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 index 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, lets index a simple doc:

curl -XPUT localhost:9200/test/type1/1 -d '{
    "counter" : 1,
    "tags" : ["red"]
}'

Scripted updates

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

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : {
        "inline": "ctx._source.counter += count",
        "params" : {
            "count" : 4
        }
    }
}'

We can add a tag to the list of tags (note, if the tag exists, it will still add it, since its a list):

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : {
        "inline": "ctx._source.tags += tag",
        "params" : {
            "tag" : "blue"
        }
    }
}'

In addition to _source, the following variables are available through the ctx map: _index, _type, _id, _version, _routing, _parent, _timestamp, _ttl.

We can also add a new field to the document:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : "ctx._source.name_of_new_field = \"value_of_new_field\""
}'

Or remove a field from the document:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : "ctx._source.remove(\"name_of_field\")"
}'

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

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : {
        "inline": "ctx._source.tags.contains(tag) ? ctx.op = \"delete\" : ctx.op = \"none\"",
        "params" : {
            "tag" : "blue"
        }
    }
}'

Updates with a partial document

The update API also support 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). For example:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "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.

Detecting noop updates

If doc is specified its value is merged with the existing _source. By default the document is only reindexed if the new _source field differs from the old. Setting detect_noop to false will cause Elasticsearch to always update the document even if it hasn’t changed. For example:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "doc" : {
        "name" : "new_name"
    },
    "detect_noop": false
}'

If name was new_name before the request was sent then document is still reindexed.

Upserts

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:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "script" : {
        "inline": "ctx._source.counter += count",
        "params" : {
            "count" : 4
        }
    },
    "upsert" : {
        "counter" : 1
    }
}'

scripted_upsert

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:

curl -XPOST 'localhost:9200/sessions/session/dh3sgudg8gsrgl/_update' -d '{
    "scripted_upsert":true,
    "script" : {
        "id": "my_web_session_summariser",
        "params" : {
            "pageViewEvent" : {
                "url":"foo.com/bar",
                "response":404,
                "time":"2014-01-01 12:32"
            }
        }
    },
    "upsert" : {}
}'

doc_as_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:

curl -XPOST 'localhost:9200/test/type1/1/_update' -d '{
    "doc" : {
        "name" : "new_name"
    },
    "doc_as_upsert" : true
}'

Parameters

The update operation supports the following query-string parameters:

retry_on_conflict

In between the get and indexing phases of the update, it is possible that another process might have already updated the same document. By default, the update will fail with a version conflict exception. The retry_on_conflict parameter controls how many times to retry the update before finally throwing an exception.

routing

Routing is used to route the update request to the right shard and sets the routing for the upsert request if the document being updated doesn’t exist. Can’t be used to update the routing of an existing document.

parent

Parent is used to route the update request to the right shard and sets the parent for the upsert request if the document being updated doesn’t exist. Can’t be used to update the parent of an existing document.

timeout

Timeout waiting for a shard to become available.

consistency

The write consistency of the index/delete operation.

refresh

Refresh the relevant primary and replica shards (not the whole index) immediately after the operation occurs, so that the updated document appears in search results immediately.

fields

Return the relevant fields from the updated document. Specify _source to return the full updated source.

version & version_type

The update API uses the Elasticsearch’s versioning support internally to make sure the document doesn’t change during the update. You can use the version parameter to specify that the document should only be updated if its version matches the one specified. By setting version type to force you can force the new version of the document after update (use with care! with force there is no guarantee the document didn’t change).

The update API does not support external versioning

External versioning (version types external & external_gte) is not supported by the update API as it would result in Elasticsearch version numbers being out of sync with the external system. Use the index API instead.