Splunk Interview Questions

Splunk collects valuable machine data from servers, applications, databases, networks, and other data sources. It then transforms the data into powerful operational intelligence by providing real-time insights through charts, alerts, and reports.

The table shows the differences between Splunk and Hadoop.

The table below shows the common port numbers.

Below are the components of the Splunk Architecture

• Search Head: It provides a GUI for searching
• Indexer: It indexes machine data
• Forwarder: It forwards logs to the Indexer
• Deployment Server: It manages Splunk components in a distributed environment.

The latest Splunk version is Splunk Enterprise 10.4.1 as of July 2026.

Here are the key features:

• Federated Search
• Configuration Validation
• Enhanced Dashboard Studio
• Improvements in the Edge Processor
• Enhanced SPL2 Support
• Enterprise-Level Data Management

The table below shows the differences between Splunk and Logstash.

The table below compares Splunk with Sumo Logic.

The following are the different stages in Splunk indexing:

• Input Phase
• Parsing Phase
• Indexing Phase
• Search Phase

The primary functions of an indexer are listed below:

• Indexing incoming data
• Searching the indexed data

SPL2 offers a more structured, SQL-like syntax. It also simplifies searches, making them easier to read, write, maintain, and integrate across modern Splunk products.

A Splunk source type helps parse, format, and search incoming data accurately. The following are some of the common Splunk source types:

• syslog
• WinEventLog: Security
• apache:access
• cisco:asa
• json

A Splunk Forwarder securely transfers this data to a Splunk deployment for indexing and analysis. It ensures reliable log forwarding and supports encrypted communication (SSL/TLS). Moreover, it reduces network bandwidth through data compression.

Google introduced the MapReduce algorithm; however, it later became the main processing framework for Apache Hadoop. This algorithm breaks a large job into smaller tasks, processes them concurrently, and then merges the results.

• Universal Forwarder (UF) – A Splunk agent installed on a non-Splunk system to collect data locally.
• Heavy Forwarder (HF) – A full Splunk instance with advanced functionality serves as a remote collector, intermediate forwarder, and potential data filter.

The following are the important configuration files in Splunk.

• props.conf
• indexes.conf
• inputs.conf
• transforms.conf
• server.conf

Splunk Dashboard Studio allows users to build visually appealing dashboards without complex backend coding. It uses JSON, whereas the classic dashboard editor uses XML.

Splunk AI Assistant helps you create, understand, and improve Search Processing Language (SPL) queries using natural language. You can describe what you want to analyze rather than manually write complex searches. The assistant generates the necessary SPL based on your description.

It uses AI agents to understand context, investigate issues, and recommend actions. You can use the AI agents to reduce mundane manual tasks, speed up incident response, and enhance operational efficiency.

RAG fetches relevant enterprise data from Splunk before generating a response. It triggers responses using real-time operational data, including logs, metrics, traces, alerts, dashboards, and knowledge objects, instead of relying solely on the model's pre-trained knowledge.

The Splunk licenses are listed below:

• Enterprise License 
• Free License 
• Trial License 
• Forwarder License 
• Developer License

A Fishbucket doesn't store searchable event data, unlike normal indexes. However, it stores metadata including file signatures and read offsets. Its main purpose is to stop duplicate indexing and help Splunk resume reading from the right position after a restart.

Splunk Apps can be used for monitoring security, compliance, and IT operations. You can install Splunk apps on Splunk Enterprise or the Splunk Cloud Platform.

Below are some of the Splunk Apps:

• Splunk Enterprise Security (ES)
• Splunk IT Service Intelligence (ITSI)
• Splunk App for AWS
• Splunk App for Windows

You can use the command below for the same.

$SPLUNK_HOME/etc/system/default/

Splunk Free version lacks the following features:

• Authentication and scheduled searches/alerting
• Distributed search
• Forwarding in TCP/HTTP
• Deployment management

You can use the Splunk Edge Processor to filter, transform, mask, and route data before it reaches Splunk Cloud or Splunk Enterprise. The processor helps reduce ingestion costs, improve data quality, and protect sensitive information at the edge.

A Heavy Forwarder (HF) is a full Splunk Enterprise instance that you can use for more advanced data collection, parsing, optional indexing, and forwarding.

A summary index helps improve dashboard performance by preventing repeated searches across large volumes of historical data. If you plan to run a variety of summary index reports, you may need to create additional summary indexes.

You can use Splunk DBX to import data from databases into Splunk and export Splunk search results into databases. The important thing is that you must develop custom scripts to perform the import and export actions.

Splunk DBX uses a JDBC driver to connect Splunk to databases.

Yes, you can write a general regular expression to extract IP addresses from logs.

Below is the commonly used regular expression for matching IPv4 addresses in Splunk logs:

\b( ?: 25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)( ?: \.( ?: 25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)){3}\b

You can use the stats command for quick aggregation and summarization. On the other hand, you can use the transaction command to group related events into a single transaction.

The output of the stats command is a summary table, whereas the output of the transaction command is a combined list of transaction events.

A bucket moves through several stages as shown below:

• Hot: This stage has the newly indexed data. One or more hot buckets are required for each index.
• Warm: It has the data rolled from hot. There are many warm buckets.
• Cold: It has the data rolled from warm. There are many cold buckets.
• Frozen: It has data rolled from cold. The indexer deletes frozen data by default, but you can also archive it.

By default, your buckets are located in:

$SPLUNK_HOME/var/lib/Splunk/default/db.

By default, Splunk sets the bucket size to 10GB for 64-bit systems and 750MB for 32-bit systems.

RBA accumulates risk over time and triggers an alert only when the total risk exceeds a set threshold, instead of sending a high-priority alert for each event. This method helps IT security teams focus on the most serious threats and lowers alert fatigue.

Splunk stats command generates summary statistics of all existing fields in your search results and stores them as values in new fields. The eventstats command is similar to the stats command, except that aggregation results are added inline to each event only if the aggregation is pertinent to that event.

eventstats computes statistics like the stats command, but aggregates them to the original raw data.

Basically, both contain preconfigured settings and reports, etc. However, the Splunk add-on does not have a visual app. At the same time, Splunk apps have preconfigured visual components.

The following are the direct competitors to Splunk.

• Logstash
• Loggly
• LogLogic
• Sumo Logic

File precedence is as follows:

• System local directory — highest priority
• App local directories
• App default directories
• System default directory — lowest priority.

Splunk licenses specify how much data you can index per calendar day.

Splunk determines one day as from midnight to midnight on the License Master's clock.

Forwarder licenses are included with the Splunk license. You don’t need to purchase them separately.

Splunk SDKs are designed to allow you to develop applications from the ground up and not require Splunk Web or any components from the Splunk App Framework. These are separately licensed to you from Splunk Software and do not alter the Splunk Software.

Splunk App Framework resides within Splunk’s web server and permits you to customize the Splunk Web UI that comes with the product and develop Splunk apps using the Splunk web server. It is an important part of the features and functionality of Splunk Software, and Splunk does not license users to modify it.

Search Head clustering ensures high availability, scalability, and centralized management across multiple Search Heads. Besides, it ensures continuous search capabilities, even if one search head fails.

Importantly, Search Head clustering secures the search layer, whereas indexer clustering protects indexed data.

Splunk ITSI identifies gradual changes from normal operating patterns. Unlike traditional monitoring that depends on fixed thresholds, Drift Detection detects gradual shifts that indicate potential performance issues before they become serious incidents.

ESCU assists Security Operations Center (SOC) teams in detecting, investigating, and responding to cyber threats without the need to create detection rules from scratch.

Generally, the Splunk Threat Research Team (STRT) maintains ESCU. They update it regularly with new detections based on modern attack methods and threat intelligence.

The Federal Risk and Authorization Management Program (FedRAMP) is a U.S. government program. It sets a standard for the security assessment, authorization, and monitoring of cloud services. 

A FedRAMP Moderate authorization indicates that the platform meets the security controls required for systems that manage moderate-impact federal information. These requirements are based on NIST SP 800-53 security controls.

The dispatch directory is located at $SPLUNK_HOME/var/run/Splunk/dispatch/, and it contains a directory for each search that is running or has completed.

For example, a directory named 1434308943.358 will contain a CSV file of its search results, a search.log with details about the search execution, and other files.

Using the defaults (which you can override in limits.conf), these directories will be deleted ten minutes after the search completes, unless the user saves the search results.

FBD allows Splunk ES to aggregate related security observations into high-confidence incidents. Moreover, FBD collects multiple related findings for the same entity, such as a user or host. This approach makes security investigations more efficient.

Since the acquisition, Splunk has increasingly aligned with Cisco’s vision to provide enhanced IT security, observability, and networking.

After the Cisco integration, Splunk seamlessly integrates with third-party systems and the Cisco ecosystem. It allows organizations to detect and respond to threats across various IT environments. Besides, it ensures enhanced troubleshooting and network monitoring.    

Below is the command for the same.

splunk restart

splunk start

splunk stop

splunk restart splunkweb

We can use the command below.

Splunk start

Below is the command:

ps aux | grep splunk

Below is the command:

$SPLUNK_HOME/bin/splunk enable boot-start

Below is the command:

$SPLUNK_HOME/bin/splunk disable boot-start

We can follow the procedure below to reset the Splunk admin password.

1. Log in to the server on which Splunk is installed
2. Rename the password file at the location below
3. Restart Splunk
4. After the restart, you can log in using the default username: admin and password: changeme.

Some of the troubleshooting methods are listed below:

1. First, identify the problem
2. Examine the system resources
3. Review the Splunk monitoring console
4. Verify internal logs
5. List Slow Searches

We can use the command below:

splunk start -- no-prompt

We must delete the following file on the Splunk server.

$splunk_home/var/log/splunk/searches.log

Splunk btool is a command-line tool that helps troubleshoot configuration file issues. We can use this tool to check what values are being used by your Splunk Enterprise installation in the existing environment.

We can do this by defining a regex to match the required event(s) and routing everything else to the null queue.

Here is a basic example that will drop everything except events whose props contain the string "login". Conf:

-----------------------------
[ source: : /var/log/foo]
# Transforms must be applied in this order
# to make sure events are dropped on the
# floor prior to making their way to the
# index processor

TRANSFORMS-set= setnull, setparsing
--------------------------------------------
In transforms.conf
----------------------------------------------
[setnull] REGEX = . DEST_KEY = queue FORMAT = nullQueue

[setparsing]
REGEX = login
DEST_KEY = queue
FORMAT = indexQueue
-----------------------------------------------------

By monitoring data from Splunk's metrics log in real time.

index="_internal" source="*metrics.log" group="per_sourcetype_thruput" series="" | eval MB=kb/1024 | chart sum(MB)

1. Enable Object Access Audit through group policy on a Windows machine on which the folder is located
2. Enable auditing on the specific folder for which you want to monitor logs
3. Install the Splunk Universal Forwarder on a Windows machine
4. Configure the Universal Forwarder to send security logs to the Splunk indexer.

A license violation warning means Splunk has indexed more data than the licensed daily indexing quota.

• We must identify which index or source type has received more data recently than the normal daily data volume.
• We can examine the Splunk License Master pool-wise available quota and identify the pool where the violation is occurring.
• Once we know which pool we are receiving more data from, we must identify the top source type that is receiving more data than normal.
• Once the source type is identified, we must find the source machine sending a large volume of logs, identify the root cause, and troubleshoot accordingly.

Yes, you can learn Splunk easily. If you have a basic understanding of cloud computing and data monitoring, learning Splunk will be seamless.

Splunk IT Service Intelligence (ITSI) is an advanced application for Splunk. It helps IT Operations (ITOps), Site Reliability Engineering (SRE), and Network Operations Center (NOC) teams to monitor and improve the performance of business services.

Splunk Enterprise is self-managed. You can install, configure, upgrade, secure, and maintain the Splunk deployment.

On the other hand, Splunk Cloud Platform is a fully managed SaaS offering in which Splunk (Cisco) manages the underlying platform. Customers manage their data, users, searches, dashboards, and applications within the supported framework.