Solr 4x continues its march forward with the release of Solr 4.4 this week!

Schemaless in d’house!

Probably the biggest news is the new schemaless mode, or perhaps more aptly named schema guessing,
where Solr tries to figure out what data-types to use based on the data you submit.
While this puts to rest one of the bigger remaining complaints about Solr, it’s not recommended for production;
this is the same recommendation that other schemaless engines advise.
For example, if you’re going to be sorting and faceting over millions and millions of documents,
you want to use the most compact numeric type that will suffice for your numeric fields.
An interesting side effect of this is that the parsing methods added to support schemaless
can also be used by more traditional data indexing processes.

Some other “Big Ticket” items likely to excite the community:

  • The Admin UI now supports adding documents to Solr.
    Combined with schemaless, this should help new Solr
    users and developers
    get things up and running on day 1.
  • Solr can now store its index files in HDFS
    (Hadoop File System).
    This is a continuation of Solr’s expansion in Big Data and NoSQL territory.

For casual developers there are some nice new features:

  • You can now add copyField directives via the schema API
  • Indexed CSV data can now include line numbers
  • Score calculation tweak in MaxScoreQParserPlugin
  • Cores don’t need to be manually listed in solr.xml anymore, Solr finds them automatically
  • You can get system-wide information with a single REST API call
  • New findRecursive method in NamedList (NamedList is the main SolrJ data structure)
  • Performance tweak to spellcheck collator if you don’t need exact doc counts

For admins who work a lot with shards and ZooKeeper, Solr 4.4 adds some capabilities:

  • ZK tool now supports PUT
  • ZK now supports Binary files
  • The Overseer can use generic names, which helps with shards on new machines
  • New deleteshard API (it’s careful to remove only those shards which are INACTIVE or have no range)

There are of course many other fixes and tweaks, see the links below.

Solr 4.4 Links