AEM With TarMK - Options

We can have 3 types of TarMK configurations for AEM Oak Clusters.

1) Single TarMK Instance

A single TarMK instance runs on a single server. For Author instances, this is the default deployment method.

Major advantages are,

• Simple
• Easy to maintain
• Better performance

The disadvantages:

• Scalability is within the limits of server capacity
• No failover capacity

2) TarMK Cold Standby

Here single TarMK instance acts as the primary instance & the repository from the primary is replicated to a standby, which acts as failover system.

Major advantages are,

• Simplicity
• Maintainability
• Performance
• Failover

The disadvantages:

• Scalability is within the limits of server capacity
• There is a manual task involved in detecting failure and failover to start working

3) TarMK Farm

Multiple Oak instances are involved and each Oak instance is running with one TarMK. All TarMK repositories are not in sync
TarMK Farm is the default deployment for publish environments.

Major advantages are,

• Performance
• Scalability for read access
• Failover

Final notes:
Always remember this. Adobe highly recommends TarMK as the default persistence technology for both the AEM Author and Publish instances, except in the use cases outlined here.
Videos on AEM & Persistence
AEM Persistence TarMk & MongoMK Series 1
AEM Persistence TarMk & MongoMK Series 2  AEM with TarMK
AEM Persistence TarMk & MongoMK Series 3  AEM with MongoMK
AEM Persistence TarMk & MongoMK Series 4  TarMK Vs MongoMK
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Rule Engine integration with AEM

Search, Persistance Manager in AEM/CQ

Search:

There are two supported query languages in AEM

• SQL2
• XPATH

Accessing query browser

Tools>Query open query browser

Readable: http://helpx.adobe.com/experience-manager/using/querying-experience-manager-data-using1.html

To read on integrating CQ with Solr search, visit blog: Integrating AEM/ CQ with Solr search

Persistence manager:

Persistence manager helps to save the repository content to a permanent storage solution, such as the file system or a database.

All content is stored in file system in form of tar file at below location.

Location of persistence manager

AEM/CQ install directory-> Author->crx-quickstart->repository->workspaces->crx.default->data_00000.tar

Configuring/modifying the persistence manager location/type

Default tar is <PersistenceManager class="com.day.crx.persistence.tar.TarPersistenceManager"/>

AEM/CQ install directory-> Author->crx-quickstart->repository->repository.xml

MySQL Persistence Manager: Stores the workspace content in a MySQL database.       

Configuration:

<PersistenceManager class="org.apache.jackrabbit.core.persistence.bundle.MySqlPersistenceManager">

<param name="driver" value="com.mysql.jdbc.Driver"/>

<param name="url" value="jdbc:mysql://localhost:3306/crx"/>

<param name="user" value="userid"/>

<param name="password" value="password"/>

</PersistenceManager>

Backups & restore CQ files

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AEM provide online & offline backups.

Online:Online method creates a backup of the entire repository, including CQ5. We can perform this method while the repository is in use.

Offline:Creates a backup of the CRX repository files including all of the information stored in CRX, so you can restore the exact state of the repository during backup.

Also incremental so it updates only next day components to backup.

Read More: 
Solr and AEM
JSON for Solr
AEM INTERNALIZATION
Search Persistance
Navigation in AEM
Website design steps in AEM