[[search-multi-search]] === Multi Search API Executes several searches with a single API request. [[search-multi-search-api-request]] ==== {api-request-title} `GET //_msearch` [[search-multi-search-api-desc]] ==== {api-description-title} The multi search AP executes several searches from a single API request. The format of the request is similar to the bulk API format and makes use of the newline delimited JSON (NDJSON) format. The structure is as follows (the structure is specifically optimized to reduce parsing if a specific search ends up redirected to another node): [source,js] -------------------------------------------------- header\n body\n header\n body\n -------------------------------------------------- // NOTCONSOLE *NOTE*: the final line of data must end with a newline character `\n`. Each newline character may be preceded by a carriage return `\r`. When sending requests to this endpoint the `Content-Type` header should be set to `application/x-ndjson`. [[search-multi-search-api-path-params]] ==== {api-path-parms-title} include::{docdir}/rest-api/common-parms.asciidoc[tag=index] [[search-multi-search-api-request-body]] ==== {api-request-body-title} `aggregations`:: (Optional, object) Specifies aggregations. include::{docdir}/rest-api/common-parms.asciidoc[tag=from] `max_concurrent_searches`:: (Optional, integer) Specifies the maximum number of concurrent searches the multi search API will execute. This default is based on the number of data nodes and the default search thread pool size. `max_concurrent_shard_requests`:: (Optional, integer) Specifies the maximum number of concurrent shard requests that each sub search request will execute per node. This parameter should be used to protect a single request from overloading a cluster (for example a default request will hit all indices in a cluster which could cause shard request rejections if the number of shards per node is high). Defaults to `5`. In certain scenarios parallelism isn't achieved through concurrent request such that this protection will result in poor performance. For instance in an environment where only a very low number of concurrent search requests are expected it might help to increase this value to a higher number. include::{docdir}/rest-api/common-parms.asciidoc[tag=preference] `query`:: (Optional, <>) Defines the search definition using the <>. include::{docdir}/rest-api/common-parms.asciidoc[tag=routing] include::{docdir}/rest-api/common-parms.asciidoc[tag=search_type] `size`:: (Optional, integer) The number of hits to return. Defaults to `10`. [[search-multi-search-api-response-body]] ==== {api-response-body-title} `responses`:: (array) Includes the search response and status code for each search request matching its order in the original multi search request. If there was a complete failure for a specific search request, an object with `error` message and corresponding status code will be returned in place of the actual search response. [[search-multi-search-api-example]] ==== {api-examples-title} The header part includes which index / indices to search on, the `search_type`, `preference`, and `routing`. The body includes the typical search body request (including the `query`, `aggregations`, `from`, `size`, and so on). [source,js] -------------------------------------------------- $ cat requests {"index" : "test"} {"query" : {"match_all" : {}}, "from" : 0, "size" : 10} {"index" : "test", "search_type" : "dfs_query_then_fetch"} {"query" : {"match_all" : {}}} {} {"query" : {"match_all" : {}}} {"query" : {"match_all" : {}}} {"search_type" : "dfs_query_then_fetch"} {"query" : {"match_all" : {}}} -------------------------------------------------- // NOTCONSOLE [source,js] -------------------------------------------------- $ curl -H "Content-Type: application/x-ndjson" -XGET localhost:9200/_msearch --data-binary "@requests"; echo -------------------------------------------------- // NOTCONSOLE Note, the above includes an example of an empty header (can also be just without any content) which is supported as well. The endpoint allows to also search against an index/indices in the URI itself, in which case it will be used as the default unless explicitly defined otherwise in the header. For example: [source,js] -------------------------------------------------- GET twitter/_msearch {} {"query" : {"match_all" : {}}, "from" : 0, "size" : 10} {} {"query" : {"match_all" : {}}} {"index" : "twitter2"} {"query" : {"match_all" : {}}} -------------------------------------------------- // CONSOLE // TEST[setup:twitter] The above will execute the search against the `twitter` index for all the requests that don't define an index, and the last one will be executed against the `twitter2` index. The `search_type` can be set in a similar manner to globally apply to all search requests. [[msearch-security]] ==== Security See <> [[template-msearch]] ==== Template support Much like described in <> for the _search resource, _msearch also provides support for templates. Submit them like follows for inline templates: [source,js] ----------------------------------------------- GET _msearch/template {"index" : "twitter"} { "source" : "{ \"query\": { \"match\": { \"message\" : \"{{keywords}}\" } } } }", "params": { "query_type": "match", "keywords": "some message" } } {"index" : "twitter"} { "source" : "{ \"query\": { \"match_{{template}}\": {} } }", "params": { "template": "all" } } ----------------------------------------------- // CONSOLE // TEST[setup:twitter] You can also create search templates: [source,js] ------------------------------------------ POST /_scripts/my_template_1 { "script": { "lang": "mustache", "source": { "query": { "match": { "message": "{{query_string}}" } } } } } ------------------------------------------ // CONSOLE // TEST[setup:twitter] [source,js] ------------------------------------------ POST /_scripts/my_template_2 { "script": { "lang": "mustache", "source": { "query": { "term": { "{{field}}": "{{value}}" } } } } } ------------------------------------------ // CONSOLE // TEST[continued] You can use search templates in a _msearch: [source,js] ----------------------------------------------- GET _msearch/template {"index" : "main"} { "id": "my_template_1", "params": { "query_string": "some message" } } {"index" : "main"} { "id": "my_template_2", "params": { "field": "user", "value": "test" } } ----------------------------------------------- // CONSOLE // TEST[continued] [[multi-search-partial-responses]] ==== Partial responses To ensure fast responses, the multi search API will respond with partial results if one or more shards fail. See <> for more information.