Goodbye Zookeeper, Hello KRaft

Written by
Sugam Sharma
.
Co-Founder & CIO
Published on
Apr 2, 2025
Technology

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What’s Changed in Kafka and What It Means for Real-Time Data Platforms

Apache Kafka 4.0 marks a pivotal shift in the architecture of the world’s most widely adopted event streaming platform. The most significant change?
The complete removal of ZooKeeper in favor of a native consensus protocol called KRaft (Kafka Raft). This transition has been years in the making — and with 4.0, the future is finally here.

Let’s dive into what changed, why it matters, and how platforms like Condense are already ahead of the curve by operationalizing this transformation — and more — for industry-specific use cases.

The Role of ZooKeeper (Before Kafka 4.0)

Historically, Kafka used Apache ZooKeeper for:

  • Storing and managing metadata (e.g., broker list, partitions, topic configs)

  • Controller election and cluster coordination

  • Access control policies and cluster-wide state

However, ZooKeeper came with several challenges:

  • Operational overhead (managing and scaling two distributed systems)

  • Fragile failover during controller elections

  • Latency during metadata propagation

  • Complexity in upgrades and security configurations

KRaft: Kafka Raft Metadata Mode

KRaft (Kafka Raft) eliminates the ZooKeeper dependency and implements a native, quorum-based metadata system within Kafka itself.

What Changed with KRaft:

Feature

Zookeeper Based Kafka

KRaft Based Kafka (4.0+)

Metadata Management

Handled by ZooKeeper

Handled by Kafka controllers using Raft

Controller Election

Managed by ZooKeeper

Built-in Raft consensus protocol

System Complexity

Two systems to manage

Kafka is now standalone

Startup Time

Slower due to ZooKeeper handshake

Significantly faster cluster boot

Scalability

Harder to scale ZooKeeper clusters

Easier to scale KRaft controllers

Upgrade Path

Multi-step with ZK version dependency

Simplified Kafka-native upgrades

Benefits of KRaft

  • Simplified Deployment: No external coordination system required

  • Better Resilience: Faster failover and self-healing metadata replication

  • Operational Efficiency: Uniform config, easier security, and unified logs

  • Faster Controller Recovery: Lower downtime under broker failure

  • Improved Developer Experience: Single system to monitor and configure

Migration Note

Kafka 4.0 is KRaft-only — there is no fallback to ZooKeeper.
If you’re still running ZooKeeper-based clusters:

  1. Migrate to KRaft mode in Kafka 3.5–3.9

  2. Verify metadata migration and topic integrity

  3. Then upgrade to Kafka 4.0

Why This Shift Matters

KRaft is not just about removing ZooKeeper — it’s about transforming Kafka into a self-contained, enterprise-grade, cloud-native platform.

It opens the door for:

  • More elastic deployments

  • Multi-tenant streaming services

  • Better security integration

  • Cleaner DevOps pipelines

But here’s the challenge: Kafka is still a foundational layer — not a business solution.

Turning KRaft-enabled Kafka into a vertical-ready, decision-driving system still requires time, expertise, and tooling.

Condense: Built for the Post-ZooKeeper Era

Condense is a real-time event processing platform that has been built on modern Kafka-native foundations from the beginning — with KRaft-mode compatibility fully baked in.

But more importantly, Condense doesn’t stop at infrastructure. It provides what Kafka lacks: Verticalized intelligence and actionable outcomes.

Why Condense is Ahead

While Kafka 4.0 offers a cleaner, faster backbone, Condense adds the muscle and brain on top of it:

Kafka (4.0)

Condense

KRaft Metadata

Fully adopted, zero-ZooKeeper design from day one

Share Groups (KIP-932)

Enhanced with per-entity message routing

Observability via metrics (KIP-1076)

Real-time dashboards, latency tracing, anomaly detection

Event streams

Enriched with schema-aware pipelines, low-code transforms

Raw ingestion

Transformed into contextual, domain-specific signals

Developer APIs

Combined with UI-based orchestration and trigger workflows

Vertical Intelligence: Where Condense Delivers the Edge

Kafka’s improvements make it easier to stream and scale — but they don’t deliver business context.

Condense bridges that gap with:

  • Mobility: Route deviation alerts, geofencing triggers, language-localized notifications

  • Manufacturing: Predictive maintenance pipelines, downtime alerting, machine rule engines

  • Energy: Real-time load balancing, outage detection, automated restoration flows

  • Finance: Fraud event detection, AML pipelines, audit-ready event trails

The transition from ZooKeeper to KRaft is more than just a technical milestone — it’s a turning point in Kafka’s evolution toward simplification, reliability, and scale.

But adopting Kafka 4.0 is just the beginning. Condense takes Kafka further — turning raw event streams into verticalized, real-time intelligence. If you’re looking to operationalize Kafka 4.0 not just at the infrastructure layer but across vertical workflows and outcomes, Condense is built for exactly that future — and it’s already delivering it today.

Ready to Build Real-Time, Contextual Intelligence with Kafka 4.0 at the Core?

Contact Us for a demo, architecture consultation, or integration guide.

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