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Abhiraj Adhikary
Abhiraj Adhikary

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Apache Fluss: Architecting the Streaming-First Persistent Data Stack

Traditional Modern Data Stacks are inherently fragmented, relying on separate silos for streaming, batch processing, lakehouses, and AI systems. This fragmentation forces organizations to maintain multiple copies of data, increases operational complexity, and creates expensive retention overhead in systems like Kafka. Additionally, analytical freshness suffers because data pipelines are often batch-oriented and disconnected from real-time applications.

As real-time AI systems, recommendation engines, fraud detection, and agentic workflows become business-critical, the industry is shifting from batch-first architectures toward streaming-first persistent systems, where streams and tables converge into a unified abstraction.

This new architectural paradigm enables organizations to process, store, query, and serve data continuously without maintaining separate infrastructures for streaming and analytics.


The Core Architecture: How It Works

This unified ecosystem moves away from traditional broker-centric designs and introduces a streaming-native analytical storage model.

1. Ingestion Layer (CDC, IoT, Logs)

Continuous event streams such as:

  • Change Data Capture (CDC)
  • IoT telemetry
  • Application logs
  • Clickstream events

are written directly into the storage core, bypassing heavy broker retention dependencies.

This reduces:

  • Kafka storage costs
  • Operational overhead
  • Data duplication across systems

2. Storage Core — Apache Fluss

At the center of the architecture sits Apache Fluss, which acts as a real-time streaming storage engine.

Responsibilities

  • Maintains streaming tables
  • Stores changelogs
  • Preserves low-latency hot data
  • Automatically tiers cold data into object storage (S3/OBS)

Key Innovation

Instead of treating streams as temporary transport layers, Fluss treats them as a persistent analytical substrate.

This enables:

  • Real-time reads/writes
  • Stateful streaming
  • Stream-table unification
  • Efficient historical access

3. Compute Layer — Apache Flink SQL

Apache Flink SQL performs stateful transformations and real-time analytics.

Major Capability: Union Reads

Flink can simultaneously query:

  • Hot data from Fluss
  • Historical cold data from the lakehouse

This creates a seamless analytical experience across real-time and historical datasets.

Typical Workloads

  • Sessionization
  • Fraud detection
  • Feature engineering
  • Aggregations
  • Real-time ETL

4. Persistence Layer — Apache Iceberg

Cold and immutable historical datasets are persisted into Apache Iceberg.

Benefits

  • ACID table guarantees
  • Schema evolution
  • Time travel
  • Partition optimization
  • Open table format interoperability

Catalogs such as:

  • Nessie
  • Polaris

manage metadata and versioning for Iceberg tables.


5. Query & OLAP Layer

Specialized analytical engines accelerate different workloads.

Databend

Optimized for:

  • High-throughput OLAP
  • Warehouse-scale analytical queries
  • Concurrent workloads

Dremio

Provides:

  • Semantic acceleration
  • BI query optimization
  • Lakehouse exploration

Trino

Enables:

  • Federated SQL querying
  • Cross-platform analytics
  • Distributed query execution

Together, these engines provide a flexible analytical ecosystem over the unified lakehouse.


6. AI & Vector Layer

Modern AI applications require real-time embeddings and semantic retrieval systems.

Vector Databases

  • Qdrant
  • Milvus

store embeddings generated from streaming pipelines.

Use Cases

  • Recommendation systems
  • Semantic search
  • Retrieval-Augmented Generation (RAG)
  • Real-time personalization
  • Agent memory systems

This enables AI systems to continuously consume fresh streaming data.


7. Infrastructure & Operations Layer

The entire ecosystem is deployed using cloud-native infrastructure.

Kubernetes

Provides:

  • Container orchestration
  • Horizontal scaling
  • Self-healing deployments

Terraform

Enables:

  • Infrastructure-as-Code (IaC)
  • Reproducible environments
  • Automated provisioning

Airflow

Handles:

  • Workflow orchestration
  • Batch coordination
  • Dependency management

Implementation & Practical Use Case

Real-Time E-Commerce Platform

Consider a large-scale e-commerce system.

Data Sources

  • CDC events from transactional databases
  • User clickstreams
  • Product interactions
  • Payment events
  • Inventory updates

Processing Flow

  1. CDC and clickstream events continuously flow into Apache Fluss.
  2. Apache Flink computes:
  • Live sessions
  • Fraud signals
  • User activity windows
  • Recommendation features
    1. Hot operational data remains in Fluss for low-latency access.
    2. Historical data persists into Apache Iceberg.
    3. Dremio accelerates BI dashboards over the lakehouse.
    4. Databend powers heavy OLAP analytics workloads.
    5. Qdrant stores vector embeddings for personalized recommendations.

Strategic Evaluation

Key Advantages

Reduced Costs

  • Minimizes Kafka retention overhead
  • Reduces unnecessary data duplication
  • Uses cheaper object storage for cold data

Unified Processing Logic

Stream-table unification enables Flink to seamlessly access both:

  • Real-time streaming data
  • Historical lakehouse data

without separate architectures.

AI-Ready Infrastructure

Native support for:

  • Vector databases
  • Real-time feature pipelines
  • Streaming embeddings
  • RAG architectures

makes the system ideal for modern AI workloads.

Cloud-Native Scalability

Designed for:

  • Kubernetes deployments
  • Remote object storage
  • Elastic compute scaling
  • Multi-cloud infrastructure

Conclusion

The rise of Apache Fluss signals a fundamental architectural shift in modern data engineering.

Streaming is no longer treated as a transient transport mechanism — it is becoming the primary abstraction for data persistence and analytics.

By collapsing the traditional boundaries between ingestion, storage, streaming, analytics, and AI, this architecture provides the low-latency foundation required for:

  • Real-time intelligence
  • Continuous feature freshness
  • AI-native applications
  • Agentic systems
  • Next-generation recommendation engines

This unified streaming-first ecosystem represents the future of modern data platforms.

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