Scylla on Compose

Scylla is a lightning fast, low-latency, NoSQL clustered database that boasts 1 million transactions per second per node. As a drop-in replacement for Cassandra, Scylla is ready to run your app with blazingly fast reads and writes.

Scylla for All is a general introduction to Scylla on Compose.

Are you wondering what you'll get, or can get, with a Compose Scylla deployment? Want to know what you'll need to do to manage it? Check out some of the implementation features and details down in Scylla for Ops and Admins.

Just deployed Scylla and want to get coding with it? Developing an application or want to try a new stack? Then see the
Scylla for Developers section for resources on how to connect from different languages, command line tools and more information to get you started.

Scylla for All

When deployed on Compose, Scylla comes with these standard Compose features.

Compose deployments of Scylla also come with a number of Scylla specific features:

  • Data Browser For Scylla.
  • An optional add-on for real-time log access.
  • Drop-in replacement for Cassandra 2.1.8, supporting the tool chain, drivers, and built in query language, cql.
  • Start with 5GB storage for $103.50 - as you grow each additional gigabyte costs $18.

Compose Configuration

Scylla requires fast IO and as much RAM as the total data size. For Scylla to do its thing, it needs a good chunk of memory so we start your deployment off with 1GB RAM and 10GBs storage across 3 member nodes on an SSD backed cluster. Access is provided through three haproxy capsules that have 64MB each and support authentication, HTTPS, and IP whitelisting for enhanced security.

Expansion Options

For standard deployments, automatic vertical scaling occurs as your data set grows. You can also manually scale up your haproxy portals and Scylla deployment from the deployment's Resources panel. A 10:1 ratio of disk to RAM is maintained, so by increasing the disk allocated to the deployment, you increase the RAM allocated. Additional resources are available in 5GB storage/510 MB memory chunks.

It is also possible to add additional TCP/haproxy portals from the Security panel.

For more information see the Scylla Resources and Scaling page.

Datacenter Availability

See Compose Datacenter Availability for current location availability.

Billing and Costs

Compose deployments are billed on hourly basis and grouped into a single monthly billing cycle. This means that any scaling or add-on usage will be charged from when the new resource was provisioned; not just for the month.

Depending on which scaling and add-ons options you choose, the cost will increase. For example, if you wish to add extra storage and RAM, it is billed at an additional $18/month per unit of 1GB storage/102MB memory, so an additional 5GB storage/510MB memory will cost an additional $90/month.

General billing information, answers, and details can be found in the Billing FAQ page.

For Ops and Admins

High Availability and Failover

Scylla stores replicas on multiple nodes to ensure reliability and fault tolerance. All replicas are equally important; there is no primary or master replica, and each node knows about the other nodes. The total number of replicas across the cluster is referred to as the replication factor. A replication factor of 1 means that there is only one copy of each row on one node. A replication factor of 3 means three copies of each row, where each copy is on a different node, which is the standard configuration that Compose Scylla deployment offers.

The three haproxy servers load-balance requests and provide failover stability as well as authentication, HTTPS, and IP whitelisting for additional security.


Scylla backups are taken using the nodetool snapshot utility, backing up all the on-disk data files stored in the data directory. The snapshot can run while your databases are on-line. Incremental backups are not enabled on Compose deployments (which is also the default for Scylla), so any one backup can be used to make a full restore of your deployment.

Should something happen to your current deployment; Scylla backups can be restored directly into a new Scylla deployment. The Backups panel has all the available daily, weekly, monthly, or on-demand backups for you to restore from. It is also possible to trigger a restore operation from the Compose API.

For more details see the Backups page and the Managing Backups via the Compose API page.

For Developers

CLI Tools

The two tools that are used to communicate with and administrate Scylla are the CQL shell, cqlsh and nodetool. There are installation and usage instructions over on the Scylla and cqlsh and Scylla and nodetool pages.

Connecting to Scylla

The Overview panel of the Compose UI provides the basic information you need to get connected to your databases. In the section Connection info you will find Credentials and Connection Strings for your application. Cqlsh Command Line strings for connecting from your local machine or development environment. For specific connection information and examples, see the Connecting to Scylla page for details.

This section also has the Address Translation Map for your deployment for drivers that support this type of connection. Usage information is on the Address Translation Maps page.

Additional Resources and Related Articles

The full list of documentation for Scylla is in the sidebar, in addition to all things Compose.

For more than just help docs, check out Compose Articles and our curated collection of Scylla-related topics for more how-to's and information on Scylla on Compose.

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