This plugin is designed to count occurrences of unique values in a specified key and pass them through as counts either as a re-emit or by directly incrementing a specified redis hash. As it's a buffered plugin it will write or re-emit at a (tunable) sane pace.

Given a set of input like

important.thing.12086 { 'time': 1413544800, 'event': 'seen', 'user_id': 12345 }
important.thing.1337 { 'time': 1413544890, 'event': 'seen', 'user_id': 1337 }
important.thing.12086 { 'time': 1413544830, 'event': 'liked', 'user_id': 33864 }
important.thing.12086 { 'time': 1413544860, 'event': 'clicked', 'user_id': 12345, url: 'http://example.com/promote?someParam=something' }
important.thing.12086 { 'time': 1413544890, 'event': 'seen', 'user_id': 40555 }
important.thing.12086 { 'time': 1413544860, 'event': 'clicked', 'user_id': 12345, url: 'http://example.com/promote?someParam=somethingElse' }

With a conf like

<match important.thing.*>
    type eventcounter
    count_key event
    input_tag_exclude important.thing.

    capture_extra_if url
    capture_extra_replace \?.*$

    emit_only true
    emit_tag event.counts
</match>

You would get

event.counts { 12086: { 'seen': 2, 'liked': 1, 'clicked:http://example.com/promote': 2 } }
event.counts { 1337: { 'seen': 1 } }

If the plugin is not set to emit only, and redis is properly configured each of those counts increment a key in a hash specified by redis_output_key:tag count_key

##Installation

OSX

/opt/td-agent/embedded/bin/gem install fluent-plugin-eventcounter

or

fluent-gem install fluent-plugin-eventcounter

• count_key (required)

  • The key within the record to count unique instances of
    • eg. event

• input_tag_exclude (optional)

  • A pattern to exclude from the incoming tag
    • default: ''

• emit_only (optional) - boolean

  • Skip redis and re-emit using emit_to
    • default: false

• emit_to (optional) - string

  • Tag to re-emit with
    • default: debug.events

• capture_extra_if (optional)

  • An additional field to attach to the captured key
    • default: nil

• capture_extra_replace (optional)

  • A regular expression to replace a portion of the extra capture. (note: this is passed as a string and parsed as a regex so be aware that you may need to escape reserved characters to preserve their meaning.)
    • default: ''

• redis_host (optional) - string

  • Host address of the redis server
    • default: localhost

• redis_port (optional)

  • Port of the redis server ()
    • default: 6379

• redis_password (optional)

  • Password for the redis server
    • default: nil

• redis_sentinels (optional) - array

  • A list of sentinel hosts for failover
    • default: []

• redis_master_group_name (optional) - string

  • Sentinel master group name
    • default: mymaster

• redis_db_number (optional)

  • Redis DB (not used if redis_sentinels is set)
    • default: 0

• redis_output_key (optional)

  • The key to prefix against the tag
    • default: ''

• flush_interval (optional)
  • Provided from Fluent::BufferedOutput time in seconds between flushes
    • default: 60