AEM Dispatcher

What is AEM Dispatcher?

AEM Dispatcher is a web server module (provided by Adobe) that sits in front of an AEM instance and caches and delivers content to users. It acts as a proxy server that intercepts requests to AEM and serves cached content whenever possible. AEM Dispatcher can be used to cache both static and dynamic content, and it uses a set of rules and configurations to determine when to serve cached content and when to forward requests to AEM.

Key benefits of using AEM Dispatcher:

Improved performance: AEM Dispatcher reduces the load on the AEM instance by caching and serving content from the cache.

Reduced server load: By serving content from the cache, AEM Dispatcher reduces the load on the AEM server, allowing it to handle more requests and users.

Better security: AEM Dispatcher can be configured to provide an additional layer of security for AEM by blocking harmful requests and limiting access to certain resources.

Scalability: AEM Dispatcher can be used to distribute content across multiple servers, making it easier to scale AEM for large-scale deployments.

How AEM Dispatcher works:

AEM Dispatcher works by intercepting requests to AEM and checking whether the requested content is in the cache. If the content is in the cache, AEM Dispatcher serves it directly to the user.

If the content is not in the cache, AEM Dispatcher forwards the request to AEM, which generates the content and sends it back to AEM Dispatcher.

AEM Dispatcher then caches the content and serves it to the user. AEM Dispatcher uses a set of rules and configurations to determine when to serve cached content and when to forward requests to AEM.

Dispatcher setup for AEM as a cloud service in linux/mac using docker

Prerequisites for Dispatcher Setup

Apache 2.2 web server
Dispatcher Module
Docker setup in local

Installation Instructions

Install Apache web server

Run this command to install the apache package on ubuntu

sudo apt install apache2 -y

Install Docker

Run this command to install the latest docker package on ubuntu

sudo apt-get install docker-ce docker-ce-cli containerd.io
docker-buildx-plugin docker-compose-plugin

For Verify docker was installed correctly, Run this comman

docker --version

Execute

aem-sdk-dispatcher-tools-<version>-unix.sh

Run this command to execute script

chmod +x <fileName>

sudo ./<fileName>

aem

Validate the Dispatcher configuration contained in this SDK

$ sudo ./bin/validator full -d out src

This validates the configuration and generates deployment information in out

Validate the deployment information by the Dispatcher in a docker image

$ sudo ./bin/docker_run.sh out localhost:4503 test

This will start the container, run Apache in configuration test mode (httpd -t), dump processed dispatcher. any config (-D DUMP_ANY) and exit.

Confirm that no immutable config file was changed against a docker image ones

$ sudo ./bin/docker_immutability_check.sh src

With your AEM publish server running on your computer, listening on port 4503, you can start the dispatcher in front of that server as follows:

$ sudo ./bin/docker_run.sh out host.docker.internal:4503 8888

Sometimes, You may encounter this error “Waiting until host.docker.internal is available”, to resolve this use your host ip

bin/docker_run.sh src <HOST IP>:4503 8888