Install Splunk in multi-instance mode

This document will guide you through the installation process for a multi-instance distributed architecture, recommended for larger environments with huge amounts of data (in this case, Wazuh alerts) and users.

Note

Many of the commands described below need to be executed with root user privileges.

We’re going to perform the most basic installation for a multi-instance deployment. We’ll use two instances of Splunk Enterprise, one of them being the search head and the other one, a search peer (commonly known as an indexer); we’ll also need a Splunk forwarder.

  • The search head instance will be in charge of all the searching functionality, and it will look for data on the search peers’ indexes. This instance won’t have any indexes at all.
  • The search peer instance (or indexer) collects all the Wazuh data and stores it in the form of indexes. This instance is connected to the search head so it can consult the peer’s indexes.
  • The forwarder runs on the Wazuh manager instance, it reads local data and sends it to the indexer.

You can have multiple search peer instances, but in this case we’re going to stick with the essentials.

Warning

This documentation will install Splunk using the multi-instance deployment schema. If you want a simpler installation, check out the single-instance deployment schema.

Install Splunk Enterprise instances

Each instance can be installed on different hosts following the same steps described below:

  1. Download Splunk v7.2.4 package from its official website.

Note

Splunk is not open source software and it requires a registered user and license in order to work. You can also use a free trial license.

  1. Install the Splunk v7.2.4 package:
  1. For RPM based distributions:
# yum install splunk-enterprise-package.rpm
  1. For Debian/Ubuntu distributions:
# dpkg --install splunk-enterprise-package.deb
  1. Ensure Splunk v7.2.4 is installed in /opt/splunk and start the service:
# /opt/splunk/bin/splunk start

Note

You will be prompted for a name and password for the administrator user.

After this step the Splunk Web service will be listening to port 8000. You can browse http://<your-instance-ip>:8000 in order to access the Web GUI.

  1. Optional. If you additionally want the Splunk service to start at boot time, please execute the following command:
# /opt/splunk/bin/splunk enable boot-start

Configuring the Splunk instances

Now that we finished installing the Splunk instances, it’s time to choose which one will be the search head and the search peer.

  1. On the search head instance run the following command to add a search peer:
# /opt/splunk/bin/splunk add search-server <host>:<port> -auth <user>:<password> -remoteUsername <user> -remotePassword <passremote>

You must run this command for each search peer that you want to add.

Note the following:

  1. <host> is the host name or IP address of the search peer’s host machine.
  2. <port> is the management port of the search peer. By default it’s 8089.
  3. The -auth flag is used to provide credentials for the search head.
  4. The -remoteUsername and remotePassword flags are used to provide the credentials for the search peer. The remote credentials must be for an admin-level user on the search peer.

Warning

If there are login issues when trying to add the search peer, add the allowRemoteLogin = always option under the [general] section on the /opt/splunk/etc/system/local/server.conf file, and then restart the search peer.

  1. On the search peer instance we need to add the files to configure the Wazuh indexes:
  1. Download and insert the inputs.conf template to configure where the data will come from:
# curl -so /opt/splunk/etc/system/local/inputs.conf https://raw.githubusercontent.com/wazuh/wazuh/3.8/extensions/splunk/peer-inputs.conf
  1. Download and insert the indexes.conf template to configure the indexes:
# curl -so /opt/splunk/etc/system/local/indexes.conf https://raw.githubusercontent.com/wazuh/wazuh/3.8/extensions/splunk/peer-indexes.conf

And finally, we need to restart the search peer:

# /opt/splunk/bin/splunk restart

Now that you’ve finished installing Splunk on a multi-instance mode, you can proceed with the next step and install the Wazuh app for Splunk.