What are the three main components of Splunk?

Splunk's architecture is built around three main components: Forwarder, Indexer, and Search Head. These components work together to collect, process, and analyze data effectively.

Simplified real-world example

Imagine running a delivery service with thousands of trucks sending data (like location, speed, and engine status) to a central system. Splunk’s components would work like this:

1. Forwarder: Trucks send their data to a central Splunk server.
2. Indexer: The central server organizes and stores the data for quick access.
3. Search Head: You search and visualize the data to spot trends or problems, like delivery delays or engine failures.

Key components of Splunk

1. Forwarder

The Forwarder collects data from various sources (servers, apps, devices) and sends it to the Indexer. There are two types:

• Universal Forwarder: Lightweight and only forwards raw data.
• Heavy Forwarder: Can preprocess data before sending it.

Use case

A Forwarder on a web server collects logs like errors or access requests and streams them to the Indexer for analysis.

2. Indexer

The Indexer processes the incoming data, organizes it into an efficient format, and stores it. It makes the data searchable, ensuring fast query performance.

Key tasks:

• Indexing raw data into events.
• Storing indexed data for real-time and historical searches.

Use case

The Indexer stores web server logs, making it possible to search for all 404 errors in the past 24 hours instantly.

3. Search Head

The Search Head is the user interface where you run queries, create dashboards, and visualize data. It communicates with the Indexer to fetch and display the required results.

Features:

• Search and query data using Splunk Processing Language (SPL).
• Create interactive dashboards and reports.

Use case

A Search Head lets you query “Top 10 pages with the most visits today” and view results as a chart in seconds.

Learn more about Splunk architecture

To understand how Splunk fits into system design, consider Grokking System Design Fundamentals for a beginner-friendly approach. For more advanced concepts, explore the System Design Primer to enhance your knowledge. These resources will solidify your understanding of Splunk’s architecture and use cases.