This article contains information about enabling the Client Keep-Alive mode of a NetScaler appliance.

The Client Keep-Alive mode of the NetScaler appliance is similar to the Keep-Alive mode of the HTTP protocol. The Client Keep-Alive mode enables the NetScaler appliance to process multiple requests and responses using the same socket connection.

When the Client Keep-Alive mode of the NetScaler appliance is disabled and the server response to the client request contains the Connection: close HTTP header, the NetScaler appliance sends the HTTP header to the client without modifying the header, as shown in the following header of a sample response:

Hypertext Transfer Protocol
HTTP/1.1 200 OK
Response Code: 200
Connection: close
Content-Type: text/html; charset=utf-8
Content-Length: 29700

When the Client Keep-Alive mode of the NetScaler appliance is enabled and the server response to the client request contains the Connection: close HTTP header, the NetScaler appliance performs the following tasks before sending the response to the client:

• The appliance renames the existing Connection: header name by shuffling the characters in the header name, as show in the following sample. The header in the sample is bold faced for your reference.    

• The appliance adds a new Connection: header with Keep-Alive as the value for the header, as show in the following sample. The header in the sample is bold faced for your reference.

  HTTP/1.1 200 OK
  Response Code: 200
  Cneonction: close
  Content-Type: text/html; charset=utf-8
  Content-Length: 29700
  Connection: Keep-Alive
  

  Note: Some earlier or special application or Web pages are designed to only render the Web page after the browser receives the Connection: close header. This type of design has undesirable results that must be resolved in the application or Web page, or by disabling the Client Keep-Alive mode of the appliance.

Instructions

To enable the Client Keep-Alive mode of the NetScaler appliance, run any of the following commands from the command line interface of the appliance:

• To enable the Client Keep-Alive mode at the global level on the NetScaler appliance, run the following command:
  enable ns mode CKA

• To enable the Client Keep-Alive mode for a service on the NetScaler appliance, run the following command:
  set service <Service_Name> -CKA YES

For Configuration Utility Changes for NetScaler 10.1, refer Citrix eDocs - Configuration Utility Changes​.