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Databases · head to head

Qdrant vs Solace PubSub+

Qdrant logo

Qdrant

Databases

High-performance vector database for similarity search and embedding-based retrieval

From
Free
Rated
-
Solace PubSub+ logo

Solace PubSub+

Databases

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

From
Free
Rated
-

The short version

  • Each has a real cost: Qdrant free tier extremely limited (0.5 vCPU, 1GB RAM, 4GB disk); suitable only for experiments; 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.
  • Prices and features above were last checked on 31 August 2026.

Where they differ

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

Attributes where Qdrant and Solace PubSub+ differ
AttributeQdrantSolace PubSub+
Pricing modelfreemiumquote
PlatformsCloud (AWS, GCP, Azure), Kubernetes, Self-hosted, Edge (beta), Serverless (coming)Linux, Docker, Kubernetes, Cloud, Hardware appliance

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 Qdrant

Nothing recorded that Solace PubSub+ does not also cover.

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.

Qdrant

  • Retrieval-augmented generation (RAG) backends for LLM applicationsnot Solace PubSub+
  • Semantic search across large document corporanot Solace PubSub+
  • Multimodal retrieval (text, images, video) for recommendation systemsnot Solace PubSub+
  • Similarity-based product or content recommendationsnot Solace PubSub+
  • Real-time vector indexing for streaming embedding datanot 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 Qdrant
  • An exchange or trading platform with a latency budget that needs the hardware appliance rather than a software brokernot Qdrant
  • An airline distributing operational events to ground systems, aircraft and partner APIs over different protocolsnot Qdrant
  • A manufacturer bridging factory MQTT telemetry into an enterprise Kafka estate without writing translation servicesnot Qdrant

Where each one falls short

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

Qdrant

  • Free tier extremely limited (0.5 vCPU, 1GB RAM, 4GB disk); suitable only for experiments
  • Standard and Premium pricing usage-based; specific costs not published; requires calculator or quote
  • Requires understanding of embeddings and vector search concepts; not suitable for SQL-only teams
  • Early-stage serverless offering (coming soon) suggests maturity gaps in that deployment model

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

Qdrant

Free
  • FreeFree
    • Single-node cluster
    • 0.5 vCPU
    • 1GB RAM
  • Standard$undefined/usage-based
    • Dedicated resources
    • Flexible scaling
    • High availability
  • Premium$undefined/minimum spend
    • SSO and SAML
    • Private VPC links
    • 99.9% uptime SLA

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 Qdrant if

  • You want to start without paying.
  • You work on Cloud (AWS, GCP, Azure), Kubernetes, Self-hosted, Edge (beta), Serverless (coming).

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.

Questions people ask

Is Qdrant or Solace PubSub+ better?
Neither clearly leads. Qdrant 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, Qdrant or Solace PubSub+?
Qdrant starts at Free and Solace PubSub+ at Free.
Does Qdrant or Solace PubSub+ run on more platforms?
Qdrant runs on Cloud (AWS, GCP, Azure), Kubernetes, Self-hosted, Edge (beta), Serverless (coming). Solace PubSub+ runs on Linux, Docker, Kubernetes, Cloud, Hardware appliance.
Can I use Qdrant for free?
Both have a free tier, so you can try either at no cost before committing.
What is Qdrant best used for?
Qdrant is most often used for retrieval-augmented generation (rag) backends for llm applications, semantic search across large document corpora, multimodal retrieval (text, images, video) for recommendation systems, similarity-based product or content recommendations. Of those, retrieval-augmented generation (rag) backends for llm applications and semantic search across large document corpora are not what Solace PubSub+ is typically brought in for.
What can Qdrant do that Solace PubSub+ cannot?
Solace PubSub+ covers Multi-protocol broker, Dynamic message routing, Hardware appliance, Event Portal.

Answered from the vendors’ own pages

Qdrant: Can I use Qdrant for free?

Yes, Qdrant offers a free tier that provides a single node cluster with 0.5 vCPU, 1GB RAM, and 4GB disk space. It includes free cloud inference with selected models and is described as free forever for testing and prototypes.

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.

Qdrant: How is Qdrant Cloud billing calculated?

Billing is calculated based on actual resource usage during each billing period. You are charged hourly for compute (vCPU), memory (GB), storage (GB), backups, and any paid inference tokens used.

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.

Qdrant: What happens if I scale beyond the free tier?

The Standard Tier uses the same usage-based billing model as the free tier but adds features like dedicated resources with flexible scaling, highly available setups with backup and disaster recovery, and a 99.5% uptime SLA.

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.

Qdrant: What SLA does Qdrant offer?

The Standard Tier provides 99.5% uptime SLA. The Premium Tier, which requires a minimum spend for enterprises, offers 99.9% uptime SLA along with single sign-on and private VPC links.

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.

Qdrant: Are there dedicated cloud infrastructure options?

Yes, Qdrant offers Hybrid Cloud (runs on your infrastructure) and Private Cloud (complete isolation) options, both with custom pricing that requires contacting the sales team.

Source
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