Output Plugin Overview

Fluentd has 6 types of plugins: Input, Parser, Filter, Output, Formatter and Buffer. This article gives an overview of Filter Plugin.

Overview

There are three types of output plugins: Non-Buffered, Buffered, and Time Sliced.

• Non-Buffered output plugins do not buffer data and immediately write out results.
• Buffered output plugins maintain a queue of chunks (a chunk is a collection of events), and its behavior can be tuned by the "chunk limit" and "queue limit" parameters (See the diagram below).
• Time Sliced output plugins are in fact a type of Bufferred plugin, but the chunks are keyed by time (See the diagram below).

The output plugin's buffer behavior (if any) is defined by a separate Buffer plugin. Different buffer plugins can be chosen for each output plugin. Some output plugins are fully customized and do not use buffers.

secondary output

At Buffered output plugin, the user can specify <secondary> with any output plugin in <match> configuration. If the retry count exceeds the buffer's retry_limit (and the retry limit has not been disabled via disable_retry_limit), then buffered chunk is output to <secondary> output plugin.

<secondary> is useful for backup when destination servers are unavailable, e.g. forward, mongo and other plugins. We strongly recommend out_file plugin for <secondary>.

List of Non-Buffered Output Plugins

• out_copy
• out_null
• out_roundrobin
• out_stdout

List of Buffered Output Plugins

• out_exec_filter
• out_forward
• out_mongo or out_mongo_replset

List of Time Sliced Output Plugins

• out_exec
• out_file
• out_s3
• out_webhdfs

Other Plugins

Please refer to this list of available plugins to find out about other Output plugins.

• others