Graceful disable of the server within the pool fails with error "Field check for external_uuid failed : Reference field external_uuid contains bad characters"

Products

• VMware Avi Load Balancer

Issue/Introduction

• When attempting to gracefully disable a backend server within a pool, the operation fails, and the Avi Controller UI generates the validation error: Field check for external_uuid failed : Reference field external_uuid contains bad characters

Environment

• Avi Load Balancer
• Affected Version: 22.1.4 and Above

Cause

 

• Starting in version 22.1.4, a design change was introduced where the external_uuid field for pool servers is automatically populated using the virtual machine name defined in vCenter.

• The system validation engine requires that this identifier contain no blank spaces.

• If a backend server's VM name in vCenter contains a space, the external_uuid inherits that space, triggering a validation failure during configuration updates.

• Consequently, any subsequent API PUT calls to modify the pool such as gracefully disabling a server will fail with a field check error.

 

Resolution

Modify the server name within vCenter to eliminate all spaces, ensuring a clean string formatting before re-syncing the pool.