ClickHouse Keeper

Open-source coordination that scales

ClickHouse Keeper solves the well-known drawbacks of ZooKeeper and makes many additional improvements.

Join us in building the future of distributed consensus.
ClickHouse Keeper

Coordination without the drawbacks

In order to overcome some shortcomings of ZooKeeper, we started building a ClickHouse native Keeper from scratch based on our own requirements, optimized for usage in ClickHouse.


Easier setup and operation


No overflow issues


Better compression


Faster recovery


Less memory used


Additional guarantees


A replacement for ZooKeeper?

Keeper is a drop-in replacement for ZooKeeper written in C++, with a fully compatible client protocol and the same data model, and features these improvements


Compatible client protocol (all clients work out of the box)


The same state machine (data model)


Better guarantees (optionally allows linearizable reads)


Uses Raft algorithm (NuRaft implementation)


Optional TLS for clients and internal communication


When to use ClickHouse Keeper?

  • Most of your request are writes
  • Efficient memory utilization matters
  • Your project isn’t part of the Java ecosystem
  • You are managing a ClickHouse cluster

When NOT to use ClickHouse Keeper?

  • Most of your request are reads
  • You require scalability with a read-heavy workload
  • Java-based components are important to you
C++ + RAFT

Keep your system afloat with RAFT

ZooKeeper Implementation

ZooKeeper is implemented in Java and its coordination algorithm, ZooKeeper Atomic Broadcast (ZAB), doesn't provide linearizability guarantees for reads.

ClickHouse Keeper Implementation

Unlike ZooKeeper, ClickHouse Keeper is written in C++ and uses the RAFT algorithm implementation. This algorithm allows linearizability for reads and writes, and has several open-source implementations in different languages.

Start using ClickHouse in minutes

Install ClickHouse for MacOS, Linux, and FreeBSD.

curl | sh

Or install for Windows, Docker or see other install options.

Watch this getting started video to learn more about ClickHouse.

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