The X-Pack monitoring features let you monitor Elasticsearch through Kibana. You can view your cluster’s health and performance in real time and analyze past cluster, index, and node metrics. In Elasticsearch versions before 5.0, Marvel provides similar monitoring functionality.
In Elasticsearch 5.0 and later, the monitoring features of Marvel became part of X-Pack. If you are using an Elasticsearch version before 5.0, think Marvel whenever you read about the X-Pack monitoring features.
Monitoring consists of two components:
- A Monitoring agent that is installed on each node in your cluster. The Monitoring agent collects and indexes metrics from Elasticsearch, either on the same cluster or by sending metrics to an external monitoring cluster. Elastic Cloud manages the installation and configuration of the monitoring agent for you, and you should not modify any of the settings.
- The Monitoring (formerly Marvel) application plugin in Kibana that visualizes the monitoring metrics through a dashboard.
The steps in this section cover only the enablement of the monitoring features. For more information on how to use the monitoring features, see the X-Pack Monitoring documentation for version 5.0 and later or the Marvel documentation for versions before 5.0.
For production use, you should log metrics for clusters to a dedicated monitoring cluster. Monitoring indexes metrics into Elasticsearch and these indexes consume storage, memory and CPU cycles like any other index. By using a separate monitoring cluster, you avoid affecting your production clusters.
You should also create a dedicated user for the clusters sending metrics and the monitoring cluster receiving them. For more information on creating a user with the right privileges, see Monitoring and Security (for version 5.0 and later) and Using Marvel with Shield (for versions before 5.0).
How many monitoring clusters you use depends on your requirements:
- You can ship metrics for many clusters to a single monitoring cluster if your business requirements permit it.
- While monitoring will work with a cluster running a single node, you need a minimum of three monitoring nodes to make monitoring highly available.
You might need to create dedicated monitoring clusters for isolation purposes in some cases. For example:
- If you have many clusters and some of them are much larger than others, creating separate monitoring clusters prevents a large cluster from potentially affecting monitoring performance for smaller clusters.
- If you need to silo Elasticsearch data for different business departments. Clusters that have been configured to ship metrics to a target monitoring cluster have access to indexing data and can manage monitoring index templates, which is addressed by creating separate monitoring clusters.
Monitoring data that gets sent to a dedicated monitoring cluster is not cleaned up automatically and might require some additional steps to remove periodically.
To avoid compatibility issues between versions, the cluster sending monitoring metrics and the monitoring cluster receiving them should be at the same Elasticsearch version. If using the same version is not feasible, check for breaking changes in the X-Pack Release Notes or the Marvel Release Notes to make sure that your versions are compatible.
When you enable monitoring on Elastic Cloud by configuring your cluster to send monitoring data to itself, your monitoring indices are retained for a certain period by default. After the retention period has passed, the monitoring indices are deleted automatically. The retention period when a cluster sends monitoring data to itself depends on the version of Elasticsearch:
For Elasticsearch 5.x clusters: Monitoring data is retained for three days by default or as specified by the
- For Elasticsearch 2.x clusters: Monitoring data is retained for seven days.
When monitoring for production use, where you configure your clusters to send monitoring data to a dedicated monitoring cluster for indexing, this retention period does not apply. Monitoring indices on a dedicated monitoring cluster are retained until you remove them. There are two options open to you:
- To enable the automatic deletion of monitoring indices from dedicated monitoring clusters, enable monitoring on your dedicated monitoring cluster on Elastic Cloud to send monitoring data to itself. When a cluster on Elastic Cloud sends monitoring data to itself, all monitoring indices are deleted automatically after the retention period, regardless of the origin of the monitoring data.
- To retain monitoring indices on a dedicated monitoring cluster as is without deleting them automatically, no additional steps are required other than making sure that you do not enable the monitoring cluster to send monitoring data to itself. You should also monitor the cluster for disk space usage and upgrade your cluster periodically, if necessary.
Elastic Cloud manages the installation and configuration of the Monitoring agent (formerly Marvel) for you. When you enable Monitoring on a cluster, you are configuring where the monitoring agent for your current cluster should send its metrics.
To enable the Monitoring agent:
- Sign in to the Elastic Cloud Console.
- Go to the Configuration page for your cluster.
Under Monitoring, select a target cluster and click Update.
If a cluster is not listed, make sure that it is running a compatible version and is configured to use the Elastic Stack security features (X-Pack for Elasticsearch 5.0 and later or Shield for versions before 5.0).
Remember to send metrics for production clusters to a dedicated monitoring cluster, so that your production clusters are not impacted by the overhead of indexing and storing monitoring data. A dedicated monitoring cluster also gives you more control over the retention period for monitoring data.
With monitoring enabled for your cluster, you can access the Monitoring (formerly Marvel) application through Kibana. The application is a plugin that runs in Kibana.
To access the Monitoring application:
Open Kibana on the cluster that is receiving monitoring metrics.
For example, if you have a monitoring and a production cluster, and the production cluster is shipping metrics to the monitoring cluster, then you need to open the Monitoring application on the monitoring cluster to see the metrics.
If you are not sure where to access Kibana on the cluster, log into the Cloud UI on the cluster that is receiving the metrics, and look up the Kibana endpoint URL.
In Kibana, open the Monitoring application:
- In Kibana 5, click on Monitoring in the sidebar on the left.
In Kibana 4.5, first click on the App Switcher icon and then click on the Marvel app icon.
After you open the application in Kibana, you see a list of the clusters that you are monitoring.
Start exploring monitoring data:
Detailed monitoring information is available through the X-Pack monitoring features (called Marvel in versions before 5.0), but some monitoring information reports only host-level statistics and not containers statistics. Because your cluster nodes run within containers on Elastic Cloud, some system metrics do not reflect the utilization for your cluster nodes but rather the utilization of the host that they’re running on. We have begun to make improvements to X-Pack monitoring to show accurate metrics and, starting in version 5.2, the CPU usage and throttle times are accurately captured over time.
For now, the following system metrics in the Monitoring app should not be used to monitor your clusters on Elastic Cloud:
- IP address
- Reports the internal private IP address, which is not usable externally.
- Free disk space
- Reports the total free space on the host, not the storage assigned to your cluster.
- CPU statistics
- For versions before 5.2: Reports CPU utilization for the host, not the container that cluster nodes run in. For version 5.2 and later: Can be used, as CPU utilization accurately reflects the CPU resources assigned to your cluster nodes, based on the reported cgroups statistics. The CPU utilization and throttle information can be found on the Nodes tab and the details view when you click on a node.
- System load average
- Reports the load average for the host, not the container that cluster nodes run in.
For accurate system metrics within the last 24 hours, you can always use the cluster performance metrics available directly from the Overview page for each cluster in the Elastic Cloud Console.