Collect Logstash monitoring data using internal collectorsedit

Using internal collectors for Logstash X-Pack monitoring these components:

These pieces live outside of the default Logstash pipeline in a dedicated monitoring pipeline. This configuration ensures that all data and processing has a minimal impact on ordinary Logstash processing. Existing Logstash features, such as the elasticsearch output, can be reused to benefit from its retry policies.

The elasticsearch output that is used by X-Pack monitoring for Logstash is configured exclusively via settings found in logstash.yml. It is not configured by using anything from the Logstash configurations that might also be using their own separate elasticsearch outputs.

The Elasticsearch cluster that is configured for use with X-Pack monitoring for Logstash is expected to be the production cluster. This configuration enables the production Elasticsearch cluster to add metadata (for example, its cluster UUID) to the Logstash monitoring data then route it to the monitoring clusters. For more information about typical monitoring architectures, see How monitoring works in the Elasticsearch Reference.

Collectorsedit

Collectors, as their name implies, collect things. In X-Pack monitoring for Logstash, collectors are just Inputs in the same way that ordinary Logstash configurations provide inputs.

Like X-Pack monitoring for Elasticsearch, each collector can create zero or more monitoring documents. As it is currently implemented, each Logstash node runs two types of collectors: one for node stats and one for pipeline stats.

CollectorData TypesDescription

Node Stats

logstash_stats

Gathers details about the running node, such as memory utilization and CPU usage (for example, GET /_stats).

This runs on every Logstash node with X-Pack monitoring enabled. One common failure is that Logstash directories are copied with their path.data directory included (./data by default), which copies the persistent UUID of the Logstash node along with it. As a result, it generally appears that one or more Logstash nodes are failing to collect monitoring data, when in fact they are all really misreporting as the same Logstash node. Re-use path.data directories only when upgrading Logstash, such that upgraded nodes replace the previous versions.

Pipeline Stats

logstash_state

Gathers details about the node’s running pipelines, which powers the Monitoring Pipeline UI.

Per collection interval, which defaults to 10 seconds (10s), each collector is run. The failure of an individual collector does not impact any other collector. Each collector, as an ordinary Logstash input, creates a separate Logstash event in its isolated monitoring pipeline. The Logstash output then sends the data.

The collection interval can be configured dynamically and you can also disable data collection. For more information about the configuration options for the collectors, see Monitoring Settings.

Unlike X-Pack monitoring for Elasticsearch and Kibana, there is no xpack.monitoring.collection.enabled setting on Logstash. You must use the xpack.monitoring.enabled setting to enable and disable data collection.

If gaps exist in the monitoring charts in Kibana, it is typically because either a collector failed or the monitoring cluster did not receive the data (for example, it was being restarted). In the event that a collector fails, a logged error should exist on the node that attempted to perform the collection.

Outputedit

Like all Logstash pipelines, the purpose of the dedicated monitoring pipeline is to send events to outputs. In the case of X-Pack monitoring for Logstash, the output is always an elasticsearch output. However, unlike ordinary Logstash pipelines, the output is configured within the logstash.yml settings file via the xpack.monitoring.elasticsearch.* settings.

Other than its unique manner of configuration, this elasticsearch output behaves like all elasticsearch outputs, including its ability to pause data collection when issues exist with the output.

It is critical that all Logstash nodes share the same setup. Otherwise, monitoring data might be routed in different ways or to different places.

Default Configurationedit

If a Logstash node does not explicitly define an X-Pack monitoring output setting, the following default configuration is used:

xpack.monitoring.elasticsearch.hosts: [ "http://localhost:9200" ]

All data produced by X-Pack monitoring for Logstash is indexed in the monitoring cluster by using the .monitoring-logstash template, which is managed by the exporters within Elasticsearch.

If you are working with a cluster that has X-Pack security enabled, extra steps are necessary to properly configure Logstash. For more information, see Monitoring Logstash with X-Pack.

When discussing security relative to the elasticsearch output, it is critical to remember that all users are managed on the production cluster, which is identified in the xpack.monitoring.elasticsearch.hosts setting. This is particularly important to remember when you move from development environments to production environments, where you often have dedicated monitoring clusters.

For more information about the configuration options for the output, see Monitoring Settings.

Configure Logstash monitoring with internal collectorsedit

To monitor Logstash nodes:

  1. Specify where to send monitoring data. This cluster is often referred to as the production cluster. For examples of typical monitoring architectures, see How monitoring works.

    To visualize Logstash as part of the Elastic Stack (as shown in Step 6), send metrics to your production cluster. Sending metrics to a dedicated monitoring cluster will show the Logstash metrics under the monitoring cluster.

  2. Verify that the xpack.monitoring.collection.enabled setting is true on the production cluster. If that setting is false, the collection of monitoring data is disabled in Elasticsearch and data is ignored from all other sources.
  3. Configure your Logstash nodes to send metrics by setting the xpack.monitoring.elasticsearch.hosts in logstash.yml. If X-Pack security is enabled, you also need to specify the credentials for the built-in logstash_system user. For more information about these settings, see Monitoring Settings.

    xpack.monitoring.elasticsearch.hosts: ["http://es-prod-node-1:9200", "http://es-prod-node-2:9200"] 
    xpack.monitoring.elasticsearch.username: "logstash_system" 
    xpack.monitoring.elasticsearch.password: "changeme"

    If SSL/TLS is enabled on the production cluster, you must connect through HTTPS. As of v5.2.1, you can specify multiple Elasticsearch hosts as an array as well as specifying a single host as a string. If multiple URLs are specified, Logstash can round-robin requests to these production nodes.

    If X-Pack security is disabled on the production cluster, you can omit these username and password settings.

  4. If SSL/TLS is enabled on the production Elasticsearch cluster, specify the trusted CA certificates that will be used to verify the identity of the nodes in the cluster.

    To add a CA certificate to a Logstash node’s trusted certificates, you can specify the location of the PEM encoded certificate with the certificate_authority setting:

    xpack.monitoring.elasticsearch.ssl.certificate_authority: /path/to/ca.crt

    Alternatively, you can configure trusted certificates using a truststore (a Java Keystore file that contains the certificates):

    xpack.monitoring.elasticsearch.ssl.truststore.path: /path/to/file
    xpack.monitoring.elasticsearch.ssl.truststore.password: password

    Also, optionally, you can set up client certificate using a keystore (a Java Keystore file that contains the certificate):

    xpack.monitoring.elasticsearch.ssl.keystore.path: /path/to/file
    xpack.monitoring.elasticsearch.ssl.keystore.password: password

    Set sniffing to true to enable discovery of other nodes of the Elasticsearch cluster. It defaults to false.

    xpack.monitoring.elasticsearch.sniffing: false
  5. Restart your Logstash nodes.
  6. To verify your X-Pack monitoring configuration, point your web browser at your Kibana host, and select Monitoring from the side navigation. Metrics reported from your Logstash nodes should be visible in the Logstash section. When security is enabled, to view the monitoring dashboards you must log in to Kibana as a user who has the kibana_user and monitoring_user roles.

    Monitoring
Re-enabling Logstash Monitoring After Upgradingedit

When upgrading from older versions of X-Pack, the built-in logstash_system user is disabled for security reasons. To resume monitoring, change the password and re-enable the logstash_system user.

Monitoring settings for internal collectionedit

You can set the following xpack.monitoring settings in logstash.yml to control how monitoring data is collected from your Logstash nodes. However, the defaults work best in most circumstances. For more information about configuring Logstash, see logstash.yml.

General monitoring settingsedit

xpack.monitoring.enabled
Monitoring is disabled by default. Set to true to enable X-Pack monitoring.
xpack.monitoring.elasticsearch.hosts
The Elasticsearch instances that you want to ship your Logstash metrics to. This might be the same Elasticsearch instance specified in the outputs section in your Logstash configuration, or a different one. This is not the URL of your dedicated monitoring cluster. Even if you are using a dedicated monitoring cluster, the Logstash metrics must be routed through your production cluster. You can specify a single host as a string, or specify multiple hosts as an array. Defaults to http://localhost:9200.

If your Elasticsearch cluster is configured with dedicated master-eliglble nodes, Logstash metrics should not be routed to these nodes, as doing so can create resource contention and impact the stability of the Elasticsearch cluster. Therefore, do not include such nodes in xpack.monitoring.elasticsearch.hosts.

xpack.monitoring.elasticsearch.username and xpack.monitoring.elasticsearch.password
If your Elasticsearch is protected with basic authentication, these settings provide the username and password that the Logstash instance uses to authenticate for shipping monitoring data.

Monitoring collection settingsedit

xpack.monitoring.collection.interval
Controls how often data samples are collected and shipped on the Logstash side. Defaults to 10s. If you modify the collection interval, set the xpack.monitoring.min_interval_seconds option in kibana.yml to the same value.

X-Pack monitoring TLS/SSL settingsedit

You can configure the following Transport Layer Security (TLS) or Secure Sockets Layer (SSL) settings. For more information, see Configuring Credentials for Logstash Monitoring.

xpack.monitoring.elasticsearch.ssl.certificate_authority
Optional setting that enables you to specify a path to the .pem file for the certificate authority for your Elasticsearch instance.
xpack.monitoring.elasticsearch.ssl.truststore.path
Optional settings that provide the paths to the Java keystore (JKS) to validate the server’s certificate.
xpack.monitoring.elasticsearch.ssl.truststore.password
Optional settings that provide the password to the truststore.
xpack.monitoring.elasticsearch.ssl.keystore.path
Optional settings that provide the paths to the Java keystore (JKS) to validate the client’s certificate.
xpack.monitoring.elasticsearch.ssl.keystore.password
Optional settings that provide the password to the keystore.