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Databases · head to head

DataStax vs Solace PubSub+

DataStax logo

DataStax

Databases

The real-time data company for AI applications

From
Free
Rated
-
Full reviewWebsite
Solace PubSub+ logo

Solace PubSub+

Databases

Multi-protocol event broker sold as software, cloud service or a hardware appliance

From
Free
Rated
-
Full reviewWebsite

The short version

  • Each has a real cost: DataStax dataStax's own Astra DB documentation states the Enterprise plan is an annual, contract-based plan with negotiated pricing, meaning list prices are not published for that tier; Solace PubSub+ no pricing is published at any tier, so evaluation requires a sales engagement before you can even judge whether it is in budget, and broker tier sizing determines cost in ways buyers frequently get wrong.
  • They diverge on capability: DataStax covers Cassandra Compatible, Solace PubSub+ covers Multi-protocol broker.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

Only the attributes on which DataStax and Solace PubSub+ actually diverge.

Attributes where DataStax and Solace PubSub+ differ
AttributeDataStaxSolace PubSub+
Pricing modelfreemiumquote
PlatformsWeb, Aws, Azure, GcpLinux, Docker, Kubernetes, Cloud, Hardware appliance
Founded2010Unknown

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

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 DataStax

  • Cassandra Compatible
  • Vector Search
  • Serverless
  • Multi-cloud
  • Streaming
  • CDC
  • GraphQL API
  • LangChain

Only in Solace PubSub+

  • Multi-protocol broker
  • Dynamic message routing
  • Hardware appliance
  • Event Portal
  • Guaranteed delivery
  • Mission Control
  • Topic hierarchies and wildcards
  • Kafka and MQ bridging

What people use each for

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

DataStax

  • Real-time applicationsnot Solace PubSub+
  • Content managementnot Solace PubSub+
  • User profilesnot Solace PubSub+
  • Mobile backendsnot Solace PubSub+
  • Cachingnot Solace PubSub+

Solace PubSub+

  • A bank building an event mesh across regions where a Java JMS application and an MQTT mobile client must share the same topic spacenot DataStax
  • An exchange or trading platform with a latency budget that needs the hardware appliance rather than a software brokernot DataStax
  • An airline distributing operational events to ground systems, aircraft and partner APIs over different protocolsnot DataStax
  • A manufacturer bridging factory MQTT telemetry into an enterprise Kafka estate without writing translation servicesnot DataStax

Where each one falls short

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

DataStax

  • DataStax's own Astra DB documentation states the Enterprise plan is an annual, contract-based plan with negotiated pricing, meaning list prices are not published for that tier
  • DataStax's Astra DB documentation directs Standard plan customers to IBM's watsonx.data pricing for exact consumption-based rates following the DataStax/IBM deal, rather than publishing them on DataStax's own site

Solace PubSub+

  • No pricing is published at any tier, so evaluation requires a sales engagement before you can even judge whether it is in budget, and broker tier sizing determines cost in ways buyers frequently get wrong.
  • The free Standard edition has hard capacity and support limits, which makes it useful for development but means any real deployment triggers a commercial negotiation.
  • The proprietary SMF protocol gives the best performance and feature coverage, so teams that lean on it acquire real switching costs even though open protocols are supported.
  • Operating a self-managed high availability broker pair with disaster recovery is a specialist task, and Solace expertise is scarce in the hiring market compared with Kafka skills.
  • Event Portal and Mission Control are licensed as part of platform packages, so the governance tooling that makes an event mesh manageable is not simply included with the broker.

Pricing, plan by plan

DataStax

Free
  • FreeFree
    • 5GB storage
    • 40M read/write ops
    • Vector search
  • Pay As You GoFree
    • Usage-based pricing
    • Multi-region
    • Enterprise support

Solace PubSub+

Free
  • Software Event Broker StandardFree
    • Free for production within capacity limits
    • Single node, capped connections and queues
    • No vendor support
  • Solace Cloud$undefined/year
    • Managed brokers in tiers from ENT-250 to ENT-100K
    • Foundation, Accelerate and Scale platform packages
    • Fixed subscription or annual consumption drawdown
  • Software Enterprise self-managed$undefined/year
    • Deploy in your own Kubernetes, VMs or data centre
    • High availability and disaster recovery
    • Support with SLA
  • Hardware appliance$undefined/year
    • Purpose-built appliance with FPGA message offload
    • Deterministic low latency
    • Sold with support contract

Which should you pick?

Choose DataStax if

  • You need cassandra compatible.
  • You want to start without paying.
  • You work on Web, Aws, Azure, Gcp.
  • You also want vector search.
DataStax review

Choose Solace PubSub+ if

  • You need multi-protocol broker.
  • You want to start without paying.
  • You work on Linux, Docker, Kubernetes, Cloud, Hardware appliance.
  • You also want dynamic message routing.
Solace PubSub+ review

Questions people ask

Is DataStax or Solace PubSub+ better?
Neither clearly leads. DataStax starts at Free and Solace PubSub+ at Free, and user ratings are close enough to be indistinguishable. Choose on capability and platform support.
Which is cheaper, DataStax or Solace PubSub+?
DataStax starts at Free and Solace PubSub+ at Free.
Does DataStax or Solace PubSub+ run on more platforms?
DataStax runs on Web, Aws, Azure, Gcp. Solace PubSub+ runs on Linux, Docker, Kubernetes, Cloud, Hardware appliance.
Can I use DataStax for free?
Both have a free tier, so you can try either at no cost before committing.
What is DataStax best used for?
DataStax 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 Solace PubSub+ is typically brought in for.
What can DataStax do that Solace PubSub+ cannot?
DataStax covers Cassandra Compatible, Vector Search, Serverless, Multi-cloud. Solace PubSub+ covers Multi-protocol broker, Dynamic message routing, Hardware appliance, Event Portal.

Answered from the vendors’ own pages

DataStax: Is DataStax available as a managed service?

Yes, DataStax is available as Astra DB, a managed database service. Users can sign up for Astra DB directly to create accounts and access the platform.

Source
Solace PubSub+: Is there a free version of Solace?

Yes, the Standard edition of the software event broker is free for production within capacity limits, with no vendor support.

DataStax: How is DataStax priced?

DataStax (now part of IBM) does not publish pricing on its documentation homepage. Pricing information would need to be obtained through the Astra DB signup page or by contacting IBM directly.

Source
Solace PubSub+: Does Solace publish prices?

No. Cloud, software and appliance are all quoted, based on broker tier from ENT-250 to ENT-100K and licensing model.

DataStax: Is there an enterprise licensing option?

DataStax is now part of IBM. Enterprise customers should contact IBM directly for licensing agreements and enterprise-specific pricing.

Source
Solace PubSub+: Why buy an appliance in 2026?

Deterministic low latency with message processing offloaded to hardware, which matters in capital markets and little elsewhere.

DataStax: Can I try DataStax without an account?

To use DataStax Astra DB, account creation is required. The documentation does not mention a free trial or demonstration environment that does not require signup.

Source
Solace PubSub+: Can it replace Kafka?

Not for log retention and stream reprocessing. It is stronger at multi-protocol routing and guaranteed delivery, and the two are often bridged.

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