example.rst

Examples

• Reliable log forwarding (active-backup)
• Reliable log forwarding (active-active)

Reliable log forwarding (active-backup)

This example assumes following network:

                   active log server
                   +--------+
                +--> fluent | 192.168.0.1
front server    |  +--------+
+--------+      |
| fluent -------+
+--------+      |  backup log server
                |  +--------+
                +--> fluent | 192.168.0.2
                   +--------+

On the front servers, use following configuration:

<match PATTERN>
  type tcp
  host 192.168.0.1
  port 24224

  # use file buffer to buffer events on disks.
  buffer_type file
  buffer_path /var/log/fluent/buffer/myforward

  # use longer flush_interval to reduce CPU usage.
  # this is trade-off of latency.
  flush_interval 60s

  # use secondary host
  <secondary>
    host 192.168.0.2
    port 24224
  </secondary>
</match>

On the log servers, add tcp input not exists:

<source>
  type tcp
  port 24224
</source>

Reliable log forwarding (active-active)

You can use active-active formation by using following configuration on the front servers:

<match PATTERN>
  # use 'roundrobin' output plugin
  type roundrobin

  <store>
    type tcp
    host 192.168.0.1
    port 24224

    buffer_type file
    buffer_path /var/log/fluent/buffer/myforward-1
    flush_interval 60s

    <secondary>
      host 192.168.0.2
      port 24224
    </secondary>
  </store>

  <store>
    type tcp
    host 192.168.0.2
    port 24224

    buffer_type file
    buffer_path /var/log/fluent/buffer/myforward-2
    flush_interval 60s

    <secondary>
      host 192.168.0.1
      port 24224
    </secondary>
  </store>
</match>