Windows Event logs (winevtlog)

Supported event types: logs

The Windows Event logs (winevtlog) input plugin lets you read Windows Event logs with the API from winevt.h.

Configuration parameters

The plugin supports the following configuration parameters:

Key	Description	Default
channels	A comma-separated list of channels to read from.	none
db	Optional. Set the path to save the read offsets.	none
event_data_as_map	Optional. Emit EventData as a named map built from provider metadata instead of string inserts. Requires event_template_cache_size greater than zero.	false
event_query	Specify XML query for filtering events.	*
event_template_cache_size	Optional. Maximum number of provider event templates cached when event_data_as_map is enabled.	256
ignore_missing_channels	Optional. Whether to ignore event channels not present in the event log, and continue running with subscribed channels.	false
interval_nsec	Optional. Set the polling interval for each channel. (nanoseconds)	0
interval_sec	Optional. Set the polling interval for each channel.	1
read_existing_events	Optional. Whether to read existing events from head or tailing events at last on subscribing.	false
read_limit_per_cycle	Specify read limit per cycle.	512KiB
remote.domain	Specify domain name of remote access for Windows EventLog.	none
remote.password	Specify password of remote access for Windows EventLog.	none
remote.server	Specify server name of remote access for Windows EventLog.	none
remote.username	Specify user name of remote access for Windows EventLog.	none
reconnect.base_ms	Base reconnect delay in milliseconds after a subscription failure.	500
reconnect.max_ms	Maximum reconnect delay in milliseconds.	30000
reconnect.multiplier	Backoff multiplier applied between reconnect attempts.	2.0
reconnect.jitter_pct	Jitter percentage applied to the reconnect delay to avoid synchronized retries.	20
reconnect.max_retries	Maximum number of reconnect attempts before the channel stops retrying.	8
render_event_as_text	Optional. Render the Windows EventLog event as newline-separated key=value text. Mutually exclusive with render_event_as_xml.	false
render_event_as_xml	Optional. Render the Windows EventLog event as XML, including the System and Message fields. Mutually exclusive with render_event_as_text.	false
render_event_text_key	Optional. Record key name used to store the rendered text when render_event_as_text is enabled.	log
string_inserts	Optional. Whether to include string inserts in output records.	true
threaded	Indicates whether to run this input in its own thread.	false
use_ansi	Optional. Use ANSI encoding on eventlog messages. If you have issues receiving blank strings with old Windows versions (Server 2012 R2), setting this to true might solve the problem.	false

If db isn't set, the plugin will tail channels on each startup.

Configuration examples

Configuration file

Here is a minimum configuration example.

fluent-bit.yaml

pipeline:
  inputs:
    - name: winevtlog
      channels: Setup,Windows PowerShell
      interval_sec: 1
      db: winevtlog.sqlite

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

[INPUT]
  Name         winevtlog
  Channels     Setup,Windows PowerShell
  Interval_Sec 1
  DB           winevtlog.sqlite

[OUTPUT]
  Name   stdout
  Match  *

Some Windows Event Log channels, like Security, require administrative privilege for reading. In this case, you must run Fluent Bit as an administrator.

The default value of read_limit_per_cycle is 512KiB.

512 KiB(= 0x7ffff = 512 * 1024 * 1024) isn't equal to 512 KB (= 512 * 1000 * 1000). To increase events per second on this plugin, specify larger value than 512 KiB.

Query languages for event_query parameter

The event_query parameter can be used to specify the XML query for filtering Windows EventLog during collection. The supported query types are XPath and XML Query. For further details, refer to Microsoft's documentation.

Render events as text

When render_event_as_text is set to true, each event is rendered as a newline-separated key=value string and stored under the key specified by render_event_text_key. This mode is mutually exclusive with render_event_as_xml—enabling both causes the plugin to exit with an error.

fluent-bit.yaml

pipeline:
  inputs:
    - name: winevtlog
      channels: Setup,Windows PowerShell
      db: winevtlog.sqlite
      render_event_as_text: true
      render_event_text_key: log

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

[INPUT]
  Name                   winevtlog
  Channels               Setup,Windows PowerShell
  DB                     winevtlog.sqlite
  Render_Event_As_Text   true
  Render_Event_Text_Key  log

[OUTPUT]
  Name   stdout
  Match  *

Emit EventData as a map

By default, the EventData values of an event are emitted as string inserts. When event_data_as_map is set to true, the plugin uses the event provider's metadata to emit EventData as a named map, so each value is keyed by its field name instead of appearing as a positional string insert.

This mode caches provider event templates. Use event_template_cache_size to set the maximum number of cached templates. The value must be greater than zero when event_data_as_map is enabled, otherwise the plugin exits with an error.

fluent-bit.yaml

pipeline:
  inputs:
    - name: winevtlog
      channels: Setup,Windows PowerShell
      db: winevtlog.sqlite
      event_data_as_map: true
      event_template_cache_size: 256

  outputs:
    - name: stdout
      match: '*'

fluent-bit.conf

[INPUT]
  Name                       winevtlog
  Channels                   Setup,Windows PowerShell
  DB                         winevtlog.sqlite
  Event_Data_As_Map          true
  Event_Template_Cache_Size  256

[OUTPUT]
  Name   stdout
  Match  *

Command line

If you want to do a test, you can run this plugin from the command line:

fluent-bit -i winevtlog -p 'channels=Setup' -p 'read_existing_events=true' -o stdout

The winevtlog plugin will tail channels on each startup. If you want to confirm whether this plugin is working or not, specify the -p 'read_existing_events=true' parameter.