HTTP Keep Alive

Overview

Use the HTTP Keep Alive rule to manage persistent client-to-CDN connections for faster content delivery, reduced latency, and improved performance.

Connection pooling and connection reuse is enabled by default by Qwilt CDN. The HTTP Keep Alive rule lets you control how long idle connections are kept open before being closed.

Configure the Rule

Here, we'll describe how to configure the rule with the Delivery Service Management UI.

API Users may choose to build the site configuration offline.

To configure an HTTP Keep Alive rule:

1. Navigate to the Select Rule dialog.

2. In the Select Rule dialog, choose HTTP Keep Alive.

3. Set the Maximum Idle Timeout parameter:

   • Specify the number of seconds that an idle connection remains open, rather than being closed immediately when a request is fulfilled.
   • The default is 60 seconds.
   • The maximum supported for client-to-CDN connections is 300 seconds.

4. Choose Add Rule.

SVTA Component: QW.ClientConnectionControl

When you save the configuration version, the QW.ClientConnectionControl component is added to the JSON configuration.

This is a private feature developed by Qwilt. In the JSON format, private features are nested within the MI.PrivateFeaturesList object, in the "generic-metadata-value" "features" field.

In this example, the rule is configured to leave connections open for 80 seconds.

{
    "generic-metadata-type": "MI.PrivateFeatureList",
    "generic-metadata-value": {
        "features": [
            {
                "feature-type": "QW.ClientConnectionControl",
                "feature-oid": "Qwilt",
                "feature-value": {
                    "connection-keep-alive-time-ms": 80000                    
                }
            },

Note that in the SVTA object, the maximum idle timeout value is expressed in milliseconds.