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Splunk Interview Questions

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by Madhuri Yerukala
Last modified: July 19th 2021

If you're looking for Splunk Interview Questions & Answers for Experienced or Freshers, you are at the right place. There are a lot of opportunities from many reputed companies in the world. According to research, Splunk has a market share of about 36.2%. So, You still have the opportunity to move ahead in your career in Splunk. Mindmajix offers Advanced Splunk Interview Questions 2021 that helps you in cracking your interview & acquire your dream career as Splunk Developer.

Types of Splunk Interview Questions

Top 10 Frequently Asked Splunk Interview Questions in 2021

  1. What is Splunk?
  2. What are the common port numbers used by Splunk?
  3. What are the components of Splunk/Splunk architecture?
  4. What is Splunk indexer? What are the stages of Splunk indexing?
  5. What are the types of Splunk licenses?
  6. What is the Splunk app?
  7. Where Splunk's default configuration does is stored?
  8. what is the summary index in Splunk?
  9. What is Splunk DB connect?
  10. What are buckets? Explain Splunk bucket lifecycle?
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Q) Splunk Vs ELK

Compare Splunk and Elastic Stack
Feature Splunk ELK
Log Management Highly supported Highly supported
Customizations Available Available
Advanced reporting Available Available
Robust Search Capable of robust search Capable of robust search
Deployment steps Easy to deploy Easy to deploy
Dashboard features Offers more features than ELK Relatively less when compared to Splunk
Community support Highly professional community to support Open Source has more benefits due to huge user base
Latest Version Splunk 6.5 Elastic Stack 5.0
Pricing Offers enterprise editions Open Source
APIs supported/built on RESTful API and 200 plus endpoints RESTFul API and JSON
Third-party integrations App portal provides 1000s of add-ons Plethora of integrations and plugins

Basic Splunk Interview Questions and Answers

1) What is Splunk?

Splunk is Google for your machine data. It’s a software/Engine which can be used for searching, visualizing, Monitoring, reporting etc of your enterprise data. Plunk takes valuable machine data and turns it into powerful operational intelligence by providing real-time insight to your data through charts, alerts, and reports, etc.

2) Difference between Splunk and Hadoop

Splunk Cloud Hadoop HDFS
Annual Subscription Free
Cloud-based service Distributed file system designed to run on commodity hardware
Splunk is a tool Hadoop is a framework
Collect and Index Data File System Namespace
 Splunk is a log analysis platform Hadoop is a BigData file system
Devices Supported: Windows, Android, iPhone/iPad, Mac Devices Supported: Windows, Mac
Web-based
Splunk DB Connect Browser Interface
Splunk App for Stream DFSAdmin
Splunk mainly monitors, log, and analyze machine-generated big data. Hadoop is ideal for ETL and storage of data in HDFS and streamlining analysis 
Splunk is an integrated solution for data analysis Hadoop is an implementation of the Map-Reduce paradigm 

3) What are the common port numbers used by Splunk?

Below are common port numbers used by Splunk, however, you can change them if required

Service                                    Port number Used
Splunk Web Port 8000
Splunk Management Port 8089
Splunk Indexing Port 9997
Splunk Index Replication Port 8080
Splunk network port 514 (Used to get data in from network port i.e. UDP data)
KV store 8191

4) What are the components of Splunk/Splunk architecture?

Below are components of Splunk architecture

  • Search head: provides GUI for searching
  • Indexer: indexes machine data
  • Forwarder: Forwards logs to Indexer
  • Deployment server: Mange’s Splunk components in a distributed environment

5) Which is the latest Splunk version in use?

Latest Version Release - Splunk 6.3

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6) Compare Splunk VS Logstash Vs Sumo Logic:

Splunk Logstash Sumo Logic
A big player in the log management tool space An open-source log management tool SaaS version of Splunk
On-Premises Model SaaS Used as part of the ELK stack along with ElasticSearch and Kibana
Installation: Setting it up locally Installation: Setting up a communication out to the Sumo Logic cloud Installation: Setting it all up on your own system
Need to plan for the hardware and space capacities that you will need. Need to configure the sources that will gather and send the logs to Sumo Logic Need to configure the inputs, filters, and outputs that you’ll want
An extensive amount of features are available Has a good chunk of similar features to Splunk Logstash gives you the most control over the tools between devloepment & Community
Can create and manage your own dashboards Uses a panel-based dashboard system On its own, Logstash doesn’t give you dashboards at all
Dashboards can be built in either XML code or through the Splunk dashboard editor Most of the information is presented in a chart-based manner As part of the ELK stack, Kibana is used as frontend reporting & visualization, metrics tools, such as Graphite, Librato, and DataDog.
600+ Integration Plugins available Includes development automation tools, cloud platforms, OS platforms, and compliance and security tools Logstash has a continuously growing plugin environment, over 160 plugins available
Pricing - $1800 – $60,000 per year Pricing - Free lite version, Entry-level pricing is friendlier Pricing - Free, avail paid subscriptions also

7) What is a Splunk indexer? What are the stages of Splunk indexing?

The indexer is the Splunk Enterprise component that creates and manages indexes. The primary functions of an indexer are:

  • Indexing incoming data.
  • Searching the indexed data.

8) What is a Splunk forwarder and what are the types of Splunk forwarder?

There are two types of Splunk forwarder as below

  1. Universal forwarder (UF) -Splunk agent installed on the non-Splunk system to gather data locally, can’t parse or index data.
  2. Heavyweight forwarder (HWF) – a full instance of Splunk with advanced functionality generally works as a remote collector, intermediate forwarder, and possible data filter because they parse data, they are not recommended for production systems

9) what are the most important configuration files of Splunk OR can you tell the names of few important configuration files in Splunk?

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

10) What are the types of Splunk licenses?

  • Enterprise license
  • free license
  • Forwarder license
  • Beta license
  • Licenses for search heads (for distributed search)
  • Licenses for cluster members (for index replication)
Check Out here for Splunk Tutorials 

11) What is the Splunk app?

Splunk app is container/directory of configurations, searches, dashboards, etc in Splunk

12) Where Splunk default configuration does is stored?

$splunkhome/etc/system/default

13) What features are not available in Splunk free?

Splunk free lacks these features:

  • authentication and scheduled searches/alerting
  • distributed search
  • forwarding in TCP/HTTP (to non-Splunk)
  • deployment management

14) What happens if the license master is unreachable? 

License slave will start a 24-hour timer, after which search will be blocked on the license slave (though indexing continues). Users will not be able to search data in that slave until it can reach license master again

15) what is a summary index in Splunk?

The Summary index is the default summary index (the index that Splunk Enterprise uses if you do not indicate another one). If you plan to run a variety of summary index reports you may need to create additional summary indexes.

 

Splunk Architect Interview Questions and Answers

16) What is Splunk DB connect?

Splunk DB Connect is a generic SQL database plugin for Splunk that allows you to easily integrate database information with Splunk queries and reports.

17) Can you write down a general regular expression for extracting ip address from logs?

There are multiple ways we can extract IP addresses from logs. Below are few examples.
Regular Expression for extracting IP address:
Expression for extracting IP address

18) What is the difference between stats vs transaction command?

The transaction command is most useful in two specific cases:

Unique id (from one or more fields) alone is not sufficient to discriminate between two transactions. This is the case when the identifier is reused, for example, web sessions identified by cookie/client IP. In this case, time span or pauses are also used to segment the data into transactions. In other cases when an identifier is reused, say in DHCP logs, a particular message may identify the beginning or end of a transaction.

When it is desirable to see the raw text of the events combined rather than analysis on the constituent fields of the events.

In other cases, it’s usually better to use stats as the performance is higher, especially in a distributed search environment. Often there is a unique id and stats can be used.

19) How to troubleshoot Splunk performance issues?

The answer to this question would be very wide but basically, interviewer would be looking for the following keywords in an interview:

  • Check splunkd.log for any errors
  • Check server performance issues i.e. CPU/memory usage, disk i/o, etc
  • Install SOS (Splunk on Splunk) app and check for warning and errors in the dashboard
  • Check the number of saved searches currently running and their system resources consumption
  • Install Firebug, which is a firefox extension. After it’s installed and enabled, log into Splunk (using firefox), open firebug’s panels, switch to the ‘Net’ panel (you will have to enable it). The Net panel will show you the HTTP requests and responses along with the time spent in each. This will give you a lot of information quickly over which requests are hanging Splunk for a few seconds, and which are blameless. etc..

20) What are the buckets? Explain Splunk bucket lifecycle?

Splunk places indexed data in directories, called as “buckets”. It is physically a directory containing events of a certain period. A bucket moves through several stages as it ages:

  • Hot: Contains newly indexed data. Open for writing. One or more hot buckets for each index.
  • Warm: Data rolled from hot. There are many warm buckets.
  • Colld: Data rolled from warm. There are many cold buckets.
  • Frozen: Data rolled from cold. The indexer deletes frozen data by default, but you can also archive it. Archived data can later be thawed (Data in frozen buckets is not searchable)

By default, your buckets are located in $SPLUNK_HOME/var/lib/Splunk/default/db. You should see the hot-db there, and any warm buckets you have. By default, Splunk sets the bucket size to 10GB for 64bit systems and 750MB on 32bit systems.

21) What is the difference between stats and event stats commands?

Stats command generates summary statistics of all existing fields in your search results and saves them as values in new fields. Eventstats is similar to the stats command, except that aggregation results are added inline to each event and only if the aggregation is pertinent to that event.
event stats computes the requested statistics like stats but aggregates them to the original raw data.

22) Who are the biggest direct competitors to Splunk?

logstash, Loggly, LogLogic, sumo logic, etc..

23) Splunk licenses specify what?

How much data you can index per calendar day 

24) How does Splunk determine 1 day, from a licensing perspective?

Midnight to midnight on the clock of the license master

25) How are forwarder licenses purchased?

They are included with Splunk, no need to purchase separately

26) What is a command for restarting just the Splunk web server?

Splunk start Splunk web

27) What is a command for restarting just the Splunk daemon?

Splunk start Splunk

28) What is the command to check for running Splunk processes on Unix/Linux?

ps aux | grep Splunk

29) What is Command to enable Splunk to boot start?

$SPLUNK_HOME/bin/Splunk enable boot-start

30 How to disable Splunk boot start?

$SPLUNK_HOME/bin/Splunk disable boot-start

Learn Splunk Eval Commands With Examples

Splunk Scenario Based Interview Questions

31) What is the source type in Splunk?

The source type is Splunk way of identifying data

32) How to reset Splunk admin password?

o reset your password log in to the server on which Splunk is installed and rename passwd file at the below location and then restart Splunk. After restart, you can log in using default username: admin password:changeme
Password reset 

33) How to disable Splunk launch message?

Set value OFFENSIVE=Less in splunk_launch.conf

34) How to clear Splunk search history?

Delete the following file on Splunk server

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

35) What is btool or how will you troubleshoot Splunk configuration files?

Splunk btool is a command-line tool that helps us to troubleshoot configuration file issues or just see what values are being used by your Splunk Enterprise installation in the existing environment.

Related Article: Splunk Tool 

36) What is the difference between the Splunk app and Splunk add-on?

Basically, both contains preconfigured configuration and reports etc, but the Splunk add-on does not have a visual app. Splunk apps have preconfigured visual app.

37) What is .conf files precedence in Splunk?

File precedence is as follows:

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

38) What is a fish bucket or what is a fish bucket index?

It’s a directory or index at default location /opt/Splunk/var/lib/Splunk .It contains seek pointers and CRCs for the files you are indexing, so splunkd can tell if it has read them already. We can access it through GUI by searching for  “index=_thefishbucket”

39) How do I exclude some events from being indexed by Splunk?

This can be done by defining a regex to match the necessary event(s) and send everything else to the null queue. Here is a basic example that will drop everything except events that contain the string login In props. 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
—————————————————————————————

 

40) How can I tell when Splunk is finished indexing a log file?

By watching 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)

or to watch everything happening split by source type….

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

And if you’re having trouble with data input and you want a way to troubleshoot it, particularly if your whitelist/blacklist rules aren't working the way you expect, go to this URL: HTTPS://YOURSPLUNKHOST:8089/SERVICES/ADMIN/INPUTSTATUS

41) How to set the default search time in Splunk 6?

To do this in Splunk Enterprise 6.0, use ui-prefs.conf. If you set the value in $SPLUNK_HOME/etc/system/local, all your users should see it as the default setting. For example, if your $SPLUNK_HOME/etc/system/local/ui-prefs.conf file includes:

[search]
dispatch.earliest_time = @d
dispatch.latest_time = now

The default time range that all users will see in the search app will be today.
The configuration file reference for ui-prefs.conf is here: HTTP://DOCS.SPLUNK.COM/DOCUMENTATION/SPLUNK/LATEST/ADMIN/UI-PREFSCONF

42) What is the dispatch directory?

$SPLUNK_HOME/var/run/Splunk/dispatch 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 stuff. Using the defaults (which you can override in limits.conf), these directories will be deleted 10 minutes after the search complfetes – unless the user saves the search results, in which case the results will be deleted after 7 days.

43) What is the difference between search head pooling and search head clustering?

Both are features provided by Splunk for the high availability of Splunk search head in case anyone's search head goes down. Search head cluster is newly introduced and search head pooling will be removed in next upcoming versions. Search head cluster is managed by the captain and the captain controls its slaves. Search head cluster is more reliable and efficient than search head pooling.

44) If I want to add/onboard folder access logs from a windows machine to Splunk how can I add the same?

Below are steps to add folder access logs to Splunk

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

45) How would you handle/troubleshoot Splunk license violation warning error?

License violation warning means Splunk has indexed more data than our purchased license quota. We have to identify which index/source type has received more data recently than the usual daily data volume. We can check on Splunk license master pool-wise available quota and identify the pool for which violation is occurring. Once we know the pool for which we are receiving more data then we have to identify top source type for which we are receiving more data than usual data. Once the source type is identified then we have to find outsource machine which is sending a huge number of logs and root cause for the same and troubleshoot accordingly.

46) What is the MapReduce algorithm?

MapReduce algorithm is the secret behind Splunk's fast data searching speed. It’s an algorithm typically used for batch-based large-scale parallelization. It’s inspired by functional programming’s map() and reduce () functions.

47) How Splunk avoids duplicate indexing of logs?

At indexer, Splunk keeps track of indexed events in a directory called fish buckets (default location /opt/Splunk/var/lib/Splunk). It contains seek pointers and CRCs for the files you are indexing, so splunkd can tell if it has read them already. – See more at: https://www.learnsplunk.com/splunk-indexer-configuration.html#sthash.t1ixi19P.dpuf.

48) What is the difference between Splunk SDK and Splunk framework?

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 the 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 functionalities of Splunk Software, which does not license users to modify anything in the Splunk Software.

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About Author

author
NameMadhuri Yerukala
Author Bio

Madhuri is a Senior Content Creator at MindMajix. She has written about a range of different topics on various technologies, which include, Splunk, Tensorflow, Selenium, and CEH. She spends most of her time researching on technology, and startups. Connect with her via LinkedIn and Twitter .