The best replacement for elasticsearch is solr.

The best alternatives to elasticsearch are rated as following:
★★★★★  solr
★★★★  mongodb
★★★  sphinx
★★★  splunk
★★  cloudsearch
★★  hadoop
★★  redis
★  query
★  solrcloud
★  filter
★  couchbase
★  riak
★  google search appliance
★  hbase
  lucene
  lucidworks

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

Other search terms related to elasticsearch and their ratings are:
★★★★★ mongodb
★★★★ kibana
★★★★ logstash
★★★★ couchbase
★★★ cassandra
★ couchdb
You have in mind a companion for elasticsearch and it is not yet here? Propose!



Google Trends

Scale is based on the average worldwide traffic of elasticsearch in all years. Click on graph for more.
elasticsearch
solr
mongodb