NSX Load Balancer exceeds maximum number of rules in virtual server

Products

• VMware NSX

Issue/Introduction

When there are more than a total of 512 rules configured in a NSX LB service, the load balancer may not be initialized properly therefore the Virtual Servers communication through this LB service may not work properly. 

In NSX manager syslogs, there maybe similar log entry as following:

2025-04-15T20:11:07.305Z <nsx-manager-node> NSX 13049 POLICY [nsx@6876 comp="nsx-manager" errorCode="PM502110" level="ERROR" reqId="<request-UUID>" subcomp="manager" username="admin"] Exceed maximum number of rules in virtual server /infra/lb-virtual-servers/<virtual-server-name>. The maximum size of rules is 512, and current size of rules is 513.

 

 

Environment

VMware NSX

Cause

A load balancer scale validation is enforced by default in order to prevent performance degradation for the NSX edge node where the LB service is configured.

The number of virtual servers, pools, pool members, and rules that a Load Balancer service can have is limited when the validation is enabled.

Exceeding such limit will result in Load Balancer service not being initialized properly. 

Resolution

Please open a Broadcom Support Request and reference this KB.

In addition, please upload the following logs to the SR:

• All three NSX manager nodes
• The name of Load Balancer service/Virtual Service that is impacted

 

Additional Information

If using OpenShift, the load balancer is created as OpenShift Router. NCP watches OpenShift route and endpoint events and configures load balancing rules on the load balancer based on the route specification.

As a result, the NSX load balancer will forward incoming layer 7 traffic to the appropriate backend pods based on the rules and this number of rules can add up quickly when using OpenShift.