Increasing Load balancer client side idle session timeout

Products

• VMware NSX

Issue/Introduction

Create an application rule to configure the session timeout value in NSX Load balancer.

Symptoms:

In Load Balancer setup, the session could timeout after 5 minutes, if the task appears idle to NSX LB. However, if you configure the application server directly bypassing the NSX LB, the transaction doesn't terminate within 5 minutes but finishes successfully.

Environment

VMware NSX for vSphere 6.2.x
VMware NSX for vSphere 6.3.x

Cause

Session timeout is the maximum connection inactivity time on the client side. The inactivity timeout applies when the client is expected to acknowledge or send data. In HTTP mode, this timeout is important to consider during the first phase, when the client sends the request, and during the response, while it is reading data sent by the server.

Resolution

Prior to NSX for vSphere 6.2.4 release, this value is unconfigurable, with the default value as 5 minutes.
In NSX for vSphere 6.2.4 and later releases, you can configure this value by application rule.

• Default value: 300s
• Units supported: us,ms,s,m,h,d

To create an application rule:

 

1. Navigate to Network and Security -> NSX Edges -> Double Click your LB Edge -> Manage -> Load Balancer -> Application Rules.
   Click + to create a new rule.
   Enter Name and Script as "timeout client 600s"
   Click OK.
    
2. Navigate to Network and Security -> NSX Edges -> Double Click your LB Edge -> Manage -> Load Balancer -> Virtual Servers.
   Click the Pencil icon to edit the virtual server > Advanced and select the application rule created.
   Click OK.

Note: It is not recommended to configure 2 virtual servers sharing the same pool with different session timeout settings. In case a pool shared by different virtual servers, the session timeout value of the pool corresponding backend is set as the maximum value of virtual servers.