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Showing posts with the label cache

How to prevent DOS attacks in AEM ?

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Prevent Denial of Service (DoS) Attacks : AEM  A denial of service (DoS) attack is an attempt to make a computer resource unavailable to its intended users. You can get more information on DDoS prevention in Apache At the dispatcher level, there are two methods of configuring to prevent DoS attacks: Use the mod_rewrite module (for example,  Apache 2.4 ) to perform URL validations (if the URL pattern rules are not too complex). Prevent the dispatcher from caching URLs with spurious extensions by using  filters .  For example, change the caching rules to limit caching to the expected mime types, such as .html .jpeg .gif .swf .js .doc .pdf .ppt .... as per your project requirement. An example configuration file is given below,  for  this includes restrictions for mime types.      When configuring Dispatcher you should restrict external access as much as possible. The      following example provides example for the minimal access for external visitors, you can refer the default file.  /fi

Dispatcher flush from AEM UI

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How to Delete Dispatcher cache without logging into the Dispatcher servers? Our Authoring team faces day to day challenges while deleting/flush the dispatcher cache. when the changes are not visible on server. They have to be depended on the IT operations/Dev ops teams to do the same. Which some time get very much time consuming for a small work.  In this article we will see it can be configure and used by Author UI itself.  This will allow  AEM authors (or “super authors”) to flush parts of the dispatcher cache manually without the involvement of IT Operations. How to Use 1. Log in to AEM Author 2. Download the ACS commons tool from  ACS Commons Official page 3. Install the downloaded package via aem package manager.   4. Make sure you create the dispatcher flush agents on Author for all Dispatchers. from http://<<host:port>>/miscadmin#/etc/replication/agents.author, check the NOTE's part at the end of page. 5. Navigate to Tools 6. Under the acs-commmons/dispatcher-flu

AdobeDispatcherHacks ".statfile"

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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 of the dis