The best resource to help the customer gather the requirements for their new architecture is the Splunk Validated Architectures document. This document guides customers through various approved architectures that can meet their requirements, including considerations for scalability and high availability, which are essential for their situation.
The appropriate strategy to protect the searchability of the indexer cluster with the minimum and least disruptive change is to leave the replication factor at 2, increase the search factor to 2, and enable summary replication. Increasing the search factor ensures that there are enough searchable copies of the data, and enabling summary replication will safeguard summary data without requiring a complete overhaul of the system configuration or a more complex multi-site setup. This approach balances protection and minimal disruption to the existing cluster configuration.
The primary driver behind implementing indexer clustering in a customer's environment is to provide higher availability for buckets of data. Indexer clustering ensures that data is replicated across multiple indexers, which enhances the redundancy and availability of the data, thus preventing data loss in case an indexer fails.
The Monitoring Console (MC) should be installed on the cluster master node in a single indexer cluster, provided that the load on the master node is within acceptable limits. This centralizes monitoring and is often recommended unless specific conditions dictate otherwise, such as heavy load or SmartStore usage, which might necessitate hosting the MC on a dedicated search head.
When a user modifies a dashboard, the modified version is saved in the 'local' directory, which takes precedence over the 'default' directory where the application updates are stored. Therefore, when the app is upgraded, the updated dashboard will not override the user's modifications, and the user will continue to see their modified version.