Handle Raft issues
If the Raft metadata that underlies search head clustering gets into a bad state on a member, you can often correct the problem by cleaning the member's
var/run/splunk/_raft folder. See Fix Raft issues on a member.
If the cluster is unable to elect a captain and maintain a healthy state due to Raft issues, you can clean the Raft folder on all members and then bootstrap the cluster. See Fix the entire cluster.
Fix Raft issues on a member
The primary symptom of a Raft issue is that the member's status appears as "down" when you run
splunk show shcluster-status on the captain. To confirm the Raft issue, look in the member's
splunkd.log file for an error message that starts with the string "ERROR SHCRaftConsensus".
File corruption in a member's
_raft folder is a common cause of Raft issues. You can fix the problem by cleaning the folder on the member. The folder then repopulates from the captain.
To fix a Raft issue, clean the member's
_raft folder. Run the
splunk clean raft command on the member:
Stop the member:
Clean the member's raft folder:
splunk clean raft
Start the member:
_raft folder will be repopulated from the captain.
Fix the entire cluster
If captain election fails even though a majority of members are available, raft metadata corruption is a likely cause. To confirm, you can examine the members'
splunkd.log files for errors that start with the string "ERROR SHCRaftConsensus".
You can resolve the issue by cleaning the folder on all members and then bootstrapping the cluster:
- Stop all members.
splunk clean rafton each member:
splunk clean raft
- Start all members.
Select one member to be captain and bootstrap it:
splunk bootstrap shcluster-captain -servers_list "<URI>:<management_port>,<URI>:<management_port>,..." -auth <username>:<password>
- If you are using search peer replication, you must re-add the search peers to one member. See Replicate the search peers across the cluster.
Overview of search head pooling
This documentation applies to the following versions of Splunk® Enterprise: 6.5.0, 6.5.1, 6.5.1612 (Splunk Cloud only), 6.5.2, 6.5.3, 6.5.4, 6.5.5, 6.5.6, 6.6.0, 6.6.1, 6.6.2, 6.6.3, 6.6.4, 7.0.0, 7.0.1