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Hazelcast vs Tarantool

Hazelcast: A Java in-memory data grid and stream processor that embeds in your app or runs as a cluster. Tarantool: In-memory database and Lua application server in one process, with an optional disk engine.

key differences

  • Horizontal scaling is native in Hazelcast and addon in Tarantool.
  • Transactions: Hazelcast offers limited ACID; Tarantool offers full.
  • Only Hazelcast has joins, vector search, change data capture, ttl / expiry, pub/sub.
  • Only Tarantool has geospatial, triggers, role-based access.
  • Hazelcast can run embedded in your application process.

choose hazelcast for

  • +Shared low-latency state for microservices
  • +Fraud detection and payment stream processing
  • +Web session clustering for Java app servers
  • +Distributed caching in front of RDBMS

best at · Cache, Sessions, Streaming

choose tarantool for

  • +Low-latency transactional caches that are also the source of truth
  • +Session and user-profile storage for high-traffic sites
  • +Queues and real-time counters
  • +Fintech and telecom billing hot paths

best at · OLTP, Cache, Sessions

HazelcastA Java in-memory data grid and stream processor that embeds in your app or runs as a cluster.
TarantoolIn-memory database and Lua application server in one process, with an optional disk engine.
overview
Primary model
Key-Value
Key-Value
Also supports
Document, Vector
Document, Relational
Type
Database engine
Database engine
Status
Active
Active
Developer
Hazelcast, Inc.
VK
First release
2008
2008
Latest version
5.7.0 (May 12, 2026)
3.9.0 (Oct 26, 2026)
License
Open source (permissive)Apache 2.0 (Community); Hazelcast Community License for some modules
Open source (permissive)BSD 2-Clause License
Free tier
✓
✓
popularity
WhichDB Score
33.5
21.2
Rank
#63
#140
GitHub stars
6.6K
3.7K
Stack Overflow questions
2.9K
219
scale & guarantees
Comfortable data size
Medium (≤ 10 TB)
Medium (≤ 10 TB)
Horizontal scaling
Native
Addon
Multi-region
Active active
Read replicas
ACID
Limited
Full
Consistency
Eventual, Strong
Strong, Eventual
Schema
Flexible
Flexible
Architecture
In memory, Distributed, Embedded, Client server
In memory, Primary replica, Multi primary, Client server
deployment
Self-hosted
✓
✓
Vendor-managed cloud
—
—
Serverless
—
—
Embedded
✓
—
Edge
—
—
Clouds
AWS, Google Cloud, Azure
–
capabilities
Transactions
✓
✓
Joins
✓
—
Secondary indexes
✓
✓
Full-text search
—
—
Vector search
✓
—
Geospatial
—
✓
JSON
✓
✓
Change data capture
✓
—
Triggers
—
✓
Stored procedures
✓
✓
Materialized views
—
—
TTL / expiry
✓
—
Pub/Sub
✓
—
Columnar storage
—
—
In-memory
✓
✓
Durable persistence
✓
✓
Compression
✓
✓
Encryption at rest
—
—
Role-based access
—
✓
Time travel
—
—
Branching
—
—
Online schema changes
—
—
Streaming ingest
✓
—
Offline sync
—
—
Runs in WebAssembly
—
—
interfaces
Query languages
SQL, Predicate API, Jet Pipeline API
Lua, SQL
Client languages
Java, C#, C++, Python, JavaScript, Go
Lua, Go, Java, Python, C, C++, JavaScript, PHP
Best for
Cache, Sessions, Streaming, Real-time analytics
OLTP, Cache, Sessions, Queue
Add more to this comparisonNot sure either fits? Try smart match

Hazelcast vs Tarantool: FAQ

What is the difference between Hazelcast and Tarantool?

Hazelcast: A Java in-memory data grid and stream processor that embeds in your app or runs as a cluster. Tarantool: In-memory database and Lua application server in one process, with an optional disk engine. Horizontal scaling is native in Hazelcast and addon in Tarantool. Transactions: Hazelcast offers limited ACID; Tarantool offers full. Only Hazelcast has joins, vector search, change data capture, ttl / expiry, pub/sub.

When should I choose Hazelcast over Tarantool?

Choose Hazelcast for shared low-latency state for microservices; fraud detection and payment stream processing; and web session clustering for Java app servers. Choose Tarantool for low-latency transactional caches that are also the source of truth; session and user-profile storage for high-traffic sites; and queues and real-time counters.

Is Hazelcast or Tarantool more popular?

Hazelcast ranks #63 on the WhichDB Score (33.5/100) and Tarantool ranks #140 (21.2/100). Popularity is not fit: check the requirements that matter for your project.

Are Hazelcast and Tarantool open source?

Yes. Hazelcast is open source. License: Apache 2.0 (Community); Hazelcast Community License for some modules. Yes. Tarantool is open source. License: BSD 2-Clause License.