This Splunk search will show you use and available CPU and Memory statistics. Depending on your environment you may see multiple Splunk servers:

| rest  /services/server/status/resource-usage/hostwide | eval cpu_count = if(isnull(cpu_count), "N/A", cpu_count) | eval cpu_usage = cpu_system_pct + cpu_user_pct | eval mem_used_pct = round(mem_used / mem * 100 , 2) | eval mem_used = round(mem_used, 0) | eval mem = round(mem, 0) |eval mem=tostring(mem, "commas") | eval mem_used=tostring(mem_used, "commas")| fields splunk_server, cpu_count, cpu_usage, mem, mem_used, mem_used_pct | sort - cpu_usage, -mem_used | rename splunk_server AS Instance, cpu_count AS "CPU Cores", cpu_usage AS "CPU Usage (%)", mem AS "Physical Memory Capacity (MB)", mem_used AS "Physical Memory Usage (MB)", mem_used_pct AS "Physical Memory Usage (%)"

Slightly modified from: http://www.brainfold.net/2016/03/frequently-used-rest-api-calls-in-splunk.html