OpenSearch Node Groups
An OpenSearch cloud database cluster consists of groups of nodes into which nodes are organized based on their role:
Node group with the Manager role
A group of nodes with the Manager role responds:
- for managing the state of the cluster;
- data and task allocation;
- fault tolerance;
- load balancing;
- processing of control operations;
- master node selection;
- Monitoring and collecting metrics.
This is a mandatory node group that includes three nodes. This node group cannot be changed or deleted.
Group of nodes with the Data role
A node group with the Data role is a cluster component that performs tasks related to indexing, sharding, replication, and query processing. For example, a node group with the Data role is responsible for:
- for data storage;
- processing requests;
- data replication;
- load balancing;
- providing fault tolerance;
- index optimization;
- horizontal zoom support;
- interaction with master nodes.
OpenSearch cluster must have one node group with the Data role. Optionally, you can add one more node group. From one to 10 nodes can be added to each node group.
To avoid overloading and performance degradation, we recommend monitoring CPU, RAM and disk space usage.
Group of nodes with the Dashboard role
The group of nodes with the Dashboard role contains a data visualization tool — OpenSearch Dashboards. Nodes in this group are optimized for processing user requests and performing tasks related to analytics and visualization. The group of nodes with the Dashboard role is responsible for:
- for data visualization;
- processing requests;
- dashboard management;
- visualization of cluster state monitoring;
- analytical query processing;
- working with backups;
- user management and access definition.
This is an optional node group that includes only one node.
Dashboards are not involved in data processing or sharding management, so a group of nodes with the Dashboard role can be separated from the main load on the cluster — for example, you can configure the Dashboard yourself and connect it to the OpenSearch cluster.