Enable the search head

Before reading this topic, read "Indexer cluster deployment overview".

To search the cluster, you need to enable at least one search head in the indexer cluster.

Before enabling the search head, you must enable and restart the master node, as described in "Enable the master node".

The procedure in this topic explains how to use Splunk Web to enable a search head. You can also enable a search head in two other ways:

• Directly edit the search head's server.conf file. See "Configure the search head with server.conf" for details. Some advanced settings, including multi-cluster search, can only be configured by editing this file.
• Use the CLI edit cluster-config command. See "Configure the search head with the CLI" for details.

Important: This topic explains how to enable an individual search head for a single-site cluster only:

• If you plan to deploy a multisite cluster, see "Configure multisite indexer clusters with server.conf".

• If you plan to incorporate search heads that are members of a search head cluster, see "Integrate the search head cluster with an indexer cluster" in the Distributed Search manual.

Enable the search head

To enable a Splunk instance as a search head in an indexer cluster:

1. Click Settings in the upper right corner of Splunk Web.

2. In the Distributed environment group, click Indexer clustering.

3. Select Enable clustering.

4. Select Search head node and click Next.

5. There are a few fields to fill out:

• Master URI. Enter the master's URI, including its management port. For example: https://10.152.31.202:8089.
• Security key. This is the key that authenticates communication between the master and the peers and search heads. The key must be the same across all cluster nodes. Set the same value here that you previously set on the master node.

6. Click Enable search head node.

The message appears, "You must restart Splunk for the search node to become active. You can restart Splunk from Server Controls."

7. Click Go to Server Controls. This takes you to the Settings page where you can initiate the restart.

Next steps

Now that you have enabled the search head, you can:

• View the search head dashboard
• Allow the search head to search other clusters
• Add search heads to the cluster
• Perform additional configuration on the search head

View the search head dashboard

After the restart, log back into the search head and return to the Clustering page in Splunk Web. This time, you see the search head's clustering dashboard. See "View the search head dashboard" for more information.

Allow the search head to search multiple clusters

From the dashboard, you can add additional clusters for the search head to search. For details, see "Search across multiple indexer clusters".

Add search heads to an indexer cluster

You can set up multiple search heads to accommodate more simultaneous searches. For information on how to determine your search head needs, see "Hardware capacity planning" in the Capacity Planning manual.

If you want to set up more search heads for an indexer cluster, just repeat the enablement procedure for additional instances. If you want to deploy a search head cluster, so that the search heads share configurations and jobs, see the additional configuration instructions in the topic "Integrate the search head cluster with an indexer cluster" in the Distributed Search manual.

Perform additional configuration

For more information on configuration of search heads in an indexer cluster, see "Search head configuration overview".