Versions | v1.0 (td-agent3)

Elasticsearch Output Plugin

The out_elasticsearch Output plugin writes records into Elasticsearch. By default, it creates records by bulk write operation. This means that when you first import records using the plugin, no record is created immediately.

The record will be created when the chunk_keys condition has been met. To change the output frequency, please specify the time in chunk_keys and specify timekey value in conf.

This document doesn't describe all parameters. If you want to know full features, check the Further Reading section.

Table of Contents


Since out_elasticsearch has been included in the standard distribution of td-agent since v3.0.1, td-agent users do not need to install it manually.

If you have installed Fluentd without td-agent, please install this plugin using fluent-gem.

$ fluent-gem install fluent-plugin-elasticsearch

Example Configuration

The following is a simple working configuration. This should serve as a good starting point for most users.

<match my.logs>
  @type elasticsearch
  host localhost
  port 9200
  logstash_format true

For more details on each option, read the section on Parameters.

Plugin helpers


@type (required)

This option must be always elasticsearch.

host (optional)

The hostname of your Elasticsearch node (default: localhost).

port (optional)

The port number of your Elasticsearch node (default: 9200).

hosts (optional)

If you want to connect to more than one Elasticsearch nodes, specify this option in the following format:

hosts host1:port1,host2:port2,host3:port3
# or

If you use this option, the host and port options are ignored.

user, password (optional)

The login credentials to connect to the Elasticsearch node (default: nil)

user fluent
password mysecret

scheme (optional)

Specify https if your Elasticsearch endpoint supports SSL (default: http)

path (optional)

The REST API endpoint of Elasticsearch to post write requests (default: nil)

index_name (optional)

The index name to write events to (default: fluentd).

This option supports the placeholder syntax of Fluentd plugin API. For example, if you want to partition the index by tags, you can specify as below:

index_name fluentd.${tag}

Here is a more practical example which partitions the Elasticsearch index by tags and timestamps:

index_name fluentd.${tag}.%Y%m%d

logstash_format (optional)

With this option set true, Fluentd uses the conventional index name format logstash-%Y.%m.%d (default: false). This option supersedes the index_name option.

@log_level option

The @log_level option allows the user to set different levels of logging for each plugin. The supported log levels are: fatal, error, warn, info, debug, and trace.

Please see the logging article for further details.


You can use %{} style placeholders to escape for URL encoding needed characters.

user %{demo+}
password %{@secret}

are valid configuration.

hosts https://%{j+hn}:%{passw@rd}@host1:443/elastic/,http://host2

are also valid configuration.


user demo+
password @secret

are invalid configuration.

Common Output / Buffer parameters

For common output / buffer parameters, please check the following articles.


Cannot send events to Elasticsearch

A common cause of failure is that you are trying to connect to an Elasticsearch instance with an incompatible version.

For example, td-agent currently bundles the 6.x series of the elasticsearch-ruby library. This means that your Elasticsearch server also needs to be 6.x. You can check the actual version of the client library installed on your system by executing the following command.

# For td-agent users
$ /usr/sbin/td-agent-gem list elasticsearch
# For standalone Fluentd users
$ fluent-gem list elasticsearch

Or, fluent-plugin-elasticsearch v2.11.7 or later, users can inspect version incompatibility with the validate_client_version option:

validate_client_version true

If you get the following error message, please consider to install compatibile elasticsearch client gems:

Detected ES 5 but you use ES client 6.1.0.
Please consider to use 5.x series ES client.

For further details of the version compatibility issue, please read the official manual.

Further Reading

Last updated: 2018-09-25 20:31:56 +0000

Versions | v1.0 (td-agent3)

If this article is incorrect or outdated, or omits critical information, please let us know. Fluentd is a open source project under Cloud Native Computing Foundation (CNCF). All components are available under the Apache 2 License.