SE might go down after running show virtualservice dnstable command

Products

• VMware Avi Load Balancer

Issue/Introduction

This issue is only applicable to GSLB environments with large scale (> 7k-8k GSLB services). 
The symptoms include:

• SE might go down after running show virtualservice <dns-vs-name> dnstable command
• SE might go down if VS tech-support collection is triggered for a DNS VS as the above dnstable command is invoked during the tech-support collection process. 

Below is an example of stack trace from such a Service Engine failure. This stack trace would be found by navigating to Administration>Support>Crash Reports.

Environment

This issue is only applicable to GSLB environments with large scale (> 7k-8k GSLB services). 
Versions affected: 22.1.x, < 30.2.4, < 31.1.2, < 31.2.1

Cause

In scenarios involving a significantly large DNS table, attempts to display its contents may cause SE failure due to system limitations in internal memory allocation. 

Resolution

A fix has been added to 22.1.7-2p11, 30.2.4, 31.1.2, 31.2.1 where the invocation of this command won't cause SE failure but the command won't work if the DNS table output exceeds internal system limits. 

We will be implementing a filter argument with the command to enable admins to just check the DNS table for a specific FQDN. This enhancement will be introduced in a future release.