See CHANGES.txt, but 4.2 is pretty much bug fixing, I don't think there's anything special you need to do.
Best Erick On Tue, Mar 12, 2013 at 1:31 PM, Marthi, Suneel <smar...@verisign.com>wrote: > We presently have Indexes generated from Solr 4.1. What is the upgrade > path to Solr 4.2 ? > > > > On 3/11/13 8:37 PM, "Robert Muir" <rm...@apache.org> wrote: > > >March 2013, Apache Solr 4.2 available > >The Lucene PMC is pleased to announce the release of Apache Solr 4.2 > > > >Solr is the popular, blazing fast, open source NoSQL search platform > >from the Apache Lucene project. Its major features include powerful > >full-text search, hit highlighting, faceted search, dynamic > >clustering, database integration, rich document (e.g., Word, PDF) > >handling, and geospatial search. Solr is highly scalable, providing > >fault tolerant distributed search and indexing, and powers the search > >and navigation features of many of the world's largest internet sites. > > > >Solr 4.2 is available for immediate download at: > > http://lucene.apache.org/solr/mirrors-solr-latest-redir.html > > > >See the CHANGES.txt file included with the release for a full list of > >details. > > > >Solr 4.2 Release Highlights: > > > >* A read side REST API for the schema. Always wanted to introspect the > >schema over http? Now you can. Looks like the write side will be > >coming next. > > > >* DocValues have been integrated into Solr. DocValues can be loaded up > >a lot faster than the field cache and can also use different > >compression algorithms as well as in RAM or on Disk representations. > >Faceting, sorting, and function queries all get to benefit. How about > >the OS handling faceting and sorting caches off heap? No more tuning > >60 gigabyte heaps? How about a snappy new per segment DocValues > >faceting method? Improved numeric faceting? Sweet. > > > >* Collection Aliasing. Got time based data? Want to re-index in a > >temporary collection and then swap it into production? Done. Stay > >tuned for Shard Aliasing. > > > >* Collection API responses. The collections API was still very new in > >4.0, and while it improved a fair bit in 4.1, responses were certainly > >needed, but missed the cut off. Initially, we made the decision to > >make the Collection API super fault tolerant, which made responses > >tougher to do. No one wants to hunt through logs files to see how > >things turned out. Done in 4.2. > > > >* Interact with any collection on any node. Until 4.2, you could only > >interact with a node in your cluster if it hosted at least one replica > >of the collection you wanted to query/update. No longer - query any > >node, whether it has a piece of your intended collection or not and > >get a proxied response. > > > >* Allow custom shard names so that new host addresses can take over > >for retired shards. Working on Amazon without elastic ips? This is for > >you. > > > >* Lucene 4.2 optimizations such as compressed term vectors. > > > >Solr 4.2 also includes many other new features as well as numerous > >optimizations and bugfixes. > > > >Please report any feedback to the mailing lists > >(http://lucene.apache.org/solr/discussion.html) > > > >Note: The Apache Software Foundation uses an extensive mirroring > >network for distributing releases. It is possible that the mirror you > >are using may not have replicated the release yet. If that is the > >case, please try another mirror. This also goes for Maven access. > > > >Happy searching, > >Lucene/Solr developers > >
