mtail vs OpenSearch
A side-by-side comparison of two self-hosted monitoring & status options — licensing, setup difficulty, resource needs, and what each one replaces.
OpenSearch
Search and observability suite with logs and dashboards
| Feature | mtail | OpenSearch |
|---|---|---|
| Deploy effort | Under-an-hour setup | Under-an-hour setup |
| Health score | 54 · Fair | 94 · Excellent |
| Category | Monitoring & Status | Monitoring & Status |
| License | Apache-2.0 | Apache-2.0 |
| Language | Go | Java |
| Setup difficulty | Medium | Hard |
| Min. RAM | 64 MB | 2,048 MB |
| Deployment | docker, binary, kubernetes | docker, kubernetes, helm |
| GitHub stars | ★ 4,032 | ★ 13,765 |
| First released | 2015 | 2021 |
| Replaces | Splunk, Datadog Log Metrics | Elasticsearch, Splunk |
What are mtail and OpenSearch?
mtail
mtail is a tool from Google for extracting metrics from application logs to be exported into a time series database. It runs small programs that parse log lines and increment counters or gauges, bridging log data into Prometheus monitoring.
- Turns log lines into metrics
- Compact pattern language
- Prometheus export endpoint
- Low overhead tailing
OpenSearch
OpenSearch is a community-driven search, analytics, and observability suite forked from Elasticsearch and Kibana. OpenSearch Dashboards provides log exploration, visualizations, and alerting for operational data.
- Full-text and log search
- Observability dashboards
- Anomaly detection
- Alerting plugin
mtail vs OpenSearch: key differences
Mtail is written in Go, while OpenSearch is built with Java. Mtail is the lighter option, starting around 64 MB of RAM against 2,048 MB for OpenSearch. Mtail is the more established project (first released 2015), while OpenSearch arrived in 2021. OpenSearch has the considerably larger community, at 13,765 GitHub stars versus 4,032.
Why pick each one
Choose mtail if…
- Bridges legacy logs to metrics
- Tiny footprint
Watch out for
- Custom program language to learn
- Not a full log pipeline
Choose OpenSearch if…
- Truly open-source license
- Rich analytics features
Watch out for
- Resource heavy
- Cluster tuning required
Frequently asked questions
Is mtail or OpenSearch better?
Neither is universally better. OpenSearch has the larger community, while mtail is simpler to set up (medium difficulty). Choose based on the comparison table above and your own setup.
Are mtail and OpenSearch free and open-source?
Yes. mtail is licensed under Apache-2.0 and OpenSearch under Apache-2.0. Both can be self-hosted at no software cost.
Can I run mtail and OpenSearch with Docker?
mtail: yes. OpenSearch: yes.
Which is lighter on resources, mtail or OpenSearch?
mtail has the smaller minimum footprint at 64 MB of RAM, compared to about 2,048 MB for OpenSearch. Real-world usage depends on library size, user count, and enabled features.