The best replacement for splunk is hadoop.

The best alternatives to splunk are rated as following:
★★★★★  hadoop
★★★★  arcsight
★★★★  logstash
★★★  tableau
★★  nagios
★★  elasticsearch
★★  siem
★★  scom
★★  solarwinds
★★  sumo logic
★★  logrhythm
★★  loglogic
★★  loggly
★  qradar
★  palantir
★  new relic
★  envision
  kiwi
  logger
  zenoss
  alienvault
  netwitness
  appdynamics

Your alternative for splunk is not listed? Suggest!
Speaking about splunk, one probably shouldn't forget about nagios.

Other search terms related to splunk and their ratings are:
★★★★★ nagios
★★★★ syslog-ng
★★★★ syslog
★★★ ossec
★★★ snort
★★ snmp
★★ f5
★ netflow
You have in mind a companion for splunk and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of splunk in all years. Click on graph for more.
splunk
hadoop
arcsight