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Connecting a GridGain Cluster

This page explains how to connect a GridGain cluster to Nebula. You can connect as many clusters as you want. GrudGain Nebula allows you to switch between clusters at will.

A standard procedure for connecting a GridGain cluster to Nebula involves the following steps:

  1. Configure your cluster

    1. Enable the Control Center Agent module

    2. Enable metrics

    3. Optionally, enable tracing

  2. Register the cluster in Nebula.

The following diagram illustrates how Nebula interacts with the cluster and the web browser.

Connect GridGain Cluster to Nebula

Configuring Your Cluster

Enabling the Control Center Module

The connection between the cluster and Nebula is initiated from the cluster side.

For this to happen, you need to enable the control-center-agent module in the cluster. The module must be enabled on all server nodes. If you plan to connect client nodes to your cluster, enable the module on the client nodes as well. Otherwise, you will get the following exception on the client node:

java.lang.ClassNotFoundException: org.gridgain.control.agent.configuration.ControlCenterAgentConfiguration

Depending on how you deploy your cluster, you can enable the module in different ways:

  • If you start nodes from the distribution package by executing, copy the {GRIDGAIN_HOME}/libs/optional/control-center-agent folder to {GRIDGAIN_HOME}/libs/.

  • If you start nodes using Maven, see this section for the information on how to enable modules.

  • If you use a GridGain Docker image, see Enabling Modules.

When you start your cluster with the Control Center Agent enabled, you can use the script to enable and disable management capabilities. The management script is located in the bin directory of the distribution package and you. Detailed descriptions are available in the Command Line Options page.

As the cluster tries to connect to Nebula, you should see the following messages in the console output of the coordinator node (the oldest node in the cluster):

node output

You can copy the link and open it in your browser, or you can copy the token and add the cluster in Nebula.

Enabling Metrics

Nebula collects metrics from the clusters that are running. Most metrics are available by default, but some metrics must be enabled in the cluster before you can view them in Nebula.

You can enable metrics in two ways:

  • In the cluster configuration, or

  • Via JMX Beans at runtime

Refer to this page for details.

Enabling Tracing

You can enable tracing capabilities and view traces in Nebula in two ways:

  1. The best way to configure tracing is to use the Tracing screen of the Nebula.

  2. To configure tracing programmatically, see the Tracing page for more detail.

Assigning Cluster Name

You can assign a user-friendly name to your cluster. The name is displayed in Nebula. Use the following command to assign a name:

{IGNITE_HOME}/bin/ --change-tag newTagValue [--yes]

If you don’t set the cluster name, the auto-generated cluster name is displayed instead.