Resource relationships in Managed Service for OpenSearch

OpenSearch is a distributed system for data search and analysis. It uses the document data model, in which a document is a logical counterpart of a row in relational databases. Each document stores key-value pairs, e.g., in JSON format.

Document example:

{
"name": "John Doe",
"gpa": 3.89,
"grad_year": 2022
}

Each document added to OpenSearch goes into an index. After indexing, document data will be available for search and analysis.

OpenSearch features OpenSearch Dashboards, a data visualization UI.

The main entity Managed Service for OpenSearch operates is an cluster.

Each cluster consists of one or more hosts, which are virtual machines with deployed OpenSearch. Cluster hosts may reside in different availability zones. The minimum number of hosts in a cluster depends on the selected cluster configuration and high availability requirements.

When creating a cluster, specify:

• Host classes: VM templates for deploying the cluster hosts.

• Host groups: Groups of multiple linked hosts with specific configuration and roles:

  • DATA: Enable index storage and request processing.
  • MANAGER: Ensure fault tolerance of all OpenSearch components.
  • DASHBOARDS: Provide access to OpenSearch Dashboards.

• Environment where the cluster will be deployed:

  • PRODUCTION: For stable versions of your applications.
  • PRESTABLE: For testing purposes. The prestable environment is similar to the production environment and likewise covered by an SLA, but it is the first to get new features, improvements, and bug fixes. In the prestable environment, you can test new versions for compatibility with your application.

An OpenSearch cluster created in a folder can be accessed by all VMs connected to the same cloud network as the cluster.

Be mindful of what is managed by the service and what, by the Yandex Cloud customer. Understanding these areas of management helps you use your cloud resources efficiently and avoid potential database-related issues. For more information, see Zones of control between managed database (MDB) service users and Yandex Cloud.

High availability of a clusterHigh availability of a cluster

For a cluster to be highly available and covered by a service level agreement (SLA), the following conditions must be met:

1. The cluster must have two or more hosts with the DATA role.
2. The cluster must have three or more hosts with the MANAGER role.

More on high-availability of clusters.