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Machine Learning · head to head

Seldon vs Vitess

Seldon logo

Seldon

Machine Learning

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

From
Free
Rated
-
Vitess logo

Vitess

Databases

Scalable database clustering system for horizontal scaling of MySQL

From
Free
Rated
-

The short version

  • Each has a real cost: 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.; Vitess vTGate scatter queries without sharding key incur significant performance penalties
  • They diverge on capability: Seldon covers Kubernetes custom resources, Vitess covers Horizontal Sharding.
  • Prices and features above were last checked on 30 August 2026.

Where they differ

Only the attributes on which Seldon and Vitess actually diverge.

Attributes where Seldon and Vitess differ
AttributeSeldonVitess
Pricing modelfreemiumUnknown
PlatformsLinuxLinux, macOS, Docker, Kubernetes
CategoryMachine LearningDatabases
Founded20142010

Identical on both: starting price (Free), free tier (Yes), user rating (Not yet rated).

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 Seldon

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

Only in Vitess

  • Horizontal Sharding
  • Connection Pooling
  • Query Routing
  • Online Schema Changes
  • Shard Management
  • Replication Management
  • Automated Failover
  • MySQL

What people use each for

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

Seldon

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

Vitess

  • Transaction processingnot Seldon
  • Data storagenot Seldon
  • Application backendnot Seldon
  • Reportingnot Seldon
  • Data analyticsnot Seldon

Where each one falls short

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

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.

Vitess

  • VTGate scatter queries without sharding key incur significant performance penalties
  • Foreign key constraints not enforced across shards, requiring application-level integrity handling
  • Single primary per keyspace limits multi-region write capabilities
  • Distributed transactions without proper sharding key routing suffer performance degradation

Pricing, plan by plan

Seldon

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

Vitess

Free

No published plan breakdown. See the Vitess review.

Which should you pick?

Choose Seldon if

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

Choose Vitess if

  • You need horizontal sharding.
  • You want to start without paying.
  • You work on Linux, macOS, Docker, Kubernetes.
  • You also want connection pooling.

Questions people ask

Is Seldon or Vitess better?
Neither clearly leads. Seldon starts at Free and Vitess at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, Seldon or Vitess?
Seldon starts at Free and Vitess at Free.
Does Seldon or Vitess run on more platforms?
Seldon runs on Linux. Vitess runs on Linux, macOS, Docker, Kubernetes.
Can I use Seldon for free?
Both have a free tier, so you can try either at no cost before committing.
What is Seldon best used for?
Seldon is most often used for serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate services, running genuine production experiments where a share of live traffic goes to a candidate model and the results are compared, regulated environments needing explanations and drift monitoring attached to the served model rather than bolted on later, organisations with an established kubernetes platform team who want serving expressed as manifests under existing deployment controls. Of those, serving an ensemble or a multi-stage inference path as one versioned deployment rather than as a chain of separate services and running genuine production experiments where a share of live traffic goes to a candidate model and the results are compared are not what Vitess is typically brought in for.
What can Seldon do that Vitess cannot?
Seldon covers Kubernetes custom resources, Inference graphs, Traffic strategies, Open Inference Protocol. Vitess covers Horizontal Sharding, Connection Pooling, Query Routing, Online Schema Changes.

Answered from the vendors’ own pages

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.

Vitess: Is Vitess free to use?

Yes. Vitess is completely free and open source under the Apache 2.0 license. It is a graduated CNCF project with no licensing costs or pricing tiers.

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.

Vitess: What databases does Vitess support?

Vitess supports MySQL and MariaDB as backend databases. It acts as a middleware layer that adds sharding and orchestration capabilities on top of these databases.

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.

Vitess: Does Vitess require Kubernetes to run?

No. Vitess can run on Kubernetes using the Vitess Operator, but it can also be deployed on traditional infrastructure. Kubernetes integration is optional and provides additional automation benefits.

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.

Vitess: How does Vitess handle cross-shard transactions?

Vitess supports distributed transactions across shards, but they require queries to be routed through the sharding key. Transactions without a proper sharding key can result in slower performance.

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.

Vitess: Does Vitess enforce foreign key constraints?

Vitess does not enforce foreign key constraints across shards by default. Referential integrity must be managed at the application layer, though per-database support can be enabled with limitations.

Source
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