How the number of concurrent users impacts Splunk performance
This topic discusses how the number of concurrent users impacts Splunk's performance on a single indexer.
A reference Splunk indexer needs to dedicate one of its available CPU cores for every user that logs into the system. This CPU core only handles the actual session itself. When a user starts searching, each search request takes up an additional CPU core, for as long as the search is active.
These figures assume that CPUs are idle when they receive a login or search request. This does not account for other system requests, or CPU cores used by Splunk to index data. If they're processing any other system requests, then the load splits across other available CPUs.
As CPU cores get used up, all activities on an indexer slow down as the computer splits processing time between indexing, search, and handling on-line users. At that point, only additional indexers can increase capacity for all three functions of Splunk operation.
How indexed data impacts Splunk performance
How saved searches affect Splunk performance
This documentation applies to the following versions of Splunk® Enterprise: 5.0, 5.0.1, 5.0.2, 5.0.3, 5.0.4, 5.0.5, 5.0.6, 5.0.7, 5.0.8, 5.0.9, 5.0.10, 5.0.11, 5.0.12, 5.0.13, 5.0.14, 5.0.15, 5.0.16, 5.0.17, 5.0.18