License master and cluster master

You can create a license master, which is a centralized license server for the entire deployment, simply by installing the Splunk Enterprise license you obtained from Splunk sales on it:

1. (Splunk Web)(license master): Settings | Licensing | Add new license | Choose File | Install
2. Click the provided button to restart Splunk

After logging back in, navigate to Settings | Licensing and verify the license was installed. You'll also note at the top of this page that This server is acting as a master license server – so there's nothing else to do in terms of configuring a license master. During this operation, the license file you imported was saved in /opt/splunk/etc/licenses/.

To enable this node as a cluster master, perform the following steps in Splunk Web:

• Settings | Indexer clustering —click Enable indexer clustering
• Select Master node (default) and click Next
• Set the replication factor to 2 and leave the search factor at 2 (or the RF/SF of your choice)
• Enter !Sp1unkCM! in the Security Key field (or a security key of your choice)
• Enter DevTestIndexers in the Cluster Label field (or an entry of your choice)
• Click Enable Master Node and Restart Now

When the server comes back up, you can view the /opt/splunk/etc/system/local/
server.conf file and note the following settings that weren't there before; in most cases, you can tell what function a Splunk server is performing just by inspecting the server.conf file. The [lmpool:...] and [license] stanzas reflect the default license pool settings and the fact that you're using a Splunk Enterprise license; the [clustering] stanza reflects the choices made for clustering. Note that the pass4SymmKey 
contains an obfuscated version of the security key you entered (!Sp1unkCM!) during setup; Splunk does this to all plain text security keys upon startup:

[lmpool:auto_generated_pool_enterprise]
description = auto_generated_pool_enterprise
quota = MAX
slaves = *
stack_id = enterprise

[license]
active_group = Enterprise

[clustering]
cluster_label = DevTestIndexers
mode = master
pass4SymmKey = $1$J2nsIHghS61r0NU=
replication_factor = 2