Clusters Overview

    Clusters are managed deployments of Couchbase Server.

    This page walks you through an overview of clusters in Couchbase Capella. A cluster is a managed deployment of Couchbase Server. A cluster comprises one or more instances of Couchbase Server, each running on an independent node.

    In the Capella hierarchy, projects are contained in organizations. Clusters are contained in projects. Clusters are fully managed and deployed in Couchbase’s VPC for a chosen cloud provider.

    If you are using Couchbase Server 6.6 deployed to your own cloud account, the Capella hierarchy is the same. However, clusters are deployed on your connected cloud.


    A cluster comprises one or more services. Couchbase services enable you to access and maintain your data.

    The following services are available:

    Service Description Further Information

    Data Service

    Supports the storing, setting, and retrieving of data items specified by key.

    All clusters must run the Data Service. The Data Service must run on at least one node of every cluster. However, at least three nodes are required for production environments. Clusters with fewer than three Data nodes have several limitations.

    Data Service

    Query Service

    Parses queries specified in the N1QL query language, executes the queries, and returns results. The Query Service interacts with the Data and Index Services.

    Query Service

    Index Service

    Creates indexes used by the Query Service.

    Index Service

    Search Service

    Create indexes specially purposed for Full Text Search. This service supports language-aware searching. For example, it can allow users to search for beauties and obtain results for beauty and beautiful.

    Search Service

    Analytics Service

    Supports join, set, aggregation, and grouping operations, which are expected to be large, long-running, and highly consumptive of memory and CPU resources.

    Analytics Service

    Eventing Service

    Supports near real-time handling of data changes. Code can be executed in response to document mutations and as scheduled by timers.

    Eventing Service

    Deploying Services

    Each instance of a service runs on its own service group. A service group includes the Couchbase services that are deployed on a cluster node, and the system resources, such as compute and storage, of the cloud VM that the node is deployed with. Each service group also has a node quantity. Node quantity represents the number of nodes in the cluster with the same configuration.

    Each service can be deployed, maintained, and provisioned independently of one another. This is known as Multi-Dimensional Scaling.

    You can perform the following actions:

    Action Example

    Deploy different services with different virtual machine types.

    Deploy the Data Service on VMs that have a large amount of memory. Deploy the Index Service on VMs that have a very high storage I/O rating.

    Scale a service up or down by adding or removing virtual machines.

    Add another VM to increase capacity when resource capacity is running low for one of the services.

    Scale a service up or down by changing the virtual machine type of an existing VM.

    Change the VM type to one with lower capacity when a service has a lot of excess resource capacity.

    Couchbase Versions

    New and upgraded clusters are deployed with the latest patch version of Couchbase Server available on Couchbase Capella for the minor version deployed. Version upgrades are scheduled when they become available. You can reschedule maintenance upgrades.

    For more information about upgrades, see Upgrading a Cluster.

    See Also

    See the following pages for more information about managing clusters: