One fundamental difference between ElasticSearch and Solr

This seems to be comparing ElasticSearch to Solr 3.x which is disingenuous. Solr 4.0 has been released for months now and includes many new features around distributed search and indexing.<p>Just to point out a few corrections: * Solr does have a transaction log. When using soft commits, the tx log is used to recover any volatile writes in the event of a crash * Solr replicates in a similar manner to ES. It no longer does full-index replication as indicated by the article. A write comes in and is routed to the shard leader and replicas. * Solr too has "High Availability built-in" with automatic failover of shards<p>One fundamental difference the article does not address is the robustness of Solr's cluster management. Solr uses ZooKeeper under the hood which implements the Paxos algorithm to avoid issues like "split-brain syndrome". ElasticSearch has implemented its own distributed coordination and is susceptible to such issues.

Alex provides summary about the main difference of ES vs. Solr, ie., the distributed, dynamic indexes vs. fast static index search speeds. Here is an somewhat older article highlighting this difference in numbers (search time) and explaining why percolation matters (and what it is) for ES (and not so much for Solr), although from about two years ago:<p><a href="http://blog.socialcast.com/realtime-search-solr-vs-elasticsearch/" rel="nofollow">http://blog.socialcast.com/realtime-search-solr-vs-elasticse...</a><p>It should probably be pointed out that this comparison is slightly unfair as of Solr 4, however, and needs to be re-compared against a SolrCloud... But given SC relies on ZooKeeper, this is not nearly as easy a setup as EC.