Logstash moduleedit

The logstash module parse logstash regular logs and the slow log, it will support the plain text format and the JSON format (--log.format json). The default is the plain text format.

When you run the module, it performs a few tasks under the hood:

  • Sets the default paths to the log files (but don’t worry, you can override the defaults)
  • Makes sure each multiline log event gets sent as a single event
  • Uses ingest node to parse and process the log lines, shaping the data into a structure suitable for visualizing in Kibana
  • Deploys dashboards for visualizing the log data

The logstash module has two filesets:

  • The log fileset collects and parses the logs that Logstash writes to disk.
  • The slowlog fileset parses the logstash slowlog.

For the slowlog fileset, make sure to configure the Logstash slowlog option.

Compatibilityedit

The Logstash log fileset was tested with logs from Logstash 5.6 and 6.0.

The Logstash slowlog fileset was tested with logs from Logstash 5.6 and 6.0

Set up and run the moduleedit

Important

If you’ve secured Elasticsearch and Kibana, you need to configure the username and password options in the Elasticsearch output before setting up and running the module. See Configure the Elasticsearch output.

Before doing these steps, verify that Elasticsearch and Kibana are running and that Elasticsearch is ready to receive data from Filebeat.

To set up and run the module:

  1. Enable the module:

    ./filebeat modules enable logstash

    The modules enable command enables the logstash config defined in the modules.d directory. See Specify which modules to run for other ways to enable modules.

    To see a list of enabled and disabled modules, run:

    ./filebeat modules list
  2. Set up the initial environment:

    ./filebeat setup -e

    The setup command loads the recommended index template for writing to Elasticsearch and deploys the sample dashboards for visualizing the data in Kibana. This is a one-time setup step.

    The -e flag is optional and sends output to standard error instead of syslog.

  3. Run Filebeat:

    ./filebeat -e

    If the module is configured correctly, you’ll see INFO Harvester started messages for each file specified in the config.

    If your logs aren’t in the default location, see Configure the moduleedit, then run Filebeat after you’ve configured the module.

    Note

    Depending on how you’ve installed Filebeat, you might see errors related to file ownership or permissions when you try to run Filebeat modules. See Config File Ownership and Permissions in the Beats Platform Reference if you encounter errors related to file ownership or permissions.

  4. Explore your data in Kibana:

    1. Open your browser and navigate to the Dashboard overview in Kibana: http://localhost:5601/app/kibana#/dashboards. Replace localhost with the name of the Kibana host.
    2. If security is enabled, log in with the Kibana username and password that you used when you set up security.
    3. Enter logstash in the search box, then open a dashboard and explore the visualizations for your parsed logs.

      Tip

      If you don’t see data in Kibana, try changing the date range to a larger range. By default, Kibana shows the last 15 minutes.

Example dashboardsedit

This module comes with two sample dashboards.

./images/kibana-logstash-log.png
./images/kibana-logstash-slowlog.png

Configure the moduleedit

You can further refine the behavior of the logstash module by specifying variable settings in the modules.d/logstash.yml file, or overriding settings at the command line.

The following example shows how to set paths in the modules.d/logstash.yml file to override the default paths for Logstash logs and set the format to json

- module: logstash
  log:
    enabled: true
    var.paths: ["/path/to/log/logstash.log*"]
    format: json
  slowlog:
    enabled: true
    var.paths: ["/path/to/log/logstash-slowlog.log*"]
    format: json

To specify the same settings at the command line, you use:

./filebeat --modules logstash -M "logstash.log.var.paths=[/path/to/log/logstash/logstash-server.log*]" -M "logstash.slowlog.var.paths=[/path/to/log/logstash/logstash-slowlog.log*]"

Variable settingsedit

The logstash module provides the following settings for configuring the behavior of the module. Each fileset has separate settings.

If you don’t specify variable settings, the logstash module uses the defaults.

For more information, see Specify variable settings. Also see Advanced settings.

Tip

When you specify a setting at the command line, remember to prefix the setting with the module name, for example, logstash.log.var.paths instead of log.var.paths.

log fileset settingsedit

var.paths
An array of paths that specify where to look for the log files. If left empty, Filebeat will choose the paths depending on your operating systems.
var.format
The configured Logstash log format. Possible values are: json or plain. The default is plain.

slowlog fileset settingsedit

var.paths
An array of paths that specify where to look for the log files. If left empty, Filebeat will choose the paths depending on your operating systems.
var.format
The configured Logstash log format. Possible values are: json or plain. The default is plain.

Fieldsedit

For a description of each field in the module, see the exported fields section.