buffer

The buffer output plugin buffers and re-labels events. This plugin is similar to out_relabel, but uses buffer.

It is included in Fluentd's core (since v1.18.0).

Example Configuration

<source>
  @type udp
  @label @buffer
  tag foo.udp
  <parse>
    @type none
  </parse>
</source>

<label @buffer>
  <match **>
    @type buffer
    @label @ROOT
    <buffer>
      path /path/to/buffer
    </buffer>
  </match>
</label>

<match foo.**>
  @type stdout
</match>

In the above example, events ingested by in_udp are once stored in the buffer of this plugin, then re-routed and output by out_stdout.

Supported Modes

• Synchronous Buffered

See also: Output Plugin Overview

Plugin Helpers

• event_emitter

Parameters

Common Parameters

@type (required)

The value must be buffer.

@label (required)

type	default	version
string	nil	1.18.0

Specifies the label to re-route.

Note: You can specify @ROOT to re-route to the root.

<buffer> Section

path (required)

type	default	version
string	required parameter	1.18.0

@type

type	default	version
string	file	1.18.0

Overwrites the default value in this plugin.

chunk_keys

type	default	version
array	tag	1.18.0

Overwrites the default value in this plugin.

flush_mode

type	default	version
enum	interval	1.18.0

Overwrites the default value in this plugin.

flush_interval

type	default	version
integer	10	1.18.0

Overwrites the default value in this plugin.

Common Buffer / Output parameters

In addition, you can configure other common settings. Please see the followings for details.

• Buffer Section Configurations

• Buffer Plugin Overview

• Output Plugin Overview

If this article is incorrect or outdated, or omits critical information, please let us know.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