Google cloud Backend service is unhealthy - 502 error

0
votes

I believe I have a pretty straight forward set up but I am receiving the dreaded "backend service is unhealthy" notification on my load balancer in google cloud. I will list out steps I have taken so far to provide as much info as possible as I know this could be many things.

  • I created a VM in compute engine hosting wordpress
  • I created an unmanaged instance group linked to that VM
  • I created a load balancer (HTTPS),
  • I created a HTTP backend service linking to my instance group
  • I created a health check, protocol HTTP, port 80, left everything else as default
  • I created a new front end HTTP, port 80, premium, reserved a new static IP address
  • I pointed my domain at the new load balancer

It's worth mentioning at this point I tested I could access the web page stored on the VM without any issues.

  • I then created a HTTPS front end, protocol HTTPS, port 443, premium
  • I set the value of the IP to be the same as the value of the static IP I reserved when creating the HTTP front end.
  • I created a new google cloud managed certificate, which was provisioned successfully

At this point I tested again and could no longer access the site and I received the 502 error on the web page.

  • I created two firewall rules both set to ingress, allow-health-checks, 130.211.0.0/22 35.191.0.0/16. the only difference between the two is one is set to tcp 80 and one is set to tcp 443, I was just trying to cover off both in case. I also did try one without the other but that made no difference.

Now I am pretty stuck as I am not seeing any other potential steps I could take to resolve this issue.

I would be grateful for any potential solutions.

Cheers

1
google-cloud-platformgoogle-compute-enginegoogle-cloud-load-balancer
What is the error you are seeing under the load balancer menu? You can also check this official troubleshooting steps for load balancer in GCP. Also, is this the guide you followed? if not, you can use this as reference to your use case. - Alex G
Hi @AlexG firstly, thanks for coming back. - Scott Godfrey
The guide that best suited my use case was this one docs.bitnami.com/google-templates/how-to/… and these were the steps I have followed. However when I encountered problems I did review the guide you have provided a link to. as well as a number of other google docs "health checks overview", "trouble shooting HTTP(S)" load balancer" "setting a simple HTTP load balancer" "SSL Certificates overview" & a few more besides. There is no error aside from a yellow flag indicating that 1 backend service is unhealthy - Scott Godfrey

1 Answers

1
votes

I managed to overcome this issue by following this guide. https://www.jiyuulife.net/google-cloud-cdn-for-gcp-wordpress/ In case anyone has similar issues.

There isn't a lot of good material out there for unmanaged IG's linked to existing VM's. I found even googles documentation to be a little light on the subject. Sometimes you do want to provide load balancing to existing VM's to make use of CDN without the redundancy or expense.

I welcome additional contributions here.