head to head · open source
Vector vs client_java
Vector has 22,793 GitHub stars, 2,371 forks, 2,512 open issues and last shipped yesterday. client_java has 2,291 stars, 837 forks, 23 open issues and last shipped yesterday. Vector leads on adoption by 895% (22,793 vs 2,291 stars). Vector is written in Rust under MPL-2.0; client_java is written in Java under Apache-2.0. Vector has attracted 10% as many forks as stars, client_java 37%. client_java was the more recently maintained of the two, and both are self-hostable with no licence fee. The two share 1 topic tag (metrics), so they are genuine substitutes rather than adjacent tools.
Two open source projects, one decision. Both are free and self-hostable — the differences are community size, license terms, language stack and release pace.
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Side by side
| Vector | client_java | |
|---|---|---|
| GitHub stars | ★ 23K | ★ 2.3K |
| License | MPL-2.0 | Apache-2.0 |
| Written in | Rust | Java |
| Last push | 2026-11-04 | 2026-11-04 |
| Forks | ⑂ 2.4K | ⑂ 837 |
| Self-hosting | Yes | Yes |
| Data ownership | Your server | Your server |
pick Vector if
- You weight community size — 23K stars and counting
- You want the MPL-2.0 license terms
- Your stack matches Rust
- You value the larger contributor base for long-term maintenance
pick client_java if
- You want the client_java feature set and don't need the biggest community
- You prefer the Apache-2.0 license terms
- Your stack matches Java
- You evaluated both and client_java fits your workflow better
About Vector
Quickstart • Docs • Guides • Integrations • Chat • Download • Container Images • Rust Crate Docs What is Vector? Vector is a high performance, end to end (agent & aggregator) observability data pipeline that puts you in control of your observability data. [Collect][docs.sources], [transform][docs.transforms], and [route][docs.sinks] all your logs and metrics to any vendors you want today and any other vendors you may want tomorrow. Vector enables dramatic cost reduction, novel data enrichment, and data security where you need it, not where it is most convenient for your…
read the full Vector overview →
About client_java
Prometheus Java Metrics Library [![Build][build badge]][build workflow] [build badge]: [build workflow]: Documentation Contributing and community See CONTRIBUTING.md and the community section of the Prometheus homepage. The Prometheus Java community is present on the CNCF Slack on prometheus java , and we have a fortnightly community call in the Prometheus public calendar. Previous Releases The source code for 0.16.0 and older is on the simpleclient branch. License Apache License 2.0, see LICENSE.
read the full client_java overview →
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Frequently asked questions
Is Vector or client_java more popular?
Vector has 22,793 GitHub stars and client_java has 2,291. Vector has the larger community by that measure.
Are Vector and client_java free?
Both are open source. Vector is licensed under MPL-2.0 and client_java under Apache-2.0. Neither carries a licence fee.
What is the difference between Vector and client_java?
Vector is written in Rust and client_java in Java. The practical differences are community size, licence terms, language stack and release cadence — all compared in the table above.
Which should I choose, Vector or client_java?
Choose Vector if you want the larger community (22,793 stars) or its MPL-2.0 licence terms. Choose client_java if its feature set, stack or Apache-2.0 licence fits better. Both are self-hostable.