A presentation by Jai Prakash and Vinod Bhasyam from Sapient, presented at Sitecore User Group Bangalore - August 2015 meetup held at Verndale, Bangalore.

1. Sitecore Personalization for websites cached on CDN Servers

2. SAPIENTNITRO CMS PRACTICE

3. SapientNitro’s expertise on CMS is based
on years of work with some of the world’s
leading brands and marketers…

4. 4
OUR RELATIONSHIPS AND EXPERIENCE WITH
MARKETING PLATFORM PARTNERS ARE SOLID
We have built strategic alliances with the leaders in the digital marketing technology vendor ecosystem
Cross-channel
Analytics Rich Media
Content
Management
Social Commerce
& Collaboration
Digital Asset
Management
Search
Relationship Marketing,
Campaign Management,
Production Automation

5. 5
 We have been global strategic partners with Sitecore since
2010
 Executive level relationships, monthly & quarterly
partnership communications rhythm, data points and
measures
 Strategy and Co-Investment Plan that includes enablement
activities, Global / Regional Account Planning (with focus
on NA, Germany and APAC)
 Leveraging Sitecore partnership on Engineering and
Technology initiatives
Our Relationship with Sitecore

6. 6
KEY SITECORE
CLIENTS

7. Context
The definition

8. 8
Context
When building enterprise-scale distributed applications, we might face many
performance related challenges. Caching mechanisms can increase performance by storing
copies of data accessed frequently from external systems in a high-performance
subsystem thus,
 Reducing round-trips
 Moving content closer to clients
 Avoiding time-consuming processes of regenerating reusable content
 Improved Performance
 Better Availability
 Scalability
A wide variety of caching techniques exist for caching within web applications.
Some of them include:
 ASP. Net Caching
• Page Level Output Caching
• Fragment Caching, User Control Output Caching
• Caching API, Using the Cache Object
 IIS Caches
 Client Caching

9. 9
Context
Enabling full Page level caching using some of the techniques mentioned above we may
lose out on the personalization features offered by Sitecore.
During the course of this session we will understand why caching is important and how
we can make the Sitecore personalization work even with full page level caching.

10. CACHING OPTIONS IN SITECORE
The details

11. 11
Cache Types
 HTML Cache
 HTML Cache (also known as the Output cache) associated
with each managed Web site contains the output generated
by individual renderings under different conditions.
 Item Cache
 Contains objects of the Sitecore class
Sitecore.Data.Items.Item that are used in the code most of
the time.
 Data Cache
 Contains items of the Sitecore class ItemInformation,
pulled from the database whenever they are requested.
 Prefetch Cache
 Contains items that Sitecore accesses during and
immediately after initialization and items with children
that Sitecore often accesses as a group.

12. 12
HTML Cache
 HTML output cache caches the actual HTML generated by the Sublayouts and Renderings.
You can configure the allowed size of the HTML cache and whether it should be enabled
or not for each of your managed websites.
<site name = "website" virtualFolder="/" physicalFolder="/"rootPath="/sitecore/content " startItem="/Home" database="web“
domain="extranet" cacheHtml="true" htmlCacheSize="10MB”
enablePreview="true" enableWebEdit="true"enableDebugger="true" disableClientData="false" />
 HTML output cache can be configured for each of the presentation controls. Each
presentation control can generate different output under different conditions, which
can result in multiple entries in a site HTML output cache for a single presentation
control.
 HTML output cache criteria for the presentation control can be set at the following
locations:
• In the Caching section of the rendering/sublayout definition item.
• In the Caching section of the properties of the presentation control when it is
assigned to a layout.
 HTML output cache can be specified to vary by on different parameters.

13. 13
Item Cache
 Item cache contains objects of the Sitecore class Sitecore.Data.Items.Item, which are
used in the code most of the time. Item cache gets generated for each of the databases.
 When you request for an item, which isn’t present in the item cache, it will get it
from the data cache and then populate it in the item cache as an Item.
 The purpose for this cache is to gain performance so that the ItemInformation objects
don’t need to get parsed into an Item each time they are requested.
 Item cache size can be set for each of the databases in the /databases/database
section.
<cacheSizes hint = "setting">
<data>20MB</data>
<items>10MB</items>
<paths>500KB</paths>
<standardValues>500KB</standardValues>
</cacheSizes >

14. 14
Data Cache
 Data cache contains items of the Sitecore class ItemInformation, which also is more or
less the item data pulled from the database.. Data cache gets generated for each of the
databases.
 Data cache gets populated whenever it is requested. The data is pulled from the
prefetch cache, if it present there; else it is pulled out of the database, put into
the prefetch cache and into then the data cache.
 The purpose of this cache is to minimize the amount of requests to the database. This
is extremely important for performance, as requesting items from the database is rather
expensive.
 Data cache size can be set for each of the databases in the /databases/database
section.
<cacheSizes hint = "setting">
<data>20MB</data>
<items>10MB</items>
<paths>500KB</paths>
<standardValues>500KB</standardValues>
</cacheSizes >

15. 15
Prefetch Cache
 Prefetch cache contains items of the Sitecore class PrefetchData, which is more or less
item data pulled out from the database. Prefetch cache gets generated for each of the
databases.
 Prefetch cache gets populated by pulling items out of the database at Sitecore startup.
 The purpose of this cache is to trade longer startup times for faster load times at
runtime.
 The items which should be loaded at start up are specified in the config files
specified in /app_config/prefecth folder. The items which are loaded are a combination
of the items specified in the config file for the specific database, for instance
master.config, and the common.config file.
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<cacheSize>20MB</cacheSize>
<template desc="reference">{EF295CD8-19D4-4E02-9438-94C926EF5284}</template>
<template desc="menu item">{998B965E-6AB8-4568-810F-8101D60D0CC3}</template>

16. 16
Clearing of Caches
 HTML cache: The HTML is always cleared on publish. So whenever you publish even a
single item the complete cache is cleared. This is due to the fact, that parts of the
HTML can be built from multiple items, so the cache has no way of knowing if the item
being published has influence on the presentation.
 Item cache: The Item cache gets cleared for items once they are published or updated.
If you publish an item which might influence other items, these items are cleared as
well. For example if you publish standard values or a template, that clears more than a
single item. The item cache is rebuild incrementally when the items are requested
again.
 Data cache: The data cache gets cleared for items once they are published or updated.
It is rebuild incrementally when the items are requested again.
 Prefetch cache: The Prefetch cache gets cleared in the same way as the item and data
cache, but the items specified in the Prefetch config files are pre-fetched from the
database again.

17. CDN CACHING
The usage

18. 18
WHAT IS CDN?
A content delivery network or content distribution network (CDN) is a large distributed
system of servers deployed in multiple data centers across the Internet. The goal of a
CDN is to serve content to end-users with high availability and high performance. CDNs
serve a large fraction of the Internet content today, including web objects (text,
graphics and scripts), downloadable objects (media files, software, documents),
applications (e-commerce, portals), live streaming media, on-demand streaming media, and
social networks. Some of the more known CDNs are Akamai, Amazon CloudFront, Cloudfare,
Fastly, MaxCDN, Cachefly etc.

19. 19
CDN CATEGORIES
 PULL
 Transfer Protocol: None
 Pros:
• Requires virtually no setup at your end: all you have to do, is rewrite
the URLs to your files: replace your own domain name with the CDN’s domain
name.
 Cons:
• No flexibility. It will just re-sync files based on the TTL set.
• Results in redundant traffic because files are being pulled from the origin
server more often than they actually change
 PUSH
 Transfer Protocol: FTP, SFTP, WebDAV, Amazon S3
 Pros
• Flexibility as you can decide when files are synced, how often and if any pre-
processing should happen.
• No redundant traffic
 Cons
• Requires a fair amount of work at your end to sync files to the CDN

20. 20
CDN Caching and TTL (Time-To-Live)
One of the most useful features to implement on a CDN-powered webpage is to define the
“Time To Live” (TTL) for file types. Time-To-Live (TTL) is a mechanism to limit the
lifetime of data in a network. Our Content Delivery Network (CDN) providers offer this
configuration setting. This will tell our CDN servers how long to wait before checking
for a changed/updated version of the file. When the time-to-live time has passed, a GET
request for an object triggers an IMS (If-Modified-Since) request to the origin server.

21. Personalization
Making Personalization work !!!

22. 22
What is Personalization?
Personalization is the practice of dynamically tailoring your site based on individual
users characteristics or preferences.
A key feature of Sitecore is its ability to personalize content according to pre-
defined sets of criteria, defined by content authors or marketers .

23. 23
Making Personalization Work on CDN Cached Pages
 Setup an Ajax Device in Sitecore that
will return the Rendering component
HTML based on the useAjax=true query
string parameter and the component
placeholder name that is passed
dynamically.
 Define an Ajax Layout that will be the
default layout to be used for an Ajax
Device. add an Ajax placeholder.
@using Sitecore.Mvc
@Html.Sitecore().Placeholder("ajax")

24. 24
Making Personalization Work on CDN Cached Pages
 Create an Ajax Controller to handle
the Render action that will get
triggered when an item is queried for
Ajax Device and the placeholder name
for the component is passed as a query
string parameter.
Render action will identify the
rendering on the page that matches
the placeholder parameter passed in the
query string. It will then fetch the
HTML for the same using the
PipelineService to run the
mvc.renderRendering pipeline.
Create a Controller Rendering
RenderAjax that will call the Render
action of Ajax Controller.
public ActionResult Render(string placeholder)
{
var html = string.Empty;
foreach (var r in PageContext.Current.PageDefinition.Renderings.Where(r =>
r.Placeholder == placeholder))
{
try
{
using (var stringWriter = new StringWriter())
{
PipelineService.Get()
.RunPipeline("mvc.renderRendering", new RenderRenderingArgs(r,
stringWriter));
html += stringWriter.ToString();
}
}
catch (Exception ex)
{
Logger.Log(ex.Message, ExceptionCategory.Fatal);
}
}
return Content(html);
}

25. 25
Making Personalization Work on CDN Cached Pages
 Associate the default Ajax Layout and
RenderAjax component with the Ajax
Device by adding it on the standard
values of the Base Page Templates.

26. 26
Making Personalization Work on CDN Cached Pages
 Create a View Rendering for the Ajax
Container that will control the
addition of “Personalized-Content”
placeholder in the page edit or preview
mode so that we can benefit from OOTB
Sitecore personalization features in
preview or page edit mode.
In the normal mode it will add the
container div with a unique class name,
personalized-content, and the data
attributes for the page item url and
unique placeholder name.
Include the JavaScript that will
trigger the Ajax call for any div with
the unique class name personalized-
content by reading the data-item-name
and data-placeholder-name data
attributes. The Ajax url will be formed
as below:
@inherits WebViewPage
@using Sitecore.Mvc
@{
var str = "Personalized-Content" +
Sitecore.Mvc.Presentation.RenderingContext.Current.Rendering.Parameters["Unique
Identifier"];
if (Sitecore.Context.PageMode.IsPageEditor ||
Sitecore.Context.PageMode.IsPreview)
{
@Html.Sitecore().Placeholder(str)
}
else
{
var url = Request.Url.AbsolutePath;
var placeholder =
@Sitecore.Mvc.Presentation.RenderingContext.Current.Rendering.Placeholder + "/" +
@str;
var ajaxID = placeholder.Replace("/", string.Empty);
<div class="personalized-content" id="@ajaxID" data-placeholder-
name="@placeholder" data-item-name="@url" ></div>

27. 27
Making Personalization Work on CDN Cached Pages
 Add the Ajax Container View rendering
before adding a personalized component.
Ajax Container should be placed in the
same placeholder as the personalized
component. Thereafter, add the
personalized component to the
“personalized-content” placeholder
added by the Ajax Container.
 Add a separate Ajax Container for each
personalized component added on the
page.
 In case multiple Personalized
Components are added on the same
placeholder then use the Rendering
Parameter “Unique Identifier” to make
the placeholder name unique by
appending a numeric value after the
personalized content

28. 28
Making Personalization Work on CDN Cached Pages
 Define a rule on the CDN servers not to cache any urls that contain the query
string ?useAjax=true. Thus the output of the ajax urls will not get cached and the
request will always come to the server.
url = <<data-item-name>> + "?useAjax=true&placeholder=" + <<data-placeholder-name>>;

29. © 2013 SAPIENT CORPORATION | CONFIDENTIAL
Demo

30. Analytics
How to handle!!!

31. 31
Enabling Sitecore Analytics Session on CDN
In order to access the Sitecore Analytics data for personalization rules that are
based on user visit information it is important to instantiate the Sitecore
Analytics session on CDN by dropping the Sitecore Analytics cookie in user’s
browser.
This can be achieved by adding a light weight ‘TrackExternal.aspx’ page in your web
application just to instantiate the Sitecore Analytics session from CDN. This page
will not have any code logic except a no-cache header.
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="TrackExternal.aspx.cs" Inherits=“sample.web.ui.website.TrackExternal"
%>
<%@ OutputCache Location="None" VaryByParam="none" %>
Include a Pixel tracking code(beacon) as below in your base layout that will
trigger a call to ‘TrackExternal.aspx’ page for every page request thus ensuring
that the Analytics session is available on CDN as well.
<img id="trackVisitor" src="@UriHtmlHelper.FormatAbsoluteUrl(Request.Url, "/TrackExternal.aspx")" alt="Tracking Image" height="1"
width="1" style="border-style:none;display:none;" />

32. © 2013 SAPIENT CORPORATION | CONFIDENTIAL
Q&A

33. © 2013 SAPIENT CORPORATION | CONFIDENTIAL
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