Pretty thorough comparison of the feature sets in Solr and ElasticSearch put together by Kelvin Tan with 4 main sections: API, indexing, searching, customizability, distributed, but many many features considered for each of them.
Apache Solr vs ElasticSearch
✚ The complete website source is on GitHub so if one would like to improve it, it’s easy.
✚ Feature checklists should not be used to making final technical decisions. But they are extremely useful in the early stages of the decision process when having to go through a lot of options.
✚ I know this will Solr vs ElasticSearch comparison will evolve over time, so I’ve starred the project on Github and also saved the current version as PDF.
Original title and link: Apache Solr Versus ElasticSearch - the Feature Smackdown ( ©myNoSQL)