Client IP persistency issue due to delay in KV pair sync

Products

• VMware Avi Load Balancer

Issue/Introduction

All requests from a given user/Client are not hitting the same application server even after configuring "System-Persistence-Client-IP"

Environment

vCenter Cloud

Cause

All connections from the same client are coming in with around few milliseconds difference and they are landing on different SEs. Within this time, KVs are not yet synced to peer so they are landing on different ApplicationServers.

 

Resolution

Once this is enabled multiple flows for the same source IP address to be handled by the same SE.Eventually this issue will be fixed as persistency won't break.

> configure virtualservice <vs-name> 
virtualservice> flow_dist consistent_hash_source_ip_address
virtualservice> save

Caveats:

1.Make sure client's IP's are distributed else most the of the traffic will land on one SE.

2. This may NOT work well for ECMP based scaleout environment.(Eg: NSX-T,GCP,Azure,BGP Deployments etc.)