The search API allows to execute a search query and get back search hits that match the query. It can be executed across indices and types. The query can either be provided using a simple query string as a parameter, or using a request body.

Routing

When executing a search, it will be broadcasted to all the index/indices shards (round robin between replicas). Which shards will be searched on can be controlled by providing the routing parameter. For example, when indexing tweets, the routing value can be the user name:

$ curl -XPOST 'http://localhost:9200/twitter/tweet?routing=kimchy' -d '{
    "user" : "kimchy",
    "postDate" : "2009-11-15T14:12:12",
    "message" : "trying out Elastic Search"
}
'

In such a case, if we want to search only on the tweets for a specific user, we can specify it as the routing, resulting in the search hitting only the relevant shard:

$ curl -XGET 'http://localhost:9200/twitter/tweet/_search?routing=kimchy' -d '{
    "query": {
        "filtered" : {
            "query" : {
                "query_string" : {
                    "query" : "some query string here"
                }
            },
            "filter" : {
                "term" : { "user" : "kimchy" }
            }
        }
    }
}
'

The routing parameter can be multi valued represented as a comma separated string. This will result in hitting the relevant shards where the routing values match to.

Stats Groups

A search can be associated with stats groups, which maintains a statistics aggregation per group. It can later be retrieved using the indices stats API specifically. For example, here is a search body request that associate the request with two different groups:

{
    "query" : {
        "match_all" : {}
    },
    "stats" : ["group1", "group2"]
}