FiloDB
FiloDB is a free, open-source distributed database for real-time time-series, event, and operational data, with Prometheus query support.
What FiloDB is
FiloDB is a free, open-source distributed database for real-time time-series, event, and operational data, with Prometheus query support. It is designed to ingest and query many millions of time series, distributing data across processes and supporting distributed queries. Columnar compression and off-heap memory management help keep substantial data in memory while reducing garbage collection. PromQL is available through an HTTP API and CLI, although the README describes support as about 60%. Histograms are a first-class column type; the project says this can improve compression and query speeds by up to two orders of magnitude. A typical real-time ingestion setup consumes Apache Kafka, while the Gateway accepts metrics over TCP using Influx Line Protocol. The README describes Grafana use through the Prometheus-compatible API and identifies Cassandra as its persistence store. FiloDB runs as standalone processes in a cluster. Building it requires Java, Cassandra, Kafka, Rust, a C compiler, and SBT. It is licensed under Apache-2.0.
Good
- Open-source and free under Apache-2.0
- Designed for many millions of time series
- Supports distributed querying and horizontal scaling
- PromQL available through HTTP API and CLI
Watch out
- PromQL support is described as about 60%
- Gateway is labeled experimental
- Build requires Java, Cassandra, Kafka, Rust, C compiler, and SBT
- Project lists OLAP and transactional workflows as anti-use-cases
Who it suits
FiloDB suits teams managing real-time operational metrics, distributed tracing, application-metric debugging, or event data. It is for teams prepared to run and build a self-managed cluster with its listed dependencies.
Verdict
FiloDB offers distributed, in-memory time-series storage with PromQL support and Kafka ingestion. Its build prerequisites and experimental Gateway make deployment scope and maturity important considerations.
Plans and prices
From FiloDB's own pricing page, checked 10 Oct 2026.
| Plan | Price | What it gives you |
|---|---|---|
| FiloDB | Free | Open-source database · Self-managed deployment |
The facts
Each one read from FiloDB's own pages, with the date it was checked.
What it does
- Deployment
- FiloDB is deployed as standalone processes in a cluster and requires Java, Cassandra, Kafka, Rust, and a C compiler to build; SBT is also listed as a build prerequisite.checked 10 Oct 2026
- Gateway
- The Gateway accepts metrics over TCP and currently supports Influx Line Protocol; its only tested setup uses Telegraf with a Prometheus endpoint source.checked 10 Oct 2026
- Histograms
- It stores histograms as a first-class column type and says this can improve compression and query speeds by up to two orders of magnitude.checked 10 Oct 2026
- Ingestion
- Its usual real-time ingestion setup consumes directly from Apache Kafka, with cluster processes coordinated using Akka Cluster.checked 10 Oct 2026
- Integrations
- The README describes using FiloDB as a Grafana data source through its Prometheus-compatible HTTP API and identifies Cassandra as its persistence store.checked 10 Oct 2026
- License
- The repository identifies Apache-2.0 as its license.checked 10 Oct 2026
- Maturity
- The README labels FiloDB Standalone stable and tested at scale, Gateway experimental, Cassandra and Kafka stable, and Spark deprecated.checked 10 Oct 2026
- Not for
- The project lists heavily transactional update-oriented workflows and OLAP or analytics as anti-use-cases.checked 10 Oct 2026
- Product
- FiloDB is an open-source distributed, real-time, in-memory time-series, event, and operational database with Prometheus query support.checked 10 Oct 2026
- Querying
- FiloDB supports PromQL through an HTTP API and CLI, and the README says its PromQL support is about 60%.checked 10 Oct 2026
- Scale
- It is designed to ingest and query many millions of time series, with data sharded across processes and distributed querying built in.checked 10 Oct 2026
- Storage
- Columnar compression and off-heap memory management help it store substantial data in memory while reducing garbage collection.checked 10 Oct 2026
- Support
- The repository invites contributions; it does not state a paid support plan on the README page.checked 10 Oct 2026
- Use cases
- Documented uses include operational metrics, distributed tracing storage, ad-hoc application-metric debugging, and real-time event storage and querying.checked 10 Oct 2026
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