Random order & pagination Elasticsearch

This should be considerably faster than both answers above and supports seeding:

curl -XGET 'localhost:9200/_search' -d '{  "query": {    "function_score" : {      "query" : { "match_all": {} },      "random_score" : {}    }  }}';

See: https://github.com/elasticsearch/elasticsearch/issues/1170

You can sort using a hash function of a unique field (for example id) and a random salt. Depending on how truly random the results should be, you can do something as primitive as:

{  "query" : { "query_string" : {"query" : "*:*"} },  "sort" : {    "_script" : {         "script" : "(doc['_id'].value + salt).hashCode()",        "type" : "number",        "params" : {            "salt" : "some_random_string"        },        "order" : "asc"    }  }}

or something as sophisticated as

{  "query" : { "query_string" : {"query" : "*:*"} },  "sort" : {    "_script" : {         "script" : "org.elasticsearch.common.Digest.md5Hex(doc['_id'].value + salt)",        "type" : "string",        "params" : {            "salt" : "some_random_string"        },        "order" : "asc"    }  }}

The second example will produce more random results but will be somewhat slower.

For this approach to work the field _id has to be stored. Otherwise, the query will fail with NullPointerException.

Good solution from imotov.

Here is something much more simple and you don't need to rely in a document property:

{  "query" : { "query_string" : {"query" : "*:*"} },  "sort" : {    "_script" : {         "script" : "Math.random()",        "type" : "number",        "params" : {},        "order" : "asc"    }  }}

if you want to set a range that would be something like:

{  "query" : { "query_string" : {"query" : "*:*"} },  "sort" : {    "_script" : {         "script" : "Math.random() * (myMax - myMin) + myMin",        "type" : "number",        "params" : {},        "order" : "asc"    }  }}

replacing the max and min with your proper values.