Apache Solr

Apache Solr is one of the most wide-spread open search technologies around.

Built on top of the very successful and appreciated Lucene engine, Solr can be used to search various types of data in various types of environments and platforms.

With full-text search capabilities, Solr is optimized for high volumes of traffic, making ideal for any kind of project, may it be Web or desktop-based.

Solr also provides bindings to XML/HTTP, Ruby, JSON, and Python, for integration with a variety of other Web technologies.

What is new in this release:

• Usability improvements that include improved bin scripts and new and restructured examples.
• Scripts to support installing and running Solr as a service on Linux.
• Distributed IDF is now supported and can be enabled via the config.
• Solr will no longer ship a war file and instead be a downloadable application.
• SolrJ now has first class support for Collections API.
• Implicit registration of replication,get and admin handlers.
• Config API that supports paramsets for easily configuring solr parameters and configuring fields. This API also supports managing of pre-existing request handlers and editing common solrconfig.xml via overlay.
• API for managing blobs allows uploading request handler jars and registering them via config API.
• BALANCESHARDUNIQUE Collection API that allows for even distribution of custom replica properties.
• There's now an option to not shuffle the nodeSet provided during collection creation.
• Option to configure bandwidth usage by Replication handler to prevent it from using up all the bandwidth.
• Splitting of clusterstate to per-collection enables scalability improvement in SolrCloud. This is also the default format for new Collections that would be created going forward.
• timeAllowed is now used to prematurely terminate requests during query expansion and SolrClient request retry.
• pivot.facet results can now include nested stats.field results constrained by those pivots.
• stats.field can be used to generate stats over the results of arbitrary numeric functions. It also allows for requesting for statistics for pivot facets using tags.
• A new DateRangeField has been added for indexing date ranges, especially multi-valued ones.
• Spatial fields that used to require units=degrees now take distanceUnits=degrees/kilometers miles instead.
• MoreLikeThis query parser allows requesting for documents similar to an existing document and also works in SolrCloud mode.
• Logging improvements.

What is new in version 5.2.1 / 4.10.4 / 3.6.2:

• Usability improvements that include improved bin scripts and new and restructured examples.
• Scripts to support installing and running Solr as a service on Linux.
• Distributed IDF is now supported and can be enabled via the config.
• Solr will no longer ship a war file and instead be a downloadable application.
• SolrJ now has first class support for Collections API.
• Implicit registration of replication,get and admin handlers.
• Config API that supports paramsets for easily configuring solr parameters and configuring fields. This API also supports managing of pre-existing request handlers and editing common solrconfig.xml via overlay.
• API for managing blobs allows uploading request handler jars and registering them via config API.
• BALANCESHARDUNIQUE Collection API that allows for even distribution of custom replica properties.
• There's now an option to not shuffle the nodeSet provided during collection creation.
• Option to configure bandwidth usage by Replication handler to prevent it from using up all the bandwidth.
• Splitting of clusterstate to per-collection enables scalability improvement in SolrCloud. This is also the default format for new Collections that would be created going forward.
• timeAllowed is now used to prematurely terminate requests during query expansion and SolrClient request retry.
• pivot.facet results can now include nested stats.field results constrained by those pivots.
• stats.field can be used to generate stats over the results of arbitrary numeric functions. It also allows for requesting for statistics for pivot facets using tags.
• A new DateRangeField has been added for indexing date ranges, especially multi-valued ones.
• Spatial fields that used to require units=degrees now take distanceUnits=degrees/kilometers miles instead.
• MoreLikeThis query parser allows requesting for documents similar to an existing document and also works in SolrCloud mode.
• Logging improvements.

What is new in version 5.1.0 / 4.10.4 / 3.6.2:

• Usability improvements that include improved bin scripts and new and restructured examples.
• Scripts to support installing and running Solr as a service on Linux.
• Distributed IDF is now supported and can be enabled via the config.
• Solr will no longer ship a war file and instead be a downloadable application.
• SolrJ now has first class support for Collections API.
• Implicit registration of replication,get and admin handlers.
• Config API that supports paramsets for easily configuring solr parameters and configuring fields. This API also supports managing of pre-existing request handlers and editing common solrconfig.xml via overlay.
• API for managing blobs allows uploading request handler jars and registering them via config API.
• BALANCESHARDUNIQUE Collection API that allows for even distribution of custom replica properties.
• There's now an option to not shuffle the nodeSet provided during collection creation.
• Option to configure bandwidth usage by Replication handler to prevent it from using up all the bandwidth.
• Splitting of clusterstate to per-collection enables scalability improvement in SolrCloud. This is also the default format for new Collections that would be created going forward.
• timeAllowed is now used to prematurely terminate requests during query expansion and SolrClient request retry.
• pivot.facet results can now include nested stats.field results constrained by those pivots.
• stats.field can be used to generate stats over the results of arbitrary numeric functions. It also allows for requesting for statistics for pivot facets using tags.
• A new DateRangeField has been added for indexing date ranges, especially multi-valued ones.
• Spatial fields that used to require units=degrees now take distanceUnits=degrees/kilometers miles instead.
• MoreLikeThis query parser allows requesting for documents similar to an existing document and also works in SolrCloud mode.
• Logging improvements.

What is new in version 5.0.0 / 4.10.3 / 3.6.2:

• Bug Fixes:
• If using the new global hdfs block cache option, you can end up reading corrupt files on file name reuse.
• CoreContainer reports incorrect & missleading path for solrconfig.xml when there are loading problems
• StatsComponent when using docValues="true" multiValued="true"
• fq exclusion via "ex" local param in multivalued stats.field
• bin/solr script needs to pass -DnumShards=1 for boostrapping collection1 when starting Solr in cloud mode.
• Binary Response Writer does not return wildcard fields.

What is new in version 4.9.0:

• Numerous optimizations for doc values search-time performance
• Allow a client application to request the minium achieved replication factor for an update request (single or batch) by sending an optional parameter "min_rf".
• Query re-ranking support with the new ReRankingQParserPlugin.
• A new [child ...] DocTransformer for optionally including Block-Join descendent documents inline in the results of a search.
• A new (default) Lucene49NormsFormat to better compress certain cases such as very short fields.

What is new in version 4.8.0:

• The new {!complexphrase} query parser supports wildcards, ORs etc. inside Phrase Queries.
• New Collections API CLUSTERSTATUS action reports the status of collections, shards, and replicas, and also lists collection aliases and cluster properties.
• Added managed synonym and stopword filter factories, which enable synonym and stopword lists to be dynamically managed via REST API.
• JSON updates now support nested child documents, enabling {!child} and {!parent} block join queries.
• Added ExpandComponent to expand results collapsed by the CollapsingQParserPlugin, as well as the parent/child relationship of nested child documents.
• Long-running Collections API tasks can now be executed asynchronously; the new REQUESTSTATUS action provides status.
• Added a hl.qparser parameter to allow you to define a query parser for hl.q highlight queries.
• In Solr single-node mode, cores can now be created using named configsets.

What is new in version 4.7.0:

• A new 'migrate' collection API to split all documents with a route key into another collection.
• Added support for tri-level compositeId routing.
• Admin UI - Added a new "Files" conf directory browser/file viewer.
• Added a QParserPlugin for Lucene's SimpleQueryParser.
• SSL support for SolrCloud.

What is new in version 4.6.0:

• Many improvements and enhancements for shard splitting options
• New AnalyzingInfixLookupFactory to leverage the AnalyzingInfixSuggester
• New CollapsingQParserPlugin for high performance field collapsing on high cardinality fields
• New SolrJ APIs for collection management
• New DocBasedVersionConstraintsProcessorFactory providing support for user configured doc-centric versioning rules
• New default index format: Lucene46Codec
• New EnumField type

What is new in version 4.5.0:

• Custom sharding support, including the ability to shard by field.
• DocValue improvements: single valued fields no longer require a default value, allowiing dynamicFields to contain doc values, as well as sortMissingFirst and sortMissingLast on docValue fields.
• Ability to store solr.xml in ZooKeeper.
• Multithreaded faceting.
• CloudSolrServer can now route updates directly to the appropriate shard leader.

What is new in version 4.4.0:

• Schema REST API: Add support for creating copy fields.
• A merged segment warmer may now be plugged into solrconfig.xml.
• New MaxScoreQParserPlugin: Return max() instead of sum() of terms.
• Binary files are now supported in ZooKeeper.
• SolrJ's SolrPing object has new methods for ping, enable, and disable.
• The Admin UI now supports adding documents to Solr.
• Added a PUT command to the Solr ZkCli tool.
• New "deleteshard" collections API that unloads all replicas of a given shard and then removes it from the cluster state. It will remove only those shards which are INACTIVE or have no range.
• The Overseer can now optionally assign generic node names so that new addresses can host shards without naming confusion.
• The CSV Update Handler now supports optionally adding the line number/ row ID to a document.

What is new in version 4.3.0:

• Tired of maintaining core information in solr.xml? Now you can configure Solr to automatically find cores by walking an arbitrary directory.
• Shard Splitting: You can now split SolrCloud shards to expand your cluster as you grow.
• The read side schema REST API has been improved and expanded upon: all schema information is now available and the full live schema can now be returned in JSON or XML. Ground work is included for the upcoming write side of the schema REST API.
• Spatial queries can now search for indexed shapes by "IsWithin",
• "Contains" and "IsDisjointTo" relationships, in addition to typical "Intersects".

What is new in version 4.2:

• Allow custom shard names so that new host addresses can take over for retired shards. Working on Amazon without elastic IPs.
• Lucene 4.2 optimizations such as compressed term vectors.

What is new in version 3.6.2:

• Fixed ConcurrentModificationException during highlighting, if all fields were requested.
• Fixed edismax queryparser to apply minShouldMatch to implicit boolean queries.
• Several bugfixes to the DataImportHandler.

What is new in version 4.0-alpha:

• Solr 4.0-alpha includes more NoSQL features for those using Solr as a
• primary data store.

What is new in version 3.6.0:

• New SolrJ client connector using Apache HTTP Components HTTP client.
• Many analyzer factories are now "multi term query aware" allowing for things like field type aware lowercasing when building prefix & wildcard queries.
• New Kuromoji morphological analyzer tokenizes Japanese text, producing both compound words and their segmentation.
• Range Faceting (Dates & Numbers) is now supported in distributed search.
• HTMLStripCharFilter has been completely re-implemented, fixing many bugs and greatly improving the performance.
• StreamingUpdateSolrServer now supports the javabin format.
• New LFU Cache option for use in Solr's internal caches.
• Memory performance improvements to all FST based suggesters.
• New WFSTLookupFactory suggester supports finer-grained ranking for suggestions.
• New options for configuring the amount of concurrency used in distributed searches.
• Many bug fixes.

What is new in version 3.5.0:

• Bug fixes and improvements from Apache Lucene 3.5.0, including a very substantial (3-5X) RAM reduction required to hold the terms index on opening an IndexReader.
• Added support for distributed result grouping.
• Added support for Hunspell stemmer TokenFilter supporting stemming for 99 languages.
• A new contrib module "langid" adds language identification capabilities as an Update Processor, using Tika's LanguageIdentifier or Cybozu language-detection library.
• Numeric types including Trie and date types now support sortMissingFirst/Last.
• Added hl.q parameter. It is optional and if it is specified, it overrides q parameter in Highlighter.
• Several minor bugfixes like date parsing for years from 0001-1000, ignored configurations when using QueryAnalyzer with SpellCheckComponent and many more.

What is new in version 3.4.0:

• Bug fixes and improvements from Apache Lucene 3.4.0, including a major bug (LUCENE-3418) whereby a Lucene index could easily become corrupted if the OS or computer crashed or lost power.
• SolrJ client can now parse grouped and range facets results.
• A new XsltUpdateRequestHandler allows posting XML that's transformed by a provided XSLT into a valid Solr document.
• Post-group faceting option (group.truncate) can now compute facet counts for only the highest ranking documents per-group.
• Add commitWithin update request parameter to all update handlers that were previously missing it. This tells Solr to commit the change within the specified amount of time.
• Can now specify NIOFSDirectory.
• New parameter hl.phraseLimit speeds up FastVectorHighlighter.
• The query cache and filter cache can now be disabled per request.
• Improved memory usage, build time, and performance of SynonymFilterFactory.
• Added omitPositions to the schema, so you can omit position information while still indexing term frequencies.
• Various fixes for multi-threaded DataImportHandler.

What is new in version 3.3.0:

• Grouping / Field Collapsing
• A new, automaton-based suggest/autocomplete implementation offering an order of magnitude smaller RAM consumption.
• KStemFilterFactory, an optimized implementation of a less aggressive stemmer for English.
• Solr defaults to a new, more efficient merge policy (TieredMergePolicy). See http://s.apache.org/merging for more information.
• Important bugfixes, including extremely high RAM usage in spellchecking.
• Bugfixes and improvements from Apache Lucene 3.3

What is new in version 3.2.0:

• Ability to specify overwrite and commitWithin as request parameters when using the JSON update format.
• TermQParserPlugin, useful when generating filter queries from terms returned from field faceting or the terms component.
• DebugComponent now supports using a NamedList to model Explanation objects in its responses instead of Explanation.toString.
• Improvements to the UIMA and Carrot2 integrations.
• Highlighting performance improvements.
• A test-framework jar for easy testing of Solr extensions.
• Bugfixes and improvements from Apache Lucene 3.2.

What is new in version 3.1.0:

• Numeric range facets (similar to date faceting).
• New spatial search, including spatial filtering, boosting and sorting capabilities.
• Example Velocity driven search UI at http://localhost:8983/solr/browse
• A new termvector-based highlighter
• Extend dismax (edismax) query parser which addresses some missing features in the dismax query parser along with some extensions.
• Several more components now support distributed mode: TermsComponent, SpellCheckComponent.
• A new Auto Suggest component.
• Ability to sort by functions.
• JSON document indexing
• CSV response format
• Apache UIMA integration for metadata extraction
• Leverages Lucene 3.1 and it's inherent optimizations and bug fixes as well as new analysis capabilities.
• Numerous improvements, bug fixes, and optimizations.

What is new in version 1.4.1:

• This is a bug fix release - no changes are required when upgrading from Solr 1.4.