Expanding your Cluster | Cassandra Documentation
This article explains how to permanently expand the capacity of your cluster. We also offer dynamic scaling (https://www.instaclustr.com/support/documentation/cluster-management/in-place-data-centre-resizing/) for more elastic changes in the processing capacity of your cluster.
The processing and storage capacity of a cluster scales linearly as new nodes are added.
In general, you will keep the number of nodes balanced across Cassandra rack configurations when adding nodes. So, if you have three racks in your cluster you will add nodes three at a time.
Adding new nodes to a cluster can be completed without any interruption to service. However, the process of new nodes syncing data with the cluster puts a load on the cluster so we recommend scheduling for a low usage period. The process of a new node joining the cluster may take several hours. The overhead of syncing a new node is particularly apparent in a small cluster (as the new nodes are a more significant portion of the overall cluster capacity).
It is important to add capacity well before existing capacity (particularly disk space) is exhausted. We do not recommend running any node at >70% disk utilisation in normal operations.
Table of Contents
- To add nodes to your existing cluster, log into Instaclustr console.
- Click Add Nodes from the Manage Cluster menu.
- Fill in the required information on the Add Nodes page and click Submit Request button.
Note: To ensure consistent stability and performance, Instaclustr support will verify the health of your cluster before provisioning additional nodes. We aim to complete this process within one business day and will contact you to confirm when these additional nodes have been provisioned.
Adding Data Centre
- To add Data Center to your existing cluster, log into Instaclustr console.
- Click Add Data Center from the Manage Cluster menu.
- On the Add Data Centre page choose a configuration matching your requirements.
- Under Applications section, select any add-ons you require.
- Under Data Centre section, select your Infrastructure Provider, Region, Custom Name (which is a logical name for the data centre within Cassandra), Data Centre Network range, Node Size, EBS Encryption option, Replication Factor and number of nodes. Refer our support article on Network Address Allocation to understand how we divide up the specified network range to determine the node IP addresses.Note: Multi-region or multi-provider clusters will incur additional network charges. Please contact firstname.lastname@example.org to confirm.
- Under Cassandra Options section, select your Network and Security settings. The Summary section displays a brief summary of your datacenter configurations and pricing details. Once all the required information is filled in, click Submit Request button.Note: To ensure consistent stability and performance, Instaclustr support will verify the health of your cluster before provisioning an additional data centre. We aim to complete this process within one business day and will contact you once the additional data centre has been provisioned.