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Lakestream: The Open Stream Storage

Streams on object storage, integrated with your lakehouse. Ursa is our implementation.

Stream Storage on Object Storage

Leaderless and diskless, implemented by Ursa.

Integrated with Your Lakehouse

Streams sit next to your Iceberg and Delta tables.

Kafka and Pulsar on One Foundation

The protocol is an interface, not a data silo.

What's New

Serverless Kafka Private Preview

StreamNative Cloud now supports Serverless Kafka in Private Preview — a fully managed, elastic, pay-as-you-go Kafka experience with topic-level performance profiles.

Read Announcement

HOW IT WORKS

One Open Storage Layer for Every Protocol

Lakestream solves interoperability in storage, not by translating between protocols. Streams and their metadata live on object storage next to your lakehouse tables, and stateless Kafka, Pulsar, REST, and gRPC servers serve the same data.

Lakestream open stream storage diagram

VISION

Streamhouse and Lakehouse, Built on the Same Open Infrastructure

Both stand on object storage, open table formats, and catalogs. The lakehouse needed one thing to be open: tables. A Streamhouse also needs the stream to be open. Lakestream is that open stream storage, so streams and tables share the same ground instead of living in separate systems.

Stream-Table Duality, Built in

Every stream is simultaneously a table — with offset monotonicity, eventual visibility, and schema consistency guarantees built in.

Zero-ETL by Design

Events are written once in open formats on object storage, so analytics and ML read what streaming apps produce without a separate stream-to-table pipeline.

Same Ground, Different Jobs

The lakehouse is data to analyze the business; a Streamhouse is data to run it. Lakestream lets both work from the same open storage.

DEEP DIVE

Inside Lakestream

Lakestream separates stream storage, stream metadata, and protocol serving, so each scales independently while sharing the same governed data.

Stream Storage — Implemented by Ursa

Stream Storage — Implemented by Ursa

Lakestream stores streams on object storage, and Ursa is our implementation: leaderless and diskless, with a distributed Write-Ahead Log (WAL) for low-latency streaming and data compacted to Parquet for analytics.

WAL for sub-millisecond write latency

Leaderless, diskless — no broker disks, no cross-AZ replication

KEY BENEFITS

Why Open Stream Storage Matters

Up to 95% Cost Reduction

Object storage eliminates cross-AZ replication. At 5 GB/s throughput, implementations show up to 95% cost savings versus traditional broker-based Kafka.

Leaderless & Diskless

No leader elections, no partition rebalancing. Stateless protocol servers scale horizontally — add or remove like web servers.

Open Formats

Data lives in Parquet, Iceberg, and Delta Lake on your object storage. No proprietary segment format, full query engine portability.

Stream-Table Duality

Every stream is simultaneously a table with built-in consistency guarantees: offset monotonicity, eventual visibility, and schema consistency.

Multi-Protocol, Single Data

Kafka, Pulsar, REST, and gRPC serve the same streams simultaneously. The protocol is a choice of interface, not a choice of data silo.

PROOF POINTS

Lakestream in Practice

Lakestream is shipping today. Ursa is our implementation of it, and Ursa for Kafka runs native Apache Kafka on it.

Ursa

Ursa

Cloud-Native Storage Engine

Our implementation of Lakestream: a cloud-native storage engine with a WAL + Parquet two-tier model on object storage that makes lakehouse-native streaming possible.

VIEW DETAILS
Ursa For Kafka (UFK)

Ursa For Kafka (UFK)

Native Apache Kafka on Lakestream

Native Apache Kafka — not compatible, native. UFK takes Apache Kafka 4.0+ and replaces local disk storage with Lakestream, delivering leaderless, diskless Kafka with up to 95% cost reduction.

VIEW DETAILS

Ursa Awarded Best Industry Paper

Read our award-winning paper on Ursa, the first lakehouse-native, leaderless streaming engine for Kafka.

READ MORE
VLDB 2025 Best Industry Paper

Experience Lakestream

  • Spin up a Kafka or Pulsar cluster on StreamNative in minutes.
  • Every topic is a lakehouse table — no connectors, no ETL.
  • Up to 95% cost reduction with leaderless, diskless architecture.