Splunk® Enterprise

Capacity Planning Manual

Download manual as PDF

Download topic as PDF

How search types affect Splunk Enterprise performance

You can invoke four types of searches against data stored in a Splunk Enterprise index. Each search type impacts the indexer in a different way.

The following table summarizes the different search types. For dense and sparse searches, Splunk Enterprise measures performance based on number of matching events. With super-sparse and rare searches, performance is measured based on total indexed volume.

Search type Description Ref. indexer throughput Performance impact
Dense Returns a large percentage (10% or more) of matching results for a given set of data in a given period of time. Dense searches usually tax a server's CPU first, because of the overhead required to decompress the raw data stored in a Splunk Enterprise index. Examples of dense searches include searches that use nothing but a wildcard character, or searching any index.



index=m …| stats count by fieldA

index=a sourcetype=b …| timechart count by myfield
Up to 50,000 matching events per second. CPU-bound
Sparse Returns a smaller amount of results for a given set of data in a given period of time (anywhere from .01 to 1%) than do dense searches. Up to 5,000 matching events per second. CPU-bound
Super-sparse Returns a small number of results from each index bucket that matches the search. A super-sparse search is I/O intensive because the indexer must look through all of the buckets of an index to find the results. If you have a large amount of data stored on your indexer, there are a lot of buckets, and a super-sparse search can take a long time to finish. Up to 2 seconds per index bucket. I/O bound
Rare Similar to a super-sparse search, but receives assistance from bloom filters, which help eliminate index buckets that do not match the search request. Rare searches return results anywhere from 20 to 100 times faster than does a super-sparse search. From 10 to 50 index buckets per second. I/O bound
How saved searches / reports affect Splunk Enterprise performance
How Splunk apps affect Splunk Enterprise performance

This documentation applies to the following versions of Splunk® Enterprise: 6.2.0, 6.2.1, 6.2.2, 6.2.3, 6.2.4, 6.2.5, 6.2.6, 6.2.7, 6.2.8, 6.2.9, 6.2.10, 6.2.11, 6.2.12, 6.2.13, 6.3.0, 6.3.1, 6.3.2, 6.3.3, 6.3.4, 6.3.5, 6.3.6, 6.3.7, 6.3.8, 6.3.9, 6.3.10, 6.3.11, 6.4.0, 6.4.1, 6.4.2, 6.4.3, 6.4.4, 6.4.5, 6.4.6, 6.4.7, 6.4.8, 6.5.0, 6.5.1, 6.5.1612 (Splunk Cloud only), 6.5.2, 6.5.3, 6.5.4, 6.6.0, 6.6.1

Was this documentation topic helpful?

Enter your email address, and someone from the documentation team will respond to you:

Please provide your comments here. Ask a question or make a suggestion.

You must be logged into splunk.com in order to post comments. Log in now.

Please try to keep this discussion focused on the content covered in this documentation topic. If you have a more general question about Splunk functionality or are experiencing a difficulty with Splunk, consider posting a question to Splunkbase Answers.

0 out of 1000 Characters