Incompatible changes:

• Gateway: Internal refactoring, requires manual upgrade when using fs gateway. (#232)
• This release allows a newly started node to reuse up-to-date files in the working directory, without having to pull them from the gateway/master every time. Makes restarting a node much faster. This feature requires complete data re-indexing. (Note that when re-indexing data the metadata is automatically re-created too.)
• The service wrapper has been moved to its own repo: http://github.com/elasticsearch/elasticsearch-servicewrapper. (#243)
• Jgroups has been removed – now uses Zen instead
• The terms API has been replaced by facets in search. (#242)
• The search.facets API has changed (see below)
• The shard level index.store.memory settings have been replaced with a node level memory store. (#235)
• REST API: Cluster state (where possible) now returns the mappings as JSON, rather than as a string containing JSON.
• REST Search API: Change score to _score to denote sorting by hit score. (#271)
• Removed cloud plugin
• Mapping: Revise dynamic mapping (into default), merge default to new mappings. (#275)

Enhancements:

Query DSL

• Term Facets: A lot of work has been done to improve facet support:
  • Specify term facets that return the N most frequent terms that a field has, either globally, or bound by the search query (#207). See docs.
  • Facets can be filtered, by the same filters used in queries (#217). See docs.
  • A list of terms can be excluded from the results (#246). See docs.
  • Statistical facets: min, max, total, count, sum_of_squares, variance and std_deviation for numeric fields (#212). See docs.
  • Scripted statistical facets: define a script to be evaluated with statistical facets (#227). See docs.
  • Histogram facets: Create buckets from the values of one field (eg timestamp) and query total and count for another field in the same doc (#219). See docs.
• Terms Factes: Allow to provide regex controlling which terms should be included. (#277)
• Custom scripts:
  • Custom score (scripted) query. (#220)
    • The custom_score query uses the mvel scripting language to provide custom scoring for searches. For instance, you could use this to make documents with a more recent last_modified date more relevant than older documents. These mini-scripts can also accept parameters.
  • Script fields – searches can use the mvel scripting language to return calculated fields. (#221)
• Fuzzy query support. (#213)
• Alternate syntax for prefix (docs), term (docs), wildcard (docs), and span_term (docs) queries. (#192)
• and, or and not filters (#216). See docs.
• Cluster state (see docs):
  • Added parameters to filter the state on nodes, routing_table, metadata, and indices. (#234)
  • Now also includes information about index aliases, blocks and master_node id.
• Added /_mapping, /{index}/_mapping and /{index}/{type}/_mapping to REST interface (#222). See docs.
• Return the maxScore per search and _score for each search hit. (#205)

Other

• Memory management much improved
• Make replication type for index, delete, and delete_by_query operations configurable: async or sync (#196).
• Java API has been improved (#199)
• FS Gateway: Added index.gateway.fs.native_copy to control where native file copying will be used. (#202)
• Plugins: Easier to plugin a custom DSL query/filter parsers. (#208)
• Flush API: Added the full parameter for a complete clean. (#210)
• Gateway: Configurable recovery_after_time and recover_after_nodes. (#223)
• Automatic (and configurable) management of indexing buffer size. (#241)
• Better behaviour when the whole cluster is shut down. (#250)
• Time values (eg durations) now support days as well, eg “2d”
• Zen Discovery: Configure which nodes are or are not allowed to become master with discovery.zen.master. (#248)
• Analysis:
  • Fields that are not_analyzed should automatically default to keyword analyzer. (#229)
  • When specifying empty array for stopwords, use an empty list for stopwords. (#230)
• Make merging mappings smarter. (#253)
• Translog: Implement a file system based translog and make it the default. (#260)
• If there isn’t a valid score for result hits then return null for max_score value. (#263). The same logic applies also to _score values of individual documents.
• Support Cross-Origin resource in http/rest module. (#218)
• Cluster Health API: Add wait_for_nodes (accepts “N”, “<N”, “>N”, “<=N”, and “>=N”). (#269)
• Implemented specific cloud plugin for AWS with S3 gateway and EC2 discovery.
• Analysis: Add pattern analyzer. (#276)

Bug fixes:

• Zen Discovery:
  • Ungraceful shutdown of the master and start of replacement node might cause the cluster not to elect a new master. (#200)
  • When a master node is forcefully killed, other nodes might not monitor the other elected master. (#224)
  • A node might get into an infinite state of trying to find a master (when client / non_master) nodes exists. (#247)
• Don’t create / use the work directory if not needed (for example, on client / non data) nodes. (#249)
• Nodes Info API: Failed to generate REST response when node attributes are set. (#201)
• REST API does not expose node-master status. (#203)
• Query DSL: field query does not take into account allow_leading_wildcards. (#236)
• Added checks to ensure survival when a cached stream is removed mid process
• Search requests hangs when no indices exists. (#209)
• Don’t fail when a flush cannot be completed
• Cluster state is now refreshed on restart, clearing out old information.
• Block operations performed on a cluster until it has recovered from the gateway. (#239)
• Put Mapping fails when an analyzer is specified that was not configured. (#252)
• Sorting breaks when sorting on a field that has no value in some documents.
• Facet results vary depending on size. (#259)
• Querying mapping on a non-master throws an error. (#261)
• Put Mapping: When updating existing mappings, the request returns with acknowledged `false`. (#262)
• Search: Sending a request that fails to parse can cause file leaks. (#270)
• Mapping: Dynamic mapping definitions are ignored. (#274)

Internal:

• Library upgrades:
  • Lucene: now at version 3.0.2.
  • netty: now at version 3.2.1 Final
  • async http client: now at 1.0.0
• Use Java’s user.dir as the default path.home location
• cached termsSet used in dfs phase
• Logging improvements
• Update build files to reference hamcrest
• Always start the unicast ping discovery, so unicast discovery will work even when using multicast
• Rest interface now accepts HTTP OPTIONS and HEAD
• Clean up files that are in the working directory but not in the gateway
• Big jarjar refactoring, guice now jarjar’ed
• Tcp Transport: Reduce transport.tcp.connection_per_node from 5 to 1. (#225)
• Detect write errors early and notify transport handler
• Connect to a node when it joins the cluster on the disco level, so if it fails, it will be propagated back and the node will not be added to the cluster state
• Simplify netty transport to use single channel
• Refactor builder requets into common base class
• Groovy:
  • Refactor util.xcontent to common.xcontent in client
  • Add prepare methods to groovy APIs
• Gateway: HDFS gateway refactored to use the new common blobstore
• Improve join process in cluster, fetch the cluster meta-data on join and handle new meta data