I'd be interested to know what drove the technology choices for Java and Apache Solr.
[1] http://lucene.apache.org/core/
[2] we do this (over 300G of complex data) with a tool called solrbulk and on a single server in less than four hours, https://github.com/miku/solrbulk
For this portion of the stack why would it be preferable to start with Lucene rather than Elasticsearch? (for all of the distributed scaling benefits)
That said, looking over Chronix I can't tell if it was supposed to be a primary data store.