Error 502 - failed_to_pick_backend - Google Cloud Load Balancer

[Huy Nguyen]

Hi,

I've got an error 502 when I use google cloud balancer with CDN, the thing is, I am pretty sure I must have done something wrong setting up the load balancer because when I remove the load balancer, my website runs just fine. This is how I configure my load balancer

These are what I have tried so far:

• setting up https health check, my website was up for 30 mins, and it was down again. Should I use HTTP or HTTPS health check ? I have already set up https redirection.
• I have checked this link, they seem to have the same problem but it didn’t work for me.
• I have followed a tutorial from openlitespeed forum to set Keep-Alive Timeout (secs) = 60s in server admin panel and configure instance to accepts long-lived connections 
• I have added these 2 firewall rules following this google cloud links to allow google health check ip but still didn’t work: 
• https://cloud.google.com/load-balancing/docs/health-checks#fw-netlb
• https://cloud.google.com/load-balancing/docs/https/ext-http-lb-simple#firewall

Logs of load balancer show the error is failed_to_pick_backend

{

httpRequest: {…} 

insertId: "a9rb1qft79ox8" 

jsonPayload: {

@type: "type.googleapis.com/google.cloud.loadbalancing.type.LoadBalancerLogEntry" 

cacheId: "KUL-5a71ba6a" 

statusDetails: "failed_to_pick_backend" 

}

logName: "projects/naxa-website/logs/requests" 

receiveTimestamp: "2020-08-19T16:23:54.231047219Z" 

resource: {…} 

severity: "WARNING" 

spanId: "079bc54d9a438967" 

timestamp: "2020-08-19T16:23:53.138952Z" 

trace: "projects/naxa-website/traces/c31de897850dffb8da82e8ccebf39c63" 

}

I just started to learn GCP and my knowledge is really limited. It would be greatly appreciated if you show me step by step how to fix this problem. 

Best,

Huy

[Mohammad I (Cloud Platform Support)]

Hello Huy, 

The issue “Error 502 - failed_to_pick_backend - Google Cloud Load Balancer” that you have reported seems related to the Google Cloud Load Balancer not Google App Engine. 

I would recommend you to create a Cloud Load Balancing Issue under the “Networking” section by going here as the issue may be required to refer to the Cloud Load Balancing Engineering team to resolve it. Please select the private component as probably you will have to share project specific information, so that it is not visible to the public. One of the Google Cloud Platform Support Agents will assist you to resolve your issue.

Please note that Google Groups is only meant for general discussion related to Google Cloud Platform products which are not technical in nature, service status updates and release notes, and ranging from book recommendations to creative shortcuts.