Splunk Enterprise Certified Architect SPLK-2002 Reddit Questions

The minimum reference server specification for a Splunk indexer is 12 CPU cores, 12GB RAM, and 800 IOPS. This specification is based on the assumption that the indexer will handle an average indexing volume of 100GB per day, with a peak of 300GB per day, and a typical search load of 1 concurrent search per 1GB of indexing volume. The other specifications are either higher or lower than the minimum requirement. For more information, see [Reference hardware] in the Splunk documentation.

According to the Splunk Search Head Clustering Troubleshooting Guide, when a Search Head Cluster (SHC) member is reverted from a backup or experiences configuration drift (e.g., an outdated Raft state), it can fail to rejoin the cluster due to inconsistent Raft metadata. The Raft database stores the SHC’s internal consensus and replication state, including knowledge object synchronization, captain election history, and peer membership information.

If this Raft metadata becomes corrupted or outdated (as in the scenario where a node is restored from backup), the recommended and Splunk-supported remediation is to clean the Raft metadata using:

splunk clean raft

This command resets the node’s local Raft state so it can re-synchronize with the current SHC captain and rejoin the cluster cleanly.

The steps generally are:

Stop the affected SHC member.

Run splunk clean raft on that node.

Restart Splunk.

Verify that it successfully rejoins the SHC.

Deleting configuration stanzas or forcing re-addition (Options B and C) can lead to further inconsistency or data loss. Reviewing logs (Option A) helps diagnose issues but does not resolve Raft corruption.

References (Splunk Enterprise Documentation):

• Troubleshooting Raft Metadata Corruption in Search Head Clusters

• splunk clean raft Command Reference

• Search Head Clustering: Recovering from Backup and Membership Failures

• Splunk Enterprise Admin Manual – Raft Consensus and SHC Maintenance

Splunk Enterprise officially requires a minimum of three search heads and one deployer for a supported Search Head Cluster (SHC) configuration. This ensures both high availability and data consistency within the cluster.

The Splunk documentation explains that a search head cluster uses RAFT-based consensus to elect a captain responsible for managing configuration replication, scheduling, and user workload distribution. The RAFT protocol requires a quorum of members to maintain consistency. In practical terms, this means a minimum of three members (search heads) to achieve fault tolerance — allowing one member to fail while maintaining operational stability.

The deployer is a separate Splunk instance responsible for distributing configuration bundles (apps, settings, and user configurations) to all members of the search head cluster. The deployer is not part of the SHC itself but is mandatory for its proper management.

Running with fewer than three search heads or replacing the deployer with a Deployment Server (as in Options B, C, or D) is unsupported and violates Splunk best practices for SHC resiliency and management.

References (Splunk Enterprise Documentation):

• Search Head Clustering Overview – Minimum Supported Architecture

• Deploy and Configure the Deployer for a Search Head Cluster

• High Availability and Fault Tolerance with RAFT in SHC

Of the following types of files within an index bucket, the rawdata file type may consume the most disk. The rawdata file type contains the compressed and encrypted raw data that Splunk has ingested. The rawdata file type is usually the largest file type in a bucket, because it stores the original data without any filtering or extraction. The bloom filter file type contains a probabilistic data structure that is used to determine if a bucket contains events that match a given search. The bloom filter file type is usually very small, because it only stores a bit array of hashes. The metadata (.data) file type contains information about the bucket properties, such as the earliest and latest event timestamps, the number of events, and the size of the bucket. The metadata file type is also usually very small, because it only stores a few lines of text. The inverted index (.tsidx) file type contains the time-series index that maps the timestamps and event IDs of the raw data. The inverted index file type can vary in size depending on the number and frequency of events, but it is usually smaller than the rawdata file type