Update API

The update API allows to update a document based on a script provided. The operation gets the document (collocated with the shard) from the index, runs the script (with optional script language and parameters), and indexes back the result (also allows to delete, or ignore the operation). It uses versioning to make sure no updates have happened during the "get" and "reindex".

Note, this operation still means full reindex of the document, it just removes some network roundtrips and reduces chances of version conflicts between the get and the index. The _source field needs to be enabled for this feature to work.

For example, let’s index a simple doc:

PUT test/_doc/1
{
    "counter" : 1,
    "tags" : ["red"]
}

Now, we can execute a script that would increment the counter:

POST test/_update/1
{
    "script" : {
        "source": "ctx._source.counter += params.count",
        "lang": "painless",
        "params" : {
            "count" : 4
        }
    }
}

We can add a tag to the list of tags (if the tag exists, it still gets added, since this is a list):

POST test/_update/1
{
    "script" : {
        "source": "ctx._source.tags.add(params.tag)",
        "lang": "painless",
        "params" : {
            "tag" : "blue"
        }
    }
}

We can remove a tag from the list of tags. Note that the Painless function to remove a tag takes as its parameter the array index of the element you wish to remove, so you need a bit more logic to locate it while avoiding a runtime error. Note that if the tag was present more than once in the list, this will remove only one occurrence of it:

POST test/_update/1
{
    "script" : {
        "source": "if (ctx._source.tags.contains(params.tag)) { ctx._source.tags.remove(ctx._source.tags.indexOf(params.tag)) }",
        "lang": "painless",
        "params" : {
            "tag" : "blue"
        }
    }
}

In addition to _source, the following variables are available through the ctx map: _index, _type, _id, _version, _routing, and _now (the current timestamp).

We can also add a new field to the document:

POST test/_update/1
{
    "script" : "ctx._source.new_field = 'value_of_new_field'"
}

Or remove a field from the document:

POST test/_update/1
{
    "script" : "ctx._source.remove('new_field')"
}

And, we can even change the operation that is executed. This example deletes the doc if the tags field contains green, otherwise it does nothing (noop):

POST test/_update/1
{
    "script" : {
        "source": "if (ctx._source.tags.contains(params.tag)) { ctx.op = 'delete' } else { ctx.op = 'none' }",
        "lang": "painless",
        "params" : {
            "tag" : "green"
        }
    }
}

The update API also supports passing a partial document, which will be merged into the existing document (simple recursive merge, inner merging of objects, replacing core "keys/values" and arrays). To fully replace the existing document, the index API should be used instead. The following partial update adds a new field to the existing document:

POST test/_update/1
{
    "doc" : {
        "name" : "new_name"
    }
}

If both doc and script are specified, then doc is ignored. Best is to put your field pairs of the partial document in the script itself.

If doc is specified its value is merged with the existing _source. By default updates that don’t change anything detect that they don’t change anything and return "result": "noop" like this:

POST test/_update/1
{
    "doc" : {
        "name" : "new_name"
    }
}

If name was new_name before the request was sent then the entire update request is ignored. The result element in the response returns noop if the request was ignored.

{
   "_shards": {
        "total": 0,
        "successful": 0,
        "failed": 0
   },
   "_index": "test",
   "_type": "_doc",
   "_id": "1",
   "_version": 7,
   "result": "noop"
}

You can disable this behavior by setting "detect_noop": false like this:

POST test/_update/1
{
    "doc" : {
        "name" : "new_name"
    },
    "detect_noop": false
}

If the document does not already exist, the contents of the upsert element will be inserted as a new document. If the document does exist, then the script will be executed instead:

POST test/_update/1
{
    "script" : {
        "source": "ctx._source.counter += params.count",
        "lang": "painless",
        "params" : {
            "count" : 4
        }
    },
    "upsert" : {
        "counter" : 1
    }
}

If you would like your script to run regardless of whether the document exists or not — i.e. the script handles initializing the document instead of the upsert element — then set scripted_upsert to true:

POST sessions/_update/dh3sgudg8gsrgl
{
    "scripted_upsert":true,
    "script" : {
        "id": "my_web_session_summariser",
        "params" : {
            "pageViewEvent" : {
                "url":"foo.com/bar",
                "response":404,
                "time":"2014-01-01 12:32"
            }
        }
    },
    "upsert" : {}
}

Instead of sending a partial doc plus an upsert doc, setting doc_as_upsert to true will use the contents of doc as the upsert value:

POST test/_update/1
{
    "doc" : {
        "name" : "new_name"
    },
    "doc_as_upsert" : true
}

The update operation supports the following query-string parameters: