High numbers of DNS queries are observed from an Aria Orchestrator cluster

Products

• VCF Operations/Automation (formerly VMware Aria Suite)

Issue/Introduction

• The DNS queries are the cluster querying DNS about its own nodes
• You see over 2000 queries in a 10 minute window

Environment

Aria Orchestrator 8.18.1

Cause

This is expected behavior on 8.18.1. 

It is expected that there can be a lot of DNS queries for the nodes hostnames, since all kubernetes components are configured to use the hostnames of the nodes, instead of IP addresses directly.

Some of the actions generating most queries are:

1. The node healthchecks queries for the hostname occur around 10 times every time it gets executed (every 5 seconds).
2. The Postgres database replication also uses the node hostname and also requires resolving them when it runs
3. etcd is configured to use the hostnames, and would query for them regularly

Resolution

This behavior is expected on Aria Orchestrator 8.18.1 and will be improved in future release(s).