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 a 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 publishing environments.

Major advantages are:
Performance
Scalability for reading 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.