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KairosDB

maintenance

by KairosDB community · since 2013

Java time-series database layered on Cassandra or ScyllaDB, from the OpenTSDB lineage.

time-seriesdatabase engineopen source (permissive)legacy
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maintenance. Sporadic maintenance: last stable release 1.3.0 (Aug 2021); 1.4.0-beta.1 tagged Jan 2026.

Overview

KairosDB began in 2013 as a rewrite of OpenTSDB that swapped HBase for Cassandra, keeping the metric-plus-tags model and the telnet and HTTP put APIs while adding a richer JSON query API with aggregators, groupers and rollups. Running on Cassandra or ScyllaDB gives it straightforward horizontal scale and multi-datacenter replication through the underlying store. Development is sporadic: the last stable release, 1.3.0, came out in 2021, and a 1.4.0 beta was tagged in early 2026. It is mainly relevant where a Cassandra cluster already exists and teams want a thin metrics layer on top.

Time-series dataObservability

Strengths & trade-offs

Strengths

  • +Reuses an existing Cassandra or ScyllaDB cluster for storage
  • +Stateless front ends and multi-DC replication via the backing store
  • +JSON query API with aggregators, groupers and rollups
  • +Accepts OpenTSDB-style writes

Trade-offs

  • −Little active development; last stable release 2021
  • −No PromQL or SQL
  • −Requires operating Cassandra, which is heavy for metrics alone
  • −Small and shrinking community

Great for

  • +Metrics on an existing Cassandra deployment
  • +Legacy OpenTSDB migrations off HBase

Think twice for

  • −New Kubernetes monitoring stacks
  • −Teams without Cassandra expertise
  • −SQL analytics

Capabilities

Native or official first-party support · 3 of 25 tracked

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

Scale & consistency

Comfortable data size
Large · ≤ 1 PB
Horizontal scaling
Native
Multi-region
Active active
Transactions
None
Consistency
Tunable
Schema
Schemaless
Architecture
Distributed, Client server
Query languages
KairosDB JSON query API

Scales and replicates through the backing Cassandra or ScyllaDB cluster; KairosDB nodes are stateless.

Deployment

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

Ecosystem

compatible withCassandra (CQL), OpenTSDB
apis & protocolsHTTP REST, Telnet put protocol, Graphite plaintext (plugin)
client languagesJava

Alternatives to KairosDB

Compare all→
OpenTSDBTime-Series6.9

HBase-backed time-series database from the Hadoop era; still in service, rarely chosen for new work.

kairosdb vs opentsdb →
VictoriaMetricsTime-Series26.8

Resource-frugal, Prometheus-compatible metrics database, run as a single binary or a sharded cluster.

kairosdb vs victoriametrics →
Apache CassandraWide-Column55.9

Masterless wide-column database built for always-on writes across data centers.

kairosdb vs apache-cassandra →
ScyllaDBWide-Column45.9

C++ rewrite of Cassandra with shard-per-core design; also speaks the DynamoDB API.

kairosdb vs scylladb →
InfluxDBTime-Series51.0

Purpose-built time-series database, rebuilt in Rust on Arrow, DataFusion and Parquet for version 3.

kairosdb vs influxdb →
M3DBTime-Series4.2

Uber-born distributed TSDB and aggregator for Prometheus-scale metrics with tunable replication.

kairosdb vs m3db →

KairosDB FAQ

What is KairosDB?

KairosDB is a time-series database by KairosDB community, first released in 2013. KairosDB began in 2013 as a rewrite of OpenTSDB that swapped HBase for Cassandra, keeping the metric-plus-tags model and the telnet and HTTP put APIs while adding a richer JSON query API with aggregators, groupers and rollups. Running on Cassandra or ScyllaDB gives it straightforward horizontal scale and multi-datacenter replication through the underlying store. Development is sporadic: the last stable release, 1.3.0, came out in 2021, and a 1.4.0 beta was tagged in early 2026. It is mainly relevant where a Cassandra cluster already exists and teams want a thin metrics layer on top.

Is KairosDB open source?

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

Does KairosDB support ACID transactions?

No. KairosDB does not provide ACID transactions; its consistency model is tunable.

Does KairosDB scale horizontally?

KairosDB scales horizontally out of the box, with built-in sharding or partitioning. It is comfortable at large scale (≤ 1 PB). It supports active-active multi-region writes.

How can I run KairosDB?

You can self-host it.

What is KairosDB best for?

KairosDB is a strong fit for metrics on an existing Cassandra deployment and legacy OpenTSDB migrations off HBase. Think twice for new Kubernetes monitoring stacks.

What are the best alternatives to KairosDB?

Common alternatives to KairosDB include OpenTSDB, VictoriaMetrics, Apache Cassandra, ScyllaDB and InfluxDB. The right choice depends on your workload, scale and hosting; WhichDB's smart match ranks them against your requirements.

Is KairosDB still maintained?

KairosDB is in maintenance mode. Sporadic maintenance: last stable release 1.3.0 (Aug 2021); 1.4.0-beta.1 tagged Jan 2026.

How popular is KairosDB?

KairosDB ranks #376 of 844 databases on the WhichDB Score (5.7/100), and #24 among time-series databases. The score combines public adoption signals such as package downloads, GitHub activity, job posts and developer discussion.