not from LB. What I can do is port-forward one of the pods and send traffic there, seems like all good here

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