Rules of AEM

Prevent DDoS in Apache & IP Block Automation DDoS (Distributed Denial of Service) attacks are a type of cyberattack that can cause serious damage to your web server. These attacks involve flooding your server with a huge volume of traffic, overwhelming its resources and causing it to crash. In this blog post, we'll discuss how to prevent DDoS attacks in Apache, without using any third part tool/application.     Available Options to Prevent DDoS : You can use various mentioned methods to achieve the same. But using WAF, CDN, etc will cost extra dollars. Which might not be necessary for a small scale application.   Use a Web Application Firewall (WAF): A WAF can help detect and block malicious traffic before it reaches your Apache server. It can also help block common attack vectors, such as SQL injection and cross-site scripting (XSS). Install mod_evasive: mod_evasive is an Apache module that helps detect and block DDoS attac...

How to Configure CSP header in AEM ? Content Security Policy (CSP) is a security feature that helps prevent cross-site scripting (XSS) and other code injection attacks by restricting the sources from which a page can load resources. To implement a CSP header in an Apache web server, you can use the Header directive in your Apache configuration. Here are the steps to implement a CSP header in Apache: Determine your CSP policy: First, you need to determine your CSP policy. This policy defines the rules for what types of content can be loaded from which sources. You can use a CSP policy generator like the one available on the Mozilla Developer Network (MDN) website to generate a policy that meets your needs. Add the CSP header to your Apache configuration: Once you have your CSP policy, you can add the CSP header to your Apache configuration. To do this, open your Apache configuration file (usually located at /etc/httpd/conf/httpd.conf or a similar location depending on your setup) and ...

The dispatcher is used as a load balancing/caching tool by AEM. It can also be used to block anyone from accessing your AEM author instance. This is to ensure that no one outside the client’s network can access it. AEM Author and publisher should never be exposed directly. In most cases, clients may also require a block to be put on AEM pub dispatchers before going live. This is to ensure that no one can see the site except for the client so performance, penetration, and UAT testing can be performed before going live. In this article, we will see, 5 easy steps to enable IP whitelisting in Apache so only the allowed list of IPs have access to AEM through the dispatcher. 1) In Apache to enable whitelisting, the Require directive is used which is provided by the mod_authz_host module. Make sure that you have the module enabled first in  /dispatcher/src/conf.modules.do/00-base.conf LoadModule authz_host_module modules/mod_authz_host.so 2) In the ams default variable file /dispatcher/s...

How to Increase Apache Request Per Second ? By default, Apache web server is configured to support 160 requests per second. As your website traffic increases, Apache will start dropping additional requests and this will spoil customer experience.  Here’s how to increase Apache requests per second. 1. Install MPM module We need to install MPM Apache module to be able to increase Apache requests per second. You can use mpm_worker or mpm_event module for this, instead of mpm_prefork module which consumes a lot of memory. You can easily install MPM module in Apache with following command For CentOS7/RHEL7 : Adjust /etc/httpd/conf.modules.d/00-mpm.conf Comment the line LoadModule mpm_prefork_module modules/mod_mpm_prefork.so by adding # in front of it. Uncomment the line LoadModule mpm_worker_module modules/mod_mpm_worker.so by removing # in front of it. For Ubuntu/Debian :  Use a2dismod / a2enmod to disable mpm_prefork and enable mpm_worker 2. Increase Max Connections in Apach...

 Maven build is failing due to CHECKSUM issue.  AEM Developers, Infrastructure Engineers regularly come across a challenge on building the AEM code & dispatcher module use to get failed while mvn build. The article addresses in a simple way on how to understand the mechanisms of dispatcher module build, and gives a detailed explanation of how it can be resolved.  This is useful for  building the code for a deployment via Pipeline either it is Adobe Cloud manager or Jenkins, you can see this error while your local build itself.  This error is caused, as the dispatcher owner does not not want you to change/modify few of its default files which are marked as immutable in dispatcher server.  You can find full list of immutable files on of dispatcher provided by Adobe.  https://helpx.adobe.com/experience-manager/kb/ams-dispatcher-manual/immutable-files.html Issue :- In AEM while doing the deployment it is being seen , user get the exception , Maven ma...

AEM DISPATCHER STATFILE UNDERSTANDING & CACHE INVALIDATION:- AEM Developers, Infrastructure Engineers regularly come across a challenge on decoding the statfile and using it efficiently especially statfile becomes highly relevant in a multi-tenanted environment with different project teams controlling different sites. The article addresses in a simple way on how to understand the mechanisms of stat file and gives a detailed explanation of how it can be used in a multi-tenant environment model.  The image for your reference as a quick overview of the data flow, before we take a deep dive.  This article covers - 1 - When dispatcher serves the old version of the content. How to avoid it. 2- Cache invalidation mechanism. Assumption - If you are reading this article, I believe you would have a basic understanding of Dispatcher and it's configuration. Firstly let’s set the initial configuration for the cache invalidation section ...