Hi sarit_s
You do not need to integrate any external tool to evaluate the performance of your Splunk. As splunk itself is a log monitoring tool and can very well deduce the external as well its internal logs to give you the performance metrics that you want.
At a high level, you can refer to the following Dashboards on Monitoring Console -
Overview (Check the CPU and Memory of all of your Splunk components of your distributed env)
Instances (Check the OS, CPU usage/process, RAM usage/process, Disk usage, Historical charts of these resource usage, Availability)
Search Activity (Adhoc + Scheduled searches, Resource usage specifically by search activities, search concurrency, Top memory consuming searches, Searches started per minute, Aggregate search Runtimes etc)
Resource usage (CPU cores, Avg load, % usage of memory, CPU and Disk Per Instance, machine or deployment, historical charts, I/O bandwidth utilization)
etc.
There are more dashboards that you might fit for your relevance.
Please accept this as answer if this resolves your query.
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