API calls may fail with "Timed out while executing the checks!"

Products

• VMware Avi Load Balancer

Issue/Introduction

• In environments utilizing highly consolidated Parent/Child configurations with large-scale sharing of services and pools, API configuration updates for the shared objects may fail. Users will encounter the following error message in the UI or API logs:
  

  Timed out while executing the checks!

• This timeout typically prevents administrators from successfully saving changes, adding new resources, or modifying existing services within the affected deployment tree.

Environment

• This issue specifically impacts large-scale, consolidated architectures utilizing Parent/Child Virtual Service configurations combined with extensive pool layouts and inline DataScripts.
• Your environment is highly susceptible to this issue if it meets the software version criteria and approaches or exceeds the deployment scale profile outlined below.

Applicable Versions:

• VMware Avi Vantage: All versions prior to 30.2.7 (e.g., 22.1.x, 30.1.x, and early 30.2.x releases).

Vulnerable Environment Scale Profile:

• The symptoms typically surface in deployments where a massive configuration tree is anchored to a single logical routing point.
  This issue was first discovered in an environment with the following scale:

Component	Vulnerable Baseline Scale
Parent Virtual Services	1
Child Virtual Services (EVH/SNI)	100+
Total Configured Pools	600+
Virtual Services with Active DataScripts	30+

 

Cause

The failure is caused by an exponential increase in control plane calculation overhead during configuration updates.

• Full Tree Traversal: Whenever a modification is made to a Parent VS, Child VS, or an associated pool, the Avi Controller cannot isolate the change. Instead, it must traverse and validate every single shared service, pool, and DataScript within that logical tree.

• Multiplicative Complexity: The runtime validation logic scales multiplicatively over these dimensions rather than linearly.

• Resource Exhaustion: As the scale of these shared dimensions increases, the time required for the controller to execute its dependency and security checks rises exponentially, ultimately exceeding the API response timeout.

Resolution

• The validation logic has been optimized to handle large-scale, highly cross-referenced configuration trees efficiently, drastically reducing calculation overhead and preventing API timeouts.

• Please find the fix details below:
  • Bug ID: AV-267339
  • Details: When a pool is shared by many Virtual Services, PATCH update calls to the pool fail with the error Cannot change Pool because of referred Virtual Service: Timed out while executing the checks!.
  • Release notes: Click here for the 30.2.7 release notes.  
  • Upgrade checklist for 30.2.7: Click here for the checklist.