[[docs-bulk]]
== Bulk API

The bulk API makes it possible to perform many index/delete operations
in a single API call. This can greatly increase the indexing speed.

.Client support for bulk requests
*********************************************

Some of the officially supported clients provide helpers to assist with
bulk requests and reindexing of documents from one index to another:

Perl::

    See https://metacpan.org/pod/Search::Elasticsearch::Bulk[Search::Elasticsearch::Bulk]
    and https://metacpan.org/pod/Search::Elasticsearch::Scroll[Search::Elasticsearch::Scroll]

Python::

    See http://elasticsearch-py.readthedocs.org/en/master/helpers.html[elasticsearch.helpers.*]

*********************************************

The REST API endpoint is `/_bulk`, and it expects the following JSON
structure:

[source,js]
--------------------------------------------------
action_and_meta_data\n
optional_source\n
action_and_meta_data\n
optional_source\n
....
action_and_meta_data\n
optional_source\n
--------------------------------------------------

*NOTE*: the final line of data must end with a newline character `\n`.

The possible actions are `index`, `create`, `delete` and `update`.
`index` and `create` expect a source on the next
line, and have the same semantics as the `op_type` parameter to the
standard index API (i.e. create will fail if a document with the same
index and type exists already, whereas index will add or replace a
document as necessary). `delete` does not expect a source on the
following line, and has the same semantics as the standard delete API.
`update` expects that the partial doc, upsert and script and its options
are specified on the next line.

If you're providing text file input to `curl`, you *must* use the
`--data-binary` flag instead of plain `-d`. The latter doesn't preserve
newlines. Example:

[source,js]
--------------------------------------------------
$ cat requests
{ "index" : { "_index" : "test", "_type" : "type1", "_id" : "1" } }
{ "field1" : "value1" }
$ curl -s -XPOST localhost:9200/_bulk --data-binary @requests; echo
{"took":7,"items":[{"create":{"_index":"test","_type":"type1","_id":"1","_version":1}}]}
--------------------------------------------------

Because this format uses literal `\n`'s as delimiters, please be sure
that the JSON actions and sources are not pretty printed. Here is an
example of a correct sequence of bulk commands:

[source,js]
--------------------------------------------------
{ "index" : { "_index" : "test", "_type" : "type1", "_id" : "1" } }
{ "field1" : "value1" }
{ "delete" : { "_index" : "test", "_type" : "type1", "_id" : "2" } }
{ "create" : { "_index" : "test", "_type" : "type1", "_id" : "3" } }
{ "field1" : "value3" }
{ "update" : {"_id" : "1", "_type" : "type1", "_index" : "index1"} }
{ "doc" : {"field2" : "value2"} }
--------------------------------------------------

In the above example `doc` for the `update` action is a partial
document, that will be merged with the already stored document.

The endpoints are `/_bulk`, `/{index}/_bulk`, and `{index}/{type}/_bulk`.
When the index or the index/type are provided, they will be used by
default on bulk items that don't provide them explicitly.

A note on the format. The idea here is to make processing of this as
fast as possible. As some of the actions will be redirected to other
shards on other nodes, only `action_meta_data` is parsed on the
receiving node side.

Client libraries using this protocol should try and strive to do
something similar on the client side, and reduce buffering as much as
possible.

The response to a bulk action is a large JSON structure with the
individual results of each action that was performed. The failure of a
single action does not affect the remaining actions.

There is no "correct" number of actions to perform in a single bulk
call. You should experiment with different settings to find the optimum
size for your particular workload.

If using the HTTP API, make sure that the client does not send HTTP
chunks, as this will slow things down.

[float]
[[bulk-versioning]]
=== Versioning

Each bulk item can include the version value using the
`_version`/`version` field. It automatically follows the behavior of the
index / delete operation based on the `_version` mapping. It also
support the `version_type`/`_version_type` (see <<index-versioning, versioning>>)

[float]
[[bulk-routing]]
=== Routing

Each bulk item can include the routing value using the
`_routing`/`routing` field. It automatically follows the behavior of the
index / delete operation based on the `_routing` mapping.

[float]
[[bulk-parent]]
=== Parent

Each bulk item can include the parent value using the `_parent`/`parent`
field. It automatically follows the behavior of the index / delete
operation based on the `_parent` / `_routing` mapping.

[float]
[[bulk-timestamp]]
=== Timestamp

Each bulk item can include the timestamp value using the
`_timestamp`/`timestamp` field. It automatically follows the behavior of
the index operation based on the `_timestamp` mapping.

[float]
[[bulk-ttl]]
=== TTL

Each bulk item can include the ttl value using the `_ttl`/`ttl` field.
It automatically follows the behavior of the index operation based on
the `_ttl` mapping.

[float]
[[bulk-consistency]]
=== Write Consistency

When making bulk calls, you can require a minimum number of active
shards in the partition through the `consistency` parameter. The values
allowed are `one`, `quorum`, and `all`. It defaults to the node level
setting of `action.write_consistency`, which in turn defaults to
`quorum`.

For example, in a N shards with 2 replicas index, there will have to be
at least 2 active shards within the relevant partition (`quorum`) for
the operation to succeed. In a N shards with 1 replica scenario, there
will need to be a single shard active (in this case, `one` and `quorum`
is the same).

[float]
[[bulk-refresh]]
=== Refresh

The `refresh` parameter can be set to `true` in order to refresh the relevant
primary and replica shards immediately after the bulk operation has occurred
and make it searchable, instead of waiting for the normal refresh interval to
expire. Setting it to `true` can trigger additional load, and may slow down
indexing. Due to its costly nature, the `refresh` parameter is set on the bulk request level
and is not supported on each individual bulk item.

[float]
[[bulk-update]]
=== Update

When using `update` action `_retry_on_conflict` can be used as field in
the action itself (not in the extra payload line), to specify how many
times an update should be retried in the case of a version conflict.

The `update` action payload, supports the following options: `doc`
(partial document), `upsert`, `doc_as_upsert`, `script`, `params` (for
script), `lang` (for script). See update documentation for details on
the options. Curl example with update actions:

[source,js]
--------------------------------------------------
{ "update" : {"_id" : "1", "_type" : "type1", "_index" : "index1", "_retry_on_conflict" : 3} }
{ "doc" : {"field" : "value"} }
{ "update" : { "_id" : "0", "_type" : "type1", "_index" : "index1", "_retry_on_conflict" : 3} }
{ "script" : "ctx._source.counter += param1", "lang" : "js", "params" : {"param1" : 1}, "upsert" : {"counter" : 1}}
{ "update" : {"_id" : "2", "_type" : "type1", "_index" : "index1", "_retry_on_conflict" : 3} }
{ "doc" : {"field" : "value"}, "doc_as_upsert" : true }
--------------------------------------------------

[float]
[[bulk-security]]
=== Security

See <<url-access-control>>
