Recommendation of a Strategy

The Secret Life of CQ Dispatcher

Venu Gummadala

What is a Dispatcher?

A load balancing &

A caching tool

Dispatcher A Load Balancer

CQ1CQ1CQ1CQ3CQ2

Web server

Dispatcher

www.

Client

Dispatcher A Caching Tool

CQ

Web server

Dispatcher

www.

Client

Dynamic Content

Remote Content

Static Content

Why Use It ?

As a load balancer prevents system from crashing by distributing requests among cq server instances.

As a caching tool improves performance by serving static content locally from your web server.

But

You can also use it behind a physical load balancer.

You can also use it for a single CQ instance.

It is also valid for both Author & Publisher environments.

But .. why not CDNs?

*should not be compared with CDNs really

CDNs are also caching tools

CDNs serve digital assets from a geographical location near to you

CDN is a implemented using a Provider

Dispatcher is OTB and made for CQ

more than a CDN

By serving static content from Web server process it reduces load on CQ server

By enforcing rules it filters un-wanted traffic at the web server level itself

By re-writing urls it protects CQ from hackers realizing the content paths

By blocking url patterns, headers ensures added protection & system failure.

more than a CDN... Continued

Gives the ability to include SSIs before request goes to CQ instance

Improves User Experience on the site by responding quickly when serving static content

Finally .. gives more control how you mange (delete or retain) cached files

Just a module and a config file to be used on a web server

Usually obtained from daycare

Supported web servers :-
Apache Web Server 2.0, 2.2 & 2.4
Microsoft IIS 7.0, 7.5 & 8.0
& Oracle iPlanet Web server 7.0

Instructions to install
dev.day.com/install

How to install?

How to configure?

Edit your dispatcher.any file using any Editor.

Sample dispatcher code structure..
/website

{ /clientheaders{}/virtualhosts{}/sessionmanagement {}/renders{}/filter{}/cache{/rules{}* preconfigured sample file here

/cache{ /docroot "/opt/dispatcher/cache" /statfile "/tmp/dispatcher-website.stat" /allowAuthorized "0"

/rules{/0000 { /glob "*" /type "allow" }/0001 { /glob "/en/news/*" /type "deny" }/0002 { /glob "*/private/*" /type "deny" } }What is cached ?
Ans: Everything (specified by '*' and 'allow')

What is not cached? ( Or what not to cache ? )
Ans: Content under /en/news path & url containing private path

Why ? Ans: news can be a feed getting constant updates
private can be personalization or profile data

What is docroot?Ans: location on your webserver where cached content is saved

What is a statfile?
Ans: A file that manages the register of the last time the content was updated

What is allowAuthorized?Ans: A flag to indicate if auth header, auth cookie & login-token cookie can be cached

What is Cached ?
& what is not ?

What is not Cached

Urls without file extensions e.g. /content/en is not cached

Urls with query string parameterse.g. /content/en/blog/recipe.html?user='amy' is not cached

HTTP 'post' method

HTTP response status != '200 OK'

Header response with 'Dispatcher: no-cache'

What is Cached ? ... Continued
& what is not ?

Dispatcher As a Security Tool

Use filter to allow/deny actions & access to paths/content/tools

Example

/filter {/0001 { /type "deny" /method "POST" /url "/etc/*" }/0002 { /type "allow" /method "GET" /url "/etc/*" /query "a=*" } /0003 { /type "deny" /glob "GET *.infinity.json*" }/0004 { /type "allow" /glob "* *.js *" } # enable javascript/0005{/glob "* /publish/libs/cq/workflow/content/console/archive*"/type "deny" }}

0001: Deny all POST methods0002: Allow GET methods with query parameter = a0003: Prevent json content dumps0004: Allow javascript resource files 0005: Deny access to protected areas & tools .. workflow console in this case.

Dispatcher As a Security Tool

Use virtualhosts forDomain mapping

Re-write urls etc.

Example

/virtualhosts{"www.isoap.com"}/renders{/hostname "internal.isoap.com"/port "4503"}

Appendix

What is static content ? Content which may remain un-changed for a specific amount of time. For e.g. images, scripts, error pages etc.

What is Dynamic Content?Content which may change with time such as a Sports Score Card, User Blogs, News etc.

More ?

dev.day.com/more

Even more ?

How to configure a publisher environment ?

Even more performance tweaks ?

Deployment landscape & process ?

For commercial implementationsContact: Venu.Gummadala@gmail.com

Thank you ...