Metrics filter plugin
editMetrics filter plugin
edit- Plugin version: v4.0.7
- Released on: 2021-01-20
- Changelog
For other versions, see the Versioned plugin docs.
Installation
editFor plugins not bundled by default, it is easy to install by running bin/logstash-plugin install logstash-filter-metrics
. See Working with plugins for more details.
Getting Help
editFor questions about the plugin, open a topic in the Discuss forums. For bugs or feature requests, open an issue in Github. For the list of Elastic supported plugins, please consult the Elastic Support Matrix.
Description
editThe metrics filter is useful for aggregating metrics.
Elasticsearch 2.0 no longer allows field names with dots. Version 3.0 of the metrics filter plugin changes behavior to use nested fields rather than dotted notation to avoid colliding with versions of Elasticsearch 2.0+. Please note the changes in the documentation (underscores and sub-fields used).
For example, if you have a field response
that is
a http response code, and you want to count each
kind of response, you can do this:
filter { metrics { meter => [ "http_%{response}" ] add_tag => "metric" } }
Metrics are flushed every 5 seconds by default or according to
flush_interval
. Metrics appear as
new events in the event stream and go through any filters
that occur after as well as outputs.
In general, you will want to add a tag to your metrics and have an output explicitly look for that tag.
The event that is flushed will include every meter and timer metric in the following way:
meter
values
editFor a meter => "thing"
you will receive the following fields:
- "[thing][count]" - the total count of events
- "[thing][rate_1m]" - the per-second event rate in a 1-minute sliding window
- "[thing][rate_5m]" - the per-second event rate in a 5-minute sliding window
- "[thing][rate_15m]" - the per-second event rate in a 15-minute sliding window
timer
values
editFor a timer => { "thing" => "%{duration}" }
you will receive the following fields:
- "[thing][count]" - the total count of events
- "[thing][rate_1m]" - the per-second average value in a 1-minute sliding window
- "[thing][rate_5m]" - the per-second average value in a 5-minute sliding window
- "[thing][rate_15m]" - the per-second average value in a 15-minute sliding window
- "[thing][min]" - the minimum value seen for this metric
- "[thing][max]" - the maximum value seen for this metric
- "[thing][stddev]" - the standard deviation for this metric
- "[thing][mean]" - the mean for this metric
-
"[thing][pXX]" - the XXth percentile for this metric (see
percentiles
)
The default lengths of the event rate window (1, 5, and 15 minutes)
can be configured with the rates
option.
Example: Computing event rate
editFor a simple example, let’s track how many events per second are running through logstash:
input { generator { type => "generated" } } filter { if [type] == "generated" { metrics { meter => "events" add_tag => "metric" } } } output { # only emit events with the 'metric' tag if "metric" in [tags] { stdout { codec => line { format => "rate: %{[events][rate_1m]}" } } } }
Running the above:
% bin/logstash -f example.conf rate: 23721.983566819246 rate: 24811.395722536377 rate: 25875.892745934525 rate: 26836.42375967113
We see the output includes our events' 1-minute rate.
In the real world, you would emit this to graphite or another metrics store, like so:
output { graphite { metrics => [ "events.rate_1m", "%{[events][rate_1m]}" ] } }
Metrics Filter Configuration Options
editThis plugin supports the following configuration options plus the Common Options described later.
Setting | Input type | Required |
---|---|---|
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
Also see Common Options for a list of options supported by all filter plugins.
clear_interval
edit- Value type is number
-
Default value is
-1
The clear interval, when all counters are reset.
If set to -1, the default value, the metrics will never be cleared. Otherwise, should be a multiple of 5s.
flush_interval
edit- Value type is number
-
Default value is
5
The flush interval, when the metrics event is created. Must be a multiple of 5s.
ignore_older_than
edit- Value type is number
-
Default value is
0
Don’t track events that have @timestamp
older than some number of seconds.
This is useful if you want to only include events that are near real-time in your metrics.
For example, to only count events that are within 10 seconds of real-time, you would do this:
filter { metrics { meter => [ "hits" ] ignore_older_than => 10 } }
meter
edit- Value type is array
-
Default value is
[]
syntax: meter => [ "name of metric", "name of metric" ]
percentiles
edit- Value type is array
-
Default value is
[1, 5, 10, 90, 95, 99, 100]
The percentiles that should be measured and emitted for timer values.
Common Options
editThe following configuration options are supported by all filter plugins:
Setting | Input type | Required |
---|---|---|
No |
||
No |
||
No |
||
No |
||
No |
||
No |
||
No |
add_field
edit- 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 { metrics { add_field => { "foo_%{somefield}" => "Hello world, from %{host}" } } }
# You can also add multiple fields at once: filter { metrics { 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_tag
edit- 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 { metrics { add_tag => [ "foo_%{somefield}" ] } }
# You can also add multiple tags at once: filter { metrics { 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).
enable_metric
edit- Value type is boolean
-
Default value is
true
Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.
id
edit- Value type is string
- There is no default value for this setting.
Add a unique ID
to the plugin configuration. If no ID is specified, Logstash will generate one.
It is strongly recommended to set this ID in your configuration. This is particularly useful
when you have two or more plugins of the same type, for example, if you have 2 metrics filters.
Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.
filter { metrics { id => "ABC" } }
periodic_flush
edit- Value type is boolean
-
Default value is
false
Call the filter flush method at regular interval. Optional.
remove_field
edit- Value type is array
-
Default value is
[]
If this filter is successful, remove arbitrary fields from this event. Fields names can be dynamic and include parts of the event using the %{field} Example:
filter { metrics { remove_field => [ "foo_%{somefield}" ] } }
# You can also remove multiple fields at once: filter { metrics { 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_tag
edit- 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 { metrics { remove_tag => [ "foo_%{somefield}" ] } }
# You can also remove multiple tags at once: filter { metrics { 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.