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Cribl LogStream Documentation

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Publish Metrics


The Publish Metrics Function extracts, formats, and outputs metrics from events.


Filter: Filter expression (JS) that selects data to be fed through the Function. Defaults to true, meaning that all events will be evaluated.

Description: Simple description about this Function. Defaults to empty.

Final: If true, stops data from being fed to downstream Functions. Defaults to No.

Metrics: List of metrics from event to extract and format. Formatted metrics can be used by a destination to pass metrics to a metrics aggregation platform.

  • Event field name: The name of the field in event containing the metric value.

  • Metric name expression: JavaScript expression to evaluate metric field name. Defaults to the Event Field Name value.


The JavaScript expression will evaluate the metric field name only after the metrics are processed for transport to the Destination. While in the processing Pipeline, the metric name expression appears as a literal.

  • Metric type: Select Counter, Timer, or Gauge (the default).

Dimensions: Optional list of dimensions to associate with every extracted metric value. If this Function is used to process output from the Aggregations Function, leave this field blank, because dimensions will be automatically discovered. Defaults to !_* *.


Dimensions supports wildcards and negated terms. When you use negated terms, the list is order-sensitive. E.g., !foobar before foo* means "All fields that start with foo, except foobar." However, !foo* before * means "All fields, except for those that start with foo."

Overwrite: If true, overwrite previous metric specs; otherwise, append. Defaults to No.


Scenario A:

Assume we're working with AWS VPC Flowlog events that have the following structure:

version account_id interface_id srcaddr dstaddr srcport dstport protocol packets bytes start end action log_status

For example:

2 99999XXXXX eni-02f03c2880e4aaa3 9999 63030 6 6556 262256 1554562460 1554562475 ACCEPT OK

... and we want to use values of packets and bytes as metrics across these dimensions: action, interface_id, and dstaddr.

To reference the packets and bytes fields by name, as ‘packets’ and ‘bytes’, our Pipeline will need a Parser Function before the Publish Metrics Function.

Parser Function

Filter: Set as needed
Operation mode: Extract
Type: Extended Log File Format (automatically set when specifying a library)
Library: AWS VPC Flow Logs
Source: _raw
(No need to specify any other fields.)

Publish Metrics Function

Below, the metric_name prefix was arbitrarily chosen. Because there is no JavaScript expression to evaluate – i.e. this is literal text – the strings specified for the Metric name expression will be identical to those in the final metrics data sent to the Destination. See Raw Output below.


Event Field NaLme

Metric Name Expression

Metric Type







action interface_id dstaddr

All specified dimension names must align with those from the original event. When you preview the Function's output, the metrics and dimensions will all have special highlighting to separate them from other fields. Additional highlighting is used to differentiate the metrics from the dimensions. (If one or more metrics/dimensions are not highlighted as expected, check the Function's configuration.)

Raw Output




Compatible Destinations

All text after the # symbol represents the dimensions as key-value pairs. In order for dimension data to be included in metrics, the Destination type cannot be standard StatsD. However, StatsD Extended, Splunk, and Graphite do support dimensions.

  "action": "REJECT",
  "interface_id": "eni-02f03c2880e4aaa3",
  "dstaddr": "",   
  "metric_name.bytes": 262256,
  "metric_name.packets": 6556,

Scenario B:

Assume that we want to extract some metrics from specific fields in PANOS logs, whose events have the following structure:

future_use_0,receive_time, serial_number, type, threat_content_type, future_use_1, generated_time, source_ip, destination_ip, nat_source_ip, nat_destination_ip, rule_name, source_user, destination_user, application, virtual_system, source_zone, destination_zone, inbound_interface, outbound_interface, log_action, future_use_2, session_id, repeat_count, source_port, destination_port, nat_source_port, nat_destination_port, flags, protocol, action, bytes, bytes_sent, bytes_received, packets, start_time, elapsed_time, category, future_use_3, sequence_number, action_flags, source_location, destination_location, future_use_4, packets_sent, packets_received, session_end_reason, device_group_hierarchy_level_1, device_group_hierarchy_level_2, device_group_hierarchy_level_3, device_group_hierarchy_level_4, virtual_system_name, device_name, action_source, source_vm_uuid, destination_vm_uuid, tunnel_id_imsi, monitor_tag_imei, parent_session_id, parent_start_time, tunnel_type, sctp_association_id, sctp_chunks, sctp_chunks_sent, sctp_chunks_received

For example:

Jan 10 10:19:15 1,2019/01/10 10:19:15,001234567890002,TRAFFIC,drop,2304,2019/01/10 10:19:15,,,,,InternalServer,,,not-applicable,vsys1,inside,z1-FW-Transit,ethernet1/2,,All traffic,2019/01/10 10:19:15,0,1,63712,443,0,0,0x0,udp,deny,60,60,0,1,2019/01/10 10:19:15,0,any,0,0123456789,0x0,Netherlands,,0,1,0,policy-deny,0,0,0,0,,DMZ-internal,from-policy,,,0,,0,,N/A,0,0,0,0,1202585d-b4d5-5b4c-aaa2-d80d77ba456e,0

Our goal is to use the four values of bytes_sent, bytes_received, packets_sent, andpackets_received as metrics across these dimensions: destination_ip, inbound_interface, outbound_interface, and destination_port.

Here again, our Pipeline will need a Parser Function before the Publish Metrics Function.

Parser Function

Filter: Set as needed
Operation mode: Extract
Type: Extended Log File Format (automatically set when specifying a Library)
Library: Palo Alto Traffic
Source: _raw
(No need to specify any other fields.)

Publish Metrics Function

Set up the Publish Metrics Function as follows.

Event Field NameMetric Name ExpressionMetric Type
Added Dimensions

destination_ip, inbound_interface, outbound_interface, destination_port

Raw Output

metric.|c|#destination_ip:,inbound_interface:ethernet1/2,destination_port:443 metric.|c|#destination_ip:,inbound_interface:ethernet1/2,destination_port:443 metric.|c|#destination_ip:,inbound_interface:ethernet1/2,destination_port:443 metric.|c|#destination_ip:,inbound_interface:ethernet1/2,destination_port:443

Here again, all text after the # symbol represents the dimensions as key-value pairs. (See the Compatible Destinations note above.) Unlike the first example, this example uses JavaScript expressions, which you can see evaluated in the raw output where the ${host} has been converted to

Updated 6 days ago

Publish Metrics

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