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Clusters

Overview

Clusters are pools of compute resources (CPU, memory, and scratch disk space) for running your workloads.

The following operations require compute resources in Materialize, and so need to be associated with a cluster:

Resource isolation

Clusters provide resource isolation. Each cluster provisions dedicated compute resources and can fail independently from other clusters.

Workloads on different clusters are strictly isolated from one another. That is, a given workload has access only to the CPU, memory, and scratch disk of the cluster that it is running on. All workloads on a given cluster compete for access to that cluster’s compute resources.

Best practices

  • Use clusters to isolate different classes of workloads. For example, you could place your development workloads in a cluster named dev and your production workloads in a cluster named prod.

  • Use different clusters to separate sources from sinks. That is, avoid placing sources and sinks in the same cluster.

Fault tolerance

The replication factor of a cluster determines the number of replicas provisioned for the cluster. Each replica of the cluster provisions a new pool of compute resources to perform exactly the same work on exactly the same data.

Provisioning more than one replica for a cluster improves fault tolerance. Clusters with multiple replicas can tolerate failures of the underlying hardware that cause a replica to become unreachable. As long as one replica of the cluster remains available, the cluster can continue to maintain dataflows and serve queries.

NOTE:

  • Each replica incurs cost, calculated as cluster size * replication factor per second. See Usage & billing for more details.

  • Increasing the replication factor does not increase the cluster’s work capacity. Replicas are exact copies of one another: each replica must do exactly the same work as all the other replicas of the cluster(i.e., maintain the same dataflows and process the same queries).

    To increase the capacity of a cluster, you must increase its size.

Materialize automatically assigns names to replicas (e.g., r1, r2). You can view information about individual replicas in the Materialize console and the system catalog.

Availability guarantees

When provisioning replicas,

  • For clusters sized under 3200cc, Materialize guarantees that all provisioned replicas in a cluster are spread across the underlying cloud provider’s availability zones.

  • For clusters sized at 3200cc and above, even distribution of replicas across availability zones cannot be guaranteed.

Cluster sizing

When creating a cluster, you must choose its size (e.g., 25cc, 50cc, 100cc), which determines its resource allocation (CPU, memory, and scratch disk space) and cost. The appropriate size for a cluster depends on the resource requirements of your workload. Larger clusters have more compute resources available and can therefore process data faster and handle larger data volumes.

As your workload changes, you can resize a cluster. Depending on the type of objects in the cluster, this operation might incur downtime. See Resizing downtime for more details.

💡 Tip: To gauge the performance and utilization of your clusters, use the Environment Overview page in the Materialize Console.
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