[[breaking-changes-3.0]] == Breaking changes in 3.0 This section discusses the changes that you need to be aware of when migrating your application to Elasticsearch 3.0. === Search changes ==== `search_type=count` removed The `count` search type was deprecated since version 2.0.0 and is now removed. In order to get the same benefits, you just need to set the value of the `size` parameter to `0`. For instance, the following request: [source,sh] --------------- GET /my_index/_search?search_type=count { "aggs": { "my_terms": { "terms": { "field": "foo" } } } } --------------- can be replaced with: [source,sh] --------------- GET /my_index/_search { "size": 0, "aggs": { "my_terms": { "terms": { "field": "foo" } } } } --------------- ==== `search_type=scan` removed The `scan` search type was deprecated since version 2.1.0 and is now removed. All benefits from this search type can now be achieved by doing a scroll request that sorts documents in `_doc` order, for instance: [source,sh] --------------- GET /my_index/_search?scroll=2m { "sort": [ "_doc" ] } --------------- Scroll requests sorted by `_doc` have been optimized to more efficiently resume from where the previous request stopped, so this will have the same performance characteristics as the former `scan` search type. === Parent/Child changes The `children` aggregation, parent child inner hits and `has_child` and `has_parent` queries will not work on indices with `_parent` field mapping created before version `2.0.0`. The data of these indices need to be re-indexed into a new index. The format of the join between parent and child documents have changed with the `2.0.0` release. The old format can't read from version `3.0.0` and onwards. The new format allows for a much more efficient and scalable join between parent and child documents and the join data structures are stored on on disk data structures as opposed as before the join data structures were stored in the jvm heap space. ==== `score_type` has been removed The `score_type` option has been removed from the `has_child` and `has_parent` queries in favour of the `score_mode` option which does the exact same thing. ==== `sum` score mode removed The `sum` score mode has been removed in favour of the `total` mode which doesn the same and is already available in previous versions. ==== `max_children` option When `max_children` was set to `0` on the `has_child` query then there was no upper limit on how many children documents are allowed to match. This has changed and `0` now really means to zero child documents are allowed. If no upper limit is needed then the `max_children` option shouldn't be defined at all on the `has_child` query. === Settings changes === ==== Ping timeout settings Previously, there were three settings for the ping timeout: `discovery.zen.initial_ping_timeout`, `discovery.zen.ping.timeout` and `discovery.zen.ping_timeout`. The former two have been removed and the only setting key for the ping timeout is now `discovery.zen.ping_timeout`. The default value for ping timeouts remains at three seconds. === Plugins Plugins implementing custom queries need to implement the `fromXContent(QueryParseContext)` method in their `QueryParser` subclass rather than `parse`. This method will take care of parsing the query from `XContent` format into an intermediate query representation that can be streamed between the nodes in binary format, effectively the query object used in the java api. Also, the query parser needs to implement the `getBuilderPrototype` method that returns a prototype of the `NamedWriteable` query, which allows to deserialize an incoming query by calling `readFrom(StreamInput)` against it, which will create a new object, see usages of `Writeable`. The `QueryParser` also needs to declare the generic type of the query that it supports and it's able to parse. The query object can then transform itself into a lucene query through the new `toQuery(QueryShardContext)` method, which returns a lucene query to be executed on the data node. Similarly, plugins implementing custom score functions need to implement the `fromXContent(QueryParseContext)` method in their `ScoreFunctionParser` subclass rather than `parse`. This method will take care of parsing the function from `XContent` format into an intermediate function representation that can be streamed between the nodes in binary format, effectively the function object used in the java api. Also, the query parser needs to implement the `getBuilderPrototype` method that returns a prototype of the `NamedWriteable` function, which allows to deserialize an incoming function by calling `readFrom(StreamInput)` against it, which will create a new object, see usages of `Writeable`. The `ScoreFunctionParser` also needs to declare the generic type of the function that it supports and it's able to parse. The function object can then transform itself into a lucene function through the new `toFunction(QueryShardContext)` method, which returns a lucene function to be executed on the data node. === Java-API ==== BoostingQueryBuilder Removed setters for mandatory positive/negative query. Both arguments now have to be supplied at construction time already and have to be non-null. ==== SpanContainingQueryBuilder Removed setters for mandatory big/little inner span queries. Both arguments now have to be supplied at construction time already and have to be non-null. Updated static factory methods in QueryBuilders accordingly. ==== SpanOrQueryBuilder Making sure that query contains at least one clause by making initial clause mandatory in constructor. ==== SpanNearQueryBuilder Removed setter for mandatory slop parameter, needs to be set in constructor now. Also making sure that query contains at least one clause by making initial clause mandatory in constructor. Updated the static factory methods in QueryBuilders accordingly. ==== SpanNotQueryBuilder Removed setter for mandatory include/exclude span query clause, needs to be set in constructor now. Updated the static factory methods in QueryBuilders and tests accordingly. ==== SpanWithinQueryBuilder Removed setters for mandatory big/little inner span queries. Both arguments now have to be supplied at construction time already and have to be non-null. Updated static factory methods in QueryBuilders accordingly. ==== QueryFilterBuilder Removed the setter `queryName(String queryName)` since this field is not supported in this type of query. Use `FQueryFilterBuilder.queryName(String queryName)` instead when in need to wrap a named query as a filter. ==== WrapperQueryBuilder Removed `wrapperQueryBuilder(byte[] source, int offset, int length)`. Instead simply use `wrapperQueryBuilder(byte[] source)`. Updated the static factory methods in QueryBuilders accordingly. ==== QueryStringQueryBuilder Removed ability to pass in boost value using `field(String field)` method in form e.g. `field^2`. Use the `field(String, float)` method instead. ==== Operator Removed the enums called `Operator` from `MatchQueryBuilder`, `QueryStringQueryBuilder`, `SimpleQueryStringBuilder`, and `CommonTermsQueryBuilder` in favour of using the enum defined in `org.elasticsearch.index.query.Operator` in an effort to consolidate the codebase and avoid duplication. ==== queryName and boost support Support for `queryName` and `boost` has been streamlined to all of the queries. That is a breaking change till queries get sent over the network as serialized json rather than in `Streamable` format. In fact whenever additional fields are added to the json representation of the query, older nodes might throw error when they find unknown fields. ==== InnerHitsBuilder InnerHitsBuilder now has a dedicated addParentChildInnerHits and addNestedInnerHits methods to differentiate between inner hits for nested vs. parent / child documents. This change makes the type / path parameter mandatory. ==== MatchQueryBuilder Moving MatchQueryBuilder.Type and MatchQueryBuilder.ZeroTermsQuery enum to MatchQuery.Type. Also reusing new Operator enum. ==== MoreLikeThisQueryBuilder Removed `MoreLikeThisQueryBuilder.Item#id(String id)`, `Item#doc(BytesReference doc)`, `Item#doc(XContentBuilder doc)`. Use provided constructors instead. Removed `MoreLikeThisQueryBuilder#addLike` in favor of texts and/or items beeing provided at construction time. Using arrays there instead of lists now. Removed `MoreLikeThisQueryBuilder#addUnlike` in favor to using the `unlike` methods which take arrays as arguments now rather than the lists used before. The deprecated `docs(Item... docs)`, `ignoreLike(Item... docs)`, `ignoreLike(String... likeText)`, `addItem(Item... likeItems)` have been removed. ==== GeoDistanceQueryBuilder Removing individual setters for lon() and lat() values, both values should be set together using point(lon, lat). ==== GeoDistanceRangeQueryBuilder Removing setters for to(Object ...) and from(Object ...) in favour of the only two allowed input arguments (String, Number). Removing setter for center point (point(), geohash()) because parameter is mandatory and should already be set in constructor. Also removing setters for lt(), lte(), gt(), gte() since they can all be replaced by equivallent calls to to/from() and inludeLower()/includeUpper(). ==== GeoPolygonQueryBuilder Require shell of polygon already to be specified in constructor instead of adding it pointwise. This enables validation, but makes it necessary to remove the addPoint() methods. ==== MultiMatchQueryBuilder Moving MultiMatchQueryBuilder.ZeroTermsQuery enum to MatchQuery.ZeroTermsQuery. Also reusing new Operator enum. Removed ability to pass in boost value using `field(String field)` method in form e.g. `field^2`. Use the `field(String, float)` method instead. ==== MissingQueryBuilder The two individual setters for existence() and nullValue() were removed in favour of optional constructor settings in order to better capture and validate their interdependent settings at construction time. ==== TermsQueryBuilder Remove the setter for `termsLookup()`, making it only possible to either use a TermsLookup object or individual values at construction time. Also moving individual settings for the TermsLookup (lookupIndex, lookupType, lookupId, lookupPath) to the separate TermsLookup class, using constructor only and moving checks for validation there. Removed `TermsLookupQueryBuilder` in favour of `TermsQueryBuilder`. ==== FunctionScoreQueryBuilder `add` methods have been removed, all filters and functions must be provided as constructor arguments by creating an array of `FunctionScoreQueryBuilder.FilterFunctionBuilder` objects, containing one element for each filter/function pair. `scoreMode` and `boostMode` can only be provided using corresponding enum members instead of string values: see `FilterFunctionScoreQuery.ScoreMode` and `CombineFunction`. `CombineFunction.MULT` has been renamed to `MULTIPLY`. ==== IdsQueryBuilder For simplicity, only one way of adding the ids to the existing list (empty by default) is left: `addIds(String...)` ==== DocumentAlreadyExistsException removed `DocumentAlreadyExistsException` is removed and a `VersionConflictException` is thrown instead (with a better error description). This will influence code that use the `IndexRequest.opType()` or `IndexRequest.create()` to index a document only if it doesn't already exist.