throttleedit

Note

This is a community-maintained plugin!

The throttle filter is for throttling the number of events received. The filter is configured with a lower bound, the before_count, and upper bound, the after_count, and a period of time. All events passing through the filter will be counted based on a key. As long as the count is less than the before_count or greater than the after_count, the event will be "throttled" which means the filter will be considered successful and any tags or fields will be added.

For example, if you wanted to throttle events so you only receive an event after 2 occurrences and you get no more than 3 in 10 minutes, you would use the configuration:

period => 600
before_count => 3
after_count => 5

Which would result in:

event 1 - throttled (successful filter, period start)
event 2 - throttled (successful filter)
event 3 - not throttled
event 4 - not throttled
event 5 - not throttled
event 6 - throttled (successful filter)
event 7 - throttled (successful filter)
event x - throttled (successful filter)
period end
event 1 - throttled (successful filter, period start)
event 2 - throttled (successful filter)
event 3 - not throttled
event 4 - not throttled
event 5 - not throttled
event 6 - throttled (successful filter)
...

Another example is if you wanted to throttle events so you only receive 1 event per hour, you would use the configuration:

period => 3600
before_count => -1
after_count => 1

Which would result in:

event 1 - not throttled (period start)
event 2 - throttled (successful filter)
event 3 - throttled (successful filter)
event 4 - throttled (successful filter)
event x - throttled (successful filter)
period end
event 1 - not throttled (period start)
event 2 - throttled (successful filter)
event 3 - throttled (successful filter)
event 4 - throttled (successful filter)
...

A common use case would be to use the throttle filter to throttle events before 3 and after 5 while using multiple fields for the key and then use the drop filter to remove throttled events. This configuration might appear as:

filter {
  throttle {
    before_count => 3
    after_count => 5
    period => 3600
    key => "%{host}%{message}"
    add_tag => "throttled"
  }
  if "throttled" in [tags] {
    drop { }
  }
}

Another case would be to store all events, but only email non-throttled events so the op’s inbox isn’t flooded with emails in the event of a system error. This configuration might appear as:

filter {
  throttle {
    before_count => 3
    after_count => 5
    period => 3600
    key => "%{message}"
    add_tag => "throttled"
  }
}
output {
  if "throttled" not in [tags] {
    email {
        from => "logstash@mycompany.com"
        subject => "Production System Alert"
        to => "ops@mycompany.com"
        via => "sendmail"
        body => "Alert on %{host} from path %{path}:\n\n%{message}"
        options => { "location" => "/usr/sbin/sendmail" }
    }
  }
  elasticsearch_http {
    host => "localhost"
    port => "19200"
  }
}

The event counts are cleared after the configured period elapses since the first instance of the event. That is, all the counts don’t reset at the same time but rather the throttle period is per unique key value.

Mike Pilone (@mikepilone)

 

Synopsisedit

This plugin supports the following configuration options:

Required configuration options:

throttle {
    key => ...
}

Available configuration options:

Detailsedit

 

add_fieldedit

  • Value type is hash
  • Default value is {}

If this filter is successful, add any arbitrary fields to this event. Field names can be dynamic and include parts of the event using the %{field}.

Example:

filter {
  throttle {
    add_field => { "foo_%{somefield}" => "Hello world, from %{host}" }
  }
}
# You can also add multiple fields at once:
filter {
  throttle {
    add_field => {
      "foo_%{somefield}" => "Hello world, from %{host}"
      "new_field" => "new_static_value"
    }
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add field foo_hello if it is present, with the value above and the %{host} piece replaced with that value from the event. The second example would also add a hardcoded field.

add_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, add arbitrary tags to the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

filter {
  throttle {
    add_tag => [ "foo_%{somefield}" ]
  }
}
# You can also add multiple tags at once:
filter {
  throttle {
    add_tag => [ "foo_%{somefield}", "taggedy_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would add a tag foo_hello (and the second example would of course add a taggedy_tag tag).

after_countedit

  • Value type is number
  • Default value is -1

Events greater than this count will be throttled. Setting this value to -1, the default, will cause no messages to be throttled based on the upper bound.

before_countedit

  • Value type is number
  • Default value is -1

Events less than this count will be throttled. Setting this value to -1, the default, will cause no messages to be throttled based on the lower bound.

keyedit

  • This is a required setting.
  • Value type is string
  • There is no default value for this setting.

The name to use in configuration files. The key used to identify events. Events with the same key will be throttled as a group. Field substitutions are allowed, so you can combine multiple fields.

max_countersedit

  • Value type is number
  • Default value is 100000

The maximum number of counters to store before the oldest counter is purged. Setting this value to -1 will prevent an upper bound no constraint on the number of counters and they will only be purged after expiration. This configuration value should only be used as a memory control mechanism and can cause early counter expiration if the value is reached. It is recommended to leave the default value and ensure that your key is selected such that it limits the number of counters required (i.e. don’t use UUID as the key!)

periodedit

  • Value type is string
  • Default value is "3600"

The period in seconds after the first occurrence of an event until the count is reset for the event. This period is tracked per unique key value. Field substitutions are allowed in this value. They will be evaluated when the first event for a given key is seen. This allows you to specify that certain kinds of events throttle for a specific period.

periodic_flushedit

  • Value type is boolean
  • Default value is false

Call the filter flush method at regular interval. Optional.

remove_fieldedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary fields from this event. Example:

filter {
  throttle {
    remove_field => [ "foo_%{somefield}" ]
  }
}
# You can also remove multiple fields at once:
filter {
  throttle {
    remove_field => [ "foo_%{somefield}", "my_extraneous_field" ]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the field with name foo_hello if it is present. The second example would remove an additional, non-dynamic field.

remove_tagedit

  • Value type is array
  • Default value is []

If this filter is successful, remove arbitrary tags from the event. Tags can be dynamic and include parts of the event using the %{field} syntax.

Example:

filter {
  throttle {
    remove_tag => [ "foo_%{somefield}" ]
  }
}
# You can also remove multiple tags at once:
filter {
  throttle {
    remove_tag => [ "foo_%{somefield}", "sad_unwanted_tag"]
  }
}

If the event has field "somefield" == "hello" this filter, on success, would remove the tag foo_hello if it is present. The second example would remove a sad, unwanted tag as well.