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Databases · head to head

Cassandra vs Seldon

Cassandra logo

Cassandra

Databases

Manage massive amounts of data with linear scalability

From
Free
Free plan
Yes
Visit CassandraFull review
Seldon logo

Seldon

Machine Learning

Kubernetes model serving whose current version is licensed under the Business Source Licence

From
Free
Free plan
Yes
Visit SeldonFull review

The short version

  • Both are free.
  • Only Cassandra lists linear Scalability; only Seldon lists kubernetes custom resources.
  • Where Cassandra falls short: no support for joins across tables.
  • Prices and features on this page were last checked on 13 November 2026.

Where they differ

Only the attributes on which Cassandra and Seldon actually diverge.

Attributes where Cassandra and Seldon differ
AttributeCassandraSeldon
PlatformsLinux, macOS, Windows, Self-hostedLinux
CategoryDatabasesMachine Learning
Founded20082014

Identical on both: starting price (Free), free tier (Yes).

Not yet recorded: pricing model for Cassandra.

What each one covers

Drawn from each product's published feature list. An absence here means we hold no record of it - not that the product lacks it.

Only in Cassandra

  • Linear Scalability
  • Fault Tolerance
  • Multi-datacenter Replication
  • Tunable Consistency
  • CQL Query Language
  • Distributed Architecture
  • No Single Point of Failure
  • DataStax

Only in Seldon

  • Kubernetes custom resources
  • Inference graphs
  • Traffic strategies
  • Open Inference Protocol
  • Alibi Explain
  • Alibi Detect
  • Kafka-backed pipelines in v2
  • Commercial control plane

What people use each for

The jobs each tool is most often brought in to do.

Cassandra

  • Real-time applicationsnot Seldon
  • Content managementnot Seldon
  • User profilesnot Seldon
  • Mobile backendsnot Seldon
  • Cachingnot Seldon

Seldon

  • Serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate servicesnot Cassandra
  • Running genuine production experiments where a share of live traffic goes to a candidate model and the results are comparednot Cassandra
  • Regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on laternot Cassandra
  • Organisations with an established Kubernetes platform team who want serving expressed as manifests under existing deployment controlsnot Cassandra

Where each one falls short

Documented limitations, not opinions. Every one is a constraint you would hit in normal use.

Cassandra

  • No support for joins across tables
  • No ACID transactions across multiple rows
  • Data model must be designed around query patterns upfront, making schema evolution difficult
  • Partition key misconfigurations can cause uneven data distribution and hotspots that degrade performance

Seldon

  • Seldon Core v2 is under the Business Source Licence rather than Apache 2.0, so production use requires a commercial agreement, and a team that evaluated it believing it was open source discovers the licence is the blocker exactly when the project is ready to ship
  • Core v1 remains Apache 2.0 but is in maintenance, so taking the free route means running software that receives no new development while the architecture it belongs to moves on without it
  • Version 2 is a different system rather than a newer release, with different custom resources, a scheduler component and a Kafka-based pipeline model, so migrating from v1 is a re-implementation of every deployment manifest rather than an upgrade
  • Kafka is a dependency for v2 pipelines, so an organisation that does not already operate it takes on a distributed log with its own storage, retention, rebalancing and failure modes purely in order to serve models
  • Everything assumes Kubernetes fluency and the failure modes are Kubernetes failure modes, custom resource version mismatches, an operator that will not reconcile, admission webhooks and resource limits terminating an inference pod mid-request, so it needs a platform engineer rather than a data scientist

Pricing, plan by plan

Cassandra

Free

No published plan breakdown. See the Cassandra review.

Seldon

Free
  • Seldon CoreFree
    • Open source
    • Kubernetes deployment
    • Model serving
  • Seldon DeployFree
    • Enterprise features
    • GUI
    • Monitoring

Which should you pick?

Choose Cassandra if

  • You need linear scalability.
  • You want to start without paying.
  • You work on Linux, macOS, Windows, Self-hosted.
  • You also want fault tolerance.
Cassandra review

Choose Seldon if

  • You need kubernetes custom resources.
  • You want to start without paying.
  • You work on Linux.
  • You also want inference graphs.
Seldon review

Questions people ask

Is Cassandra or Seldon better?
Neither clearly leads. Cassandra starts at Free and Seldon at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Cassandra or Seldon?
Cassandra starts at Free and Seldon at Free.
Does Cassandra or Seldon run on more platforms?
Cassandra runs on Linux, macOS, Windows, Self-hosted. Seldon runs on Linux.
Can I use Cassandra for free?
Both have a free tier, so you can try either at no cost before committing.
What is Cassandra best used for?
Cassandra is most often used for real-time applications, content management, user profiles, mobile backends. Of those, real-time applications and content management are not what Seldon is typically brought in for.
What can Cassandra do that Seldon cannot?
Cassandra covers Linear Scalability, Fault Tolerance, Multi-datacenter Replication, Tunable Consistency. Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol.

Answered from the vendors’ own pages

Cassandra: Does Cassandra support joins between tables?

No. Cassandra does not support joins or foreign keys. The data model requires denormalization, meaning data must be duplicated across tables to support different query patterns.

Source
Seldon: Is Seldon open source?

Partly, and this is the thing to check before you build on it. Core v1 is Apache 2.0 but in maintenance. Core v2 was moved to the Business Source Licence in 2024, which allows evaluation but not unlicensed production use. Verify the current licence of each component you intend to run, including MLServer and the Alibi libraries.

Cassandra: Does Cassandra offer ACID transactions?

No. Cassandra provides only row-level atomicity and isolation, not full ACID transactions across multiple rows or tables. It uses lightweight transactions via Paxos for per-row compare-and-set operations.

Source
Seldon: What is the difference between v1 and v2?

Architecture, not just version number. v2 introduces a scheduler, a different set of custom resources and Kafka-backed pipelines. Manifests, mental model and operations all change, so treat a move as a project.

Cassandra: What programming languages can connect to Cassandra?

Cassandra supports official drivers for multiple languages including Python, Java, Node.js, and Go, allowing applications to communicate via the native Cassandra protocol.

Source
Seldon: Do I need Kubernetes?

Yes. It is a Kubernetes-native system and there is no meaningful deployment without a cluster and someone competent to run it.

Cassandra: Can I deploy Cassandra in the cloud?

Yes. Cassandra can run on any cloud platform (AWS, Google Cloud, Azure) via Docker, virtual machines, or managed services like DataStax Astra DB, which provides a fully managed DBaaS option.

Source
Seldon: What is MLServer?

Seldon's Python inference server implementing the Open Inference Protocol, usable inside Seldon deployments or on its own. Check its current licence alongside Core's, since the company has moved projects onto the Business Source Licence.

Cassandra: Does Cassandra have a free option?

The open source Apache Cassandra is free. DataStax also offers Astra DB with a free tier providing up to 25GB storage and 25 million read/write operations per month.

Source
Seldon: Do I have to run Kafka?

For v2 pipelines, yes. If you only need single models served, that dependency is a large amount of infrastructure for the benefit, and a simpler serving layer may be the better answer.

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