Fixed : Cannot Create Property ‘Traceid’ On String ‘No Healthy Upstream

The error message “cannot create property ‘traceid’ on string ‘no healthy upstream'” typically indicates that your application or system is trying to assign a property (like ‘traceid’) to a string value instead of an object.

This can happen during error handling when the underlying issue is a “no healthy upstream” error.

This error:

“cannot create property ‘traceid’ on string ‘no healthy upstream’”

combines two issues: one is “no healthy upstream” and the other is a coding/logic error trying to treat “no healthy upstream” (a string) as an object and assign traceid to it.

What “No Healthy Upstream” Means

• This error means your load balancer or proxy (commonly in setups with Nginx, Kubernetes, or similar) can’t connect to any backend or upstream servers because all of them are unhealthy or unreachable.

• It commonly occurs when backend servers are down, failing health checks, or network issues block connections.

Why the “traceid” Error Happens

• Your code expects an object (e.g., JSON response) to attach the “traceid” property, but it receives a plain string “no healthy upstream” instead.

• This leads to a type error because strings cannot have properties assigned.

Also Read : Fixed : Cannot Install Extension Because it uses an Unsupported Manifest Version

How to Fix This

1. Check Backend Health

   • Confirm all backend servers are running and responding properly. Verify health checks are passing.

2. Inspect Proxy/Load Balancer Config

   • Review your load balancer (Nginx, Kubernetes ingress, etc.) configuration to ensure it correctly routes traffic and marks healthy upstream servers.

3. Add Error Handling for String Responses

   • Modify your code to check the type of the response before assigning properties. If you get a string error message, handle it without trying to add properties.

4. Check Logs for More Details

   • Review application, server, and load balancer logs to identify why upstreams are unhealthy or unreachable.

Summary

The root cause is the “no healthy upstream” server connectivity error. The “traceid” assignment failure is a symptom of incorrectly assuming the response is always an object. Proper health checks, configuration, and defensive programming will resolve this.