China CDN Deployment Extension

You can use this extension when you cannot modify the source code for a web site to add logic to determine the user’s location. This extension is also useful when a profile that primarily serves content from outside of China receives a small amount of traffic from within China.

If a large amount of your traffic is from China and you can modify the source code for your web site, we recommend that you create a dedicated profile for the .cn domain and add a customized script to the HTML code you paste in each page. For more information, see Update the code for your website.

Prerequisites

• To create a draft of a China CDN Deployment extension, you need the Manage JavaScript Code Extensions account-level permission.

How it works

The China CDN Deployment extension consists of a code editor pre-filled with JavaScript code that is executed during the pre-loader scope. This code contains logic to do the following:

• Determine the user’s location based on their browser language, timezone, and IP address.
• Set a cookie with the best CDN for that user.

All subsequent site visits read the cookie value, if it is present, and fetch all utag content from the most specified CDN. Setting the cookie in the pre-loader scope means that the initial page request is served from the appropriate CDN.

Page load speeds will be impacted if content is delivered to China from outside the Chinese network. However, after the initial page load and setting of the CDN cookie, the extension will deliver available resources from the China CDN to China-based users to speed up their requests.

Configuring the extension

When you add the China CDN Deployment extension to a profile, an Ace Editor window is displayed, which contains the default code for the extension. You can configure the domainMap, languageMap, and gmtMap variables for the extension. In addition, you can specify the matchLogic to determine a user’s location.

Setting up domain mapping

If you have multiple domains associated with a profile, you use the domainMap variable to direct all domain traffic to a specific CDN.

domainMap = {
    'www.yourwebsite.cn': 'cn'
},

Adjusting language mapping

The languageMap variable lists the most common Chinese language variations and maps them to a single CDN.

languageMap = {
    'zh': 'cn',
    'zh-HK': 'cn',
    'zh-CN': 'cn',
    'zh-TW': 'cn'
},

Adjusting timezone mapping

The gmtMap variable specifies the Chinese time zone.

gmtMap = {
    '-480': 'cn'
},

Adjusting the match logic

The default matchLogic variable for all defined variables requires them to all be true. Set it to or if only some of the variables need to be true.

matchLogic = 'and'; // 'or'

Turning IP location detection on or off

• If locationTest is true, fetch the users IP address and return a location.
• If locationTestForce is true, runs the location logic every time regardless of the cookie value or other match logic results.
• Both variables default to true to provide optimal location detection for every user session.

 var locationTest = true; // Use location test logic
 var locationTestForce = true; // Use location test in all scenarios

Adjusting the cookie duration and when to trigger a retest

The retestTime variable is specified in milliseconds and specifies when the retest is done to determine the user’s location. The default is one day.

var retestTime = 86400000; // 1 day