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Apache Kudu

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by Apache Software Foundation · since 2016 · also known as Kudu

Columnar storage engine for fast analytics on fast-changing data, paired with Impala or Spark.

columnar / olaprelationaldatabase engineopen source (permissive)mature
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Overview

Apache Kudu is a distributed columnar storage engine from the Hadoop ecosystem that fills the gap between HDFS/Parquet (fast scans, no updates) and HBase (fast updates, slow scans). Tables have primary keys and support inserts, updates and deletes with low latency, replicated with Raft, while keeping columnar scan performance. It has no SQL of its own; Impala, Spark or Presto/Trino provide the query layer. Kudu remains useful in Cloudera estates for mutable analytic tables, but releases are infrequent and Iceberg or Paimon now cover many of the same needs.

Real-time analyticsAnalytics (OLAP)Time-series data

Strengths & trade-offs

Strengths

  • +Low-latency inserts, updates and deletes on columnar tables
  • +Raft replication gives strong consistency and automatic failover
  • +Fast scans for analytics via Impala and Spark
  • +Simpler than combining HBase with Parquet for mutable data

Trade-offs

  • −No query engine of its own
  • −Slow release cadence and shrinking community
  • −Tied to the Hadoop/Cloudera ecosystem
  • −Not designed for object storage

Great for

  • +Mutable fact tables in Cloudera
  • +Near-real-time analytics with Impala
  • +Time-series with updates

Think twice for

  • −Cloud-native object-storage lakehouses
  • −Standalone SQL database use
  • −OLTP with complex transactions

Capabilities

Native or official first-party support · 6 of 25 tracked

✓Columnar storage
✓Durable persistence
✓Compression
✓Encryption at rest
✓Role-based access
✓Online schema changes
–Transactions
–Joins
–Secondary indexes
–Full-text search
–Vector search
–Geospatial
–JSON
–Change data capture
–Triggers
–Stored procedures
–Materialized views
–TTL / expiry
–Pub/Sub
–In-memory
–Time travel
–Branching
–Streaming ingest
–Offline sync
–Runs in WebAssembly

Scale & consistency

Comfortable data size
Large · ≤ 1 PB
Horizontal scaling
Native
Multi-region
No
Transactions
Limited ACID
Consistency
Strong
Schema
Strict
Architecture
Distributed
Query languages
Impala SQL, Spark SQL, Kudu client API

Tablets are hash/range partitioned across tablet servers and replicated with Raft.

Deployment

Self-hosted Vendor-managed cloud Serverless Embedded Edge Kubernetes operator

Ecosystem

apis & protocolsC++ client, Java client, Python client
client languagesC++, Java, Python

Alternatives to Apache Kudu

Compare all→
Apache ImpalaRelational29.0

Low-latency MPP SQL engine for Hadoop, Kudu and Iceberg tables, developed largely by Cloudera.

apache-kudu vs apache-impala →
Apache PaimonColumnar / OLAP14.2

Streaming lakehouse table format with LSM-based upserts and changelogs, born in Apache Flink.

apache-kudu vs apache-paimon →
Apache HBaseWide-Column26.6

Hadoop's Bigtable clone: strongly consistent wide-column tables on top of HDFS.

apache-kudu vs apache-hbase →
ClickHouseColumnar / OLAP69.8

Open-source columnar OLAP database known for very fast aggregations over billions of rows.

apache-kudu vs clickhouse →
StarRocksColumnar / OLAP15.6

MPP OLAP database with a fast vectorized engine, real-time upserts and native lakehouse queries.

apache-kudu vs starrocks →
InMemory.NetColumnar / OLAP0.2

Commercial in-memory columnar SQL engine for .NET that speeds up reporting over hundreds of millions of rows.

apache-kudu vs inmemory-net →

Apache Kudu FAQ

What is Apache Kudu?

Apache Kudu is a columnar / OLAP database by Apache Software Foundation, first released in 2016. Apache Kudu is a distributed columnar storage engine from the Hadoop ecosystem that fills the gap between HDFS/Parquet (fast scans, no updates) and HBase (fast updates, slow scans). Tables have primary keys and support inserts, updates and deletes with low latency, replicated with Raft, while keeping columnar scan performance. It has no SQL of its own; Impala, Spark or Presto/Trino provide the query layer. Kudu remains useful in Cloudera estates for mutable analytic tables, but releases are infrequent and Iceberg or Paimon now cover many of the same needs.

Is Apache Kudu open source?

Yes. Apache Kudu is open source. License: Apache License 2.0.

Does Apache Kudu support ACID transactions?

Partly. Apache Kudu offers limited ACID guarantees (for example, single-record or single-partition transactions), with strong consistency.

Does Apache Kudu scale horizontally?

Apache Kudu scales horizontally out of the box, with built-in sharding or partitioning. It is comfortable at large scale (≤ 1 PB).

How can I run Apache Kudu?

You can self-host it.

What is Apache Kudu best for?

Apache Kudu is a strong fit for mutable fact tables in Cloudera, near-real-time analytics with Impala and time-series with updates. Think twice for cloud-native object-storage lakehouses.

What are the best alternatives to Apache Kudu?

Common alternatives to Apache Kudu include Apache Impala, Apache Paimon, Apache HBase, ClickHouse and StarRocks. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.

How popular is Apache Kudu?

Apache Kudu ranks #176 of 844 databases on the WhichDB Score (18.6/100), and #16 among columnar / OLAP databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.