Hyper-Converged Database (HCD) compatibility with Apache Cassandra®
Hyper-Converged Database (HCD) is based on Apache Cassandra®, a distributed NoSQL database. Therefore, each HCD version has an underlying Cassandra base version upon which HCD enhancements are built.
Whether you are planning an upgrade, migration, or new deployment, it is important to understand the compatibility between HCD, the underlying Cassandra version, and related components, such as the Cassandra Query Language (CQL) version and SSTable formats and versions. Additionally, you need a supported operating system and Java version, as well as compatible versions of any additional software you might need.
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If you are migrating to HCD from OSS Cassandra or another Cassandra-based database, understanding compatibility between Cassandra and HCD versions, particularly SSTable formats and versions, is crucial for a successful migration. You might need to prepare your data before migrating to HCD, for example, by altering schemas or upgrading SSTables. |
To assist with upgrades from earlier versions, this guide includes information for multiple versions of HCD.
Supported platforms for HCD
For optimal performance in Linux environments, DataStax recommends using the latest version of a compatible Linux distribution. Newer versions of Linux handle highly concurrent workloads more efficiently. Some examples of compatible Linux distributions include Amazon Linux, Oracle Linux, Red Hat Enterprise Linux (RHEL), and Ubuntu.
For more information about platform compatibility and system requirements, see the following:
Cassandra specifications and compatibility for HCD
These tables provide the following information:
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HCD version: The relevant HCD version. A range of patch releases is given if applicable. Otherwise, the stated version implies all associated patch releases.
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Cassandra version: The underlying Cassandra base version. Support for production-certified enhancements refers to enhancements for the specified Cassandra version.
You can use the base version as a reference point when considering Cassandra-compatible software or tools, if HCD isn’t explicitly mentioned.
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CQL version: The CQL version associated with the underlying Cassandra base version. This informs the CQL statements, data types, and other functionality that you can use to interact with your databases. Enhancements aren’t always supported.
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SSTable format and version: The SSTable format and version used for new SSTables and SSTables that are loaded or upgraded with
nodetool upgradesstables,sstableloader, andsstableupgrade. -
SSTable support in
sstableloader: SSTable formats and versions that can be read and processed by thesstableloadertool. If an SSTable isn’t in one of these formats, you must upgrade it to a supported format before usingsstableloader. -
SSTable support in
sstableupgradeandnodetool upgradesstables: SSTable formats and versions that can be read and processed by thesstableupgradetool or thenodetool upgradesstablescommand. If an SSTable isn’t in one of these formats, you must upgrade it to a supported format before using these tools in the specified HCD version.
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Verify SSTable format and version compatibility when using |
| HCD version | Cassandra version | CQL version | SSTable format and version | SSTable support in sstableloader |
SSTable support in sstableupgrade and nodetool upgradesstables |
|---|---|---|---|---|---|
1.2.0 |
Compatible with 3.11 and production-certified enhancements |
3.4.5 |
bti-bb |
big-ma, big-mb, big-mc, big-md, bti-aa, bti-ac, bti-b, bti-bb |
big-ma, big-mb, big-mc, big-md, bti-aa, bti-a |
1.1.0 |
Compatible with 3.11 and production-certified enhancements |
3.4.5 |
bti-bb |
big-ma, big-mb, big-mc, big-md, bti-aa, bti-ac, bti-b, bti-bb |
big-ma, big-mb, big-mc, big-md, bti-aa, bti-a |
CQL and SSTable specifications for OSS Apache Cassandra
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Verify SSTable format and version compatibility when using |
When migrating data into HCD from Apache Cassandra, such as with sstableloader, verify that the incoming SSTable format and version is compatible with your HCD version.
The following table describes CQL and SSTable versions for OSS Cassandra 3.11 and earlier. For later Cassandra versions, see the OSS Cassandra documentation and other resources.
Once you know your current SSTable format and version, compare that version to the compatible formats and versions for your HCD version.
| Cassandra version | CQL version | SSTable format and version |
|---|---|---|
3.11.11 and later |
3.4 |
big-me |
3.11.4 to 3.11.10 |
3.4 |
big-md |
3.9 to 3.11.3 |
3.4 |
big-mc |
3.7 to 3.8 |
3.4 |
big-mb |
3.1 to 3.6 |
3.4 |
big-ma |
3.0.18 and later |
3.4 |
big-md |
3.0.8 to 3.0.17 |
3.4 |
big-mc |
3.0.7 |
3.4 |
big-mb |
3.0.3 to 3.0.6 |
3.4 |
big-ma |
3.0.0 to 3.02 |
3.3 |
big-ma |
2.2.7 and later |
3.3 |
big-lb |
2.2.0 to 2.2.6 |
3.3 |
big-la |
2.1 |
3.1 |
big-ka |
bti and big SSTable formats
Because HCD is based on Apache Cassandra, it inherits the SSTable format conventions from the underlying Cassandra version, among other base features and functionality.
By design, each HCD version includes enhancements that extend the underlying Cassandra version.
Some DataStax enhancements diverge significantly from the underlying Cassandra version, such as the use of the bti SSTable format in HCD.
HCD uses the bti SSTable format.
However, OSS Cassandra didn’t support the bti format until Cassandra 5.0.
Earlier versions of Cassandra, including Cassandra 3.x, use the big SSTable format, with the exception of very early versions that predate named SSTable formats.
You can load and upgrade both big and bti SSTables in HCD.
For specific SSTable formats and versions that are supported by sstableloader, sstableupgrade, and nodetool upgradesstables in HCD, see Cassandra specifications and compatibility for HCD.
If you are loading or upgrading SSTables from OSS Apache Cassandra, see CQL and SSTable specifications for OSS Apache Cassandra.
HCD compatibility with other tools and software
Make sure all tools you use with HCD are compatible with your operating system and HCD version (or the underlying Cassandra version). For example:
Migrations from DSE
If you are migrating from DataStax Enterprise (DSE), see Cassandra and SSTable compatibility for DSE.
