Cassandra - Capabilities and Limitations

This page provides the technical capabilities and limitations of the Managed Databases (also called Cloud Databases) Cassandra offer.

We continuously improve our offers. You can follow and submit ideas to add to our roadmap.

Capabilities and limitations

Supported regions

To view Cloud Databases availability, please see our regions and availability webpage.

Entire database instances have to be in the same region.

Cassandra versions

The Cloud Databases offer supports the following Cassandra versions:

• Cassandra 4.1

Cassandra recommends always installing and using the latest stable version.

Plans

Three plans are available:

• Essential
• Business
• Enterprise

Here is an overview of the various plans' capabilities:

Your choice of plan affects the number of nodes your cluster can run, the SLA, and a few other features such as read replicas or backup retention.

Nodes and replicas

• Essential: The cluster is delivered with 3 nodes by default.
• Business: The cluster is delivered with 3 nodes by default. Adding read replicas is planned.
• Enterprise: The cluster is delivered with 6 nodes by default. Adding read replicas is planned.

License type

Each cluster is provided with the Cassandra Community (GPL) license.

If any, license cost is included in the service plans. You can't bring your own licenses.

Hardware resources

For detailed information about node types and pricing, please refer to the Public Cloud pricing page.

Flexible storage

You can increase your cluster's storage up to the maximum allowed for a given reference. Please refer to our Cloud Databases - Resize Your Cluster Storage guide for more information.

Node template upgrade

You can upgrade the node template of your cluster to scale your hardware resources up. This operation causes no interruption of service but be aware that you will not be able to downgrade the node template afterwards.

Disk type

The type of storage available may vary according to the region your cluster lives in: see Availability of Public Cloud products for more information about block storage type availability depending on the region. Thus, your cluster may be backed by e.g. High Speed or High Speed Gen2 block storage.

Also, the performance characteristics of the various storage offerings may vary depending on e.g. the storage size your cluster uses: High Speed may offer better IOPS than High Speed Gen2 for some disk sizes. See our Block Storage webpage for more information about those performance characteristics.

Cloud Databases will select your cluster's most efficient disk type depending on your cluster parameters.

Effective storage

The disk size listed above is the total disk size of the underlying machine. However, a small part of it goes towards the OS install.

We try hard to avoid "disk full" situations that could be harmful to cluster health. Therefore:

1. When reaching a concerning level of disk usage, a warning email is sent.
2. When reaching a concerning level of disk usage, the service is moved to the "DISK_FULL" state, and "read-only" mode, meaning no more writes can be done.

See our Cloud Databases - Handling «Disk Full» Situations guide for more information.

Features

Network

Public as well as private networking (vRack) can be used for all the offers.

Ingress and Egress traffic are included in the service plans and unmetered.

The database service's IP address is subject to change periodically. Thus, it is advised not to rely on these IPs for any configuration, such as connection or egress policy. Instead, utilize the provided DNS record and implement CIDR-based egress policies for more robust and flexible network management.

Private network considerations

Here are some considerations to take into account when using a private network:

• Network ports are created in the private network of your choice. Thus, further operations on that network might be restricted - e.g. you won’t be able to delete the network if you didn’t stop the Public Cloud Databases services first.
• When connecting from an outside subnet, the OpenStack IP gateway must be enabled in the subnet used for the Database service. The customer is responsible for any other custom network setup.
• Subnet sizing should include considerations for service nodes, other co-located services within the same subnet, and an allocation of additional available IP addresses for maintenance purposes. Failure to adequately size subnets could result in operational challenges and the malfunctioning of services.
• OpenStack subnets routes announcement will not be applied to your services.
• You can only create private network services if you are the original owner of the network. You cannot create private network services on a shared network.

Authorized IPs

Once your service is up and running, you will be able to specify IP addresses (or CIDR blocks) to authorize incoming traffic. Until then, your service will be unreachable.

Advanced parameters

You can further customize your Cassandra by using advanced parameters. See our Cassandra - Advanced Parameters References for more information on the supported parameters.

Backups

Your services are automatically backed up daily. Backup retention is 4 days for daily backups.

See our Cloud Databases - Automated Backups guide for more information.

Logs and metrics

Logs and metrics are available through the Control Panel and the API and can be forwarded to Logs Data Platform. Additionally, cross-service integration can be configured to leverage your logs and metrics in other Public Cloud Database services. You could then view your Cassandra logs in OpenSearch and metrics in Grafana (metrics have to be exported first in a time series compatible engine such as PostgreSQL). See our Cloud Databases - Cross Service Integration guide for more information.

• Logs retention: 1000 lines of logs
• Metrics retention: 1 calendar month

Please note that if the database instance is deleted, logs and metrics are also automatically deleted.

Go further

For more information and tutorials, please see our other Managed Databases & Analytics or Platform as a Service guides. You can also explore the guides for other OVHcloud products and services.