rsyslog
Rsyslog is a high-performance, modular log ingestion and processing engine written in C, capable of handling over one million messages per second. It supports multiple input sources (syslog, Kafka, MongoDB) and output destinations, with advanced routing and transformation capabilities. Licensed under LGPL-3.0, it is actively maintained and widely deployed in production environments.
Key facts
Objective fields from the source. Values we can't verify are shown as “Unknown” rather than guessed.
| Field | Value |
|---|---|
| Repository | rsyslog/rsyslog |
| Owner | rsyslog |
| Primary language | C |
| License | LGPL-3.0 — OSI-approved |
| Stars | 2.3k |
| Forks | 726 |
| Open issues | 239 |
| Latest release | v8.2606.0 (2026-06-25) |
| Last updated | 2026-07-08 |
| Source | https://github.com/rsyslog/rsyslog |
What rsyslog is
Rsyslog is a C-based syslog daemon evolved into a general-purpose log processing pipeline with a microkernel-like architecture. It offers modular input/output plugins, supports external scripts (Python, Perl), and integrates with Elasticsearch, Kafka, and MongoDB. Latest release v8.2606.0 (June 2026) with active development on master branch.
Get the rsyslog source
Clone the repository and explore it locally.
git clone https://github.com/rsyslog/rsyslog.gitcd rsyslog# follow the project's README for install & configurationNeed it deployed, integrated, or customized instead? DEV.co ships production installs.
Best use cases
Implementation considerations
- LGPL-3.0 license: derivative works and binary distributions must disclose source changes and provide licensing notices. Linked libraries must be LGPL-compatible or dual-licensed. Internal-only use has fewer restrictions; review legal requirements before production distribution.
- Performance tuning required for target throughput (buffering, batch sizes, output module selection). Default configuration may not achieve stated 1M msg/sec; profile against your workload.
- Plugin ecosystem split between built-in modules and external scripts (Python, Perl); external plugins require runtime dependencies and add operational surface area.
- Build dependencies (pkg-config, libestr, liblogging) must be available in your target environment; building from master may lag packaging in some distributions.
- Active maintenance with recent release (June 2026) and regular commits; however, 239 open issues suggest potential feature requests or bug backlogs to review.
When to avoid it — and what to weigh
- Minimal Logging Requirements — If your infrastructure requires only basic local logging or light forwarding, rsyslog's advanced features and operational overhead may be unnecessary; simpler alternatives exist.
- Real-Time Analytics or Machine Learning Requirements — Rsyslog is a log pipeline, not an analytics engine. It cannot perform statistical analysis, anomaly detection, or train ML models; you need a separate analytics platform downstream.
- Strict Proprietary or Restrictive Commercial License Requirement — LGPL-3.0 requires linking and modification disclosures. If your legal team prohibits copyleft licenses or requires proprietary licensing without source disclosure, rsyslog is not suitable.
- Zero System Administration Overhead — Rsyslog deployment, configuration tuning, and troubleshooting require operational expertise; it is not a 'set and forget' managed service.
License & commercial use
Rsyslog is licensed under LGPL-3.0 (GNU Lesser General Public License v3.0). This is a copyleft license that permits commercial use, modification, and distribution with conditions: source code must be disclosed for derived works, linking must be compatible (or dynamically linked), and licensing notices must be retained. Internal use without distribution has fewer obligations.
LGPL-3.0 permits commercial use, but requires careful handling: if you distribute rsyslog or a derivative (binary or modified source), you must provide source access, respect copyleft obligations, and ensure linked libraries are LGPL-compatible or dual-licensed. Consult legal counsel before distributing modified versions or bundled distributions. Internal/non-distributed use is less restricted. The project is sponsored by Adiscon (commercial vendor of related products), which suggests commercial viability.
DEV.co evaluation signals
Editorial assessment — not user reviews. Directional, with an explicit confidence level.
| Signal | Assessment |
|---|---|
| Maintenance | Active |
| Documentation | Adequate |
| License clarity | Clear |
| Deployment complexity | Moderate |
| DEV.co fit | Good |
| Assessment confidence | High |
LGPL-3.0 code is open-source and subject to community security review. No independent security audit, penetration test results, or formal security disclosure policy mentioned in provided data. Rsyslog handles sensitive log data (potentially PII, credentials, system state); deployment should enforce TLS, authentication, RBAC, and access controls. No known recent CVE details provided. Evaluate threat model against your log data classification and network position. Plugin ecosystem (especially external scripts) increases attack surface; audit third-party plugins before use.
Alternatives to consider
Filebeat / Logstash (Elastic Stack)
Filebeat is lighter-weight for log collection; Logstash offers more transformation features and native Elasticsearch integration. Proprietary licensing or Elastic License applies; may have higher operational overhead but stronger observability ecosystem.
Fluentd / Fluent Bit
Fluent Bit is lighter and more cloud-native; Fluentd offers plugin ecosystem similar to rsyslog. Both under permissive licenses (Apache 2.0 / BSD). Better container/Kubernetes integration out-of-box; less mature on legacy syslog compatibility.
Vector
Modern, Rust-based log router with strong performance, observability, and cloud-native design. MPL-2.0 license (permissive). Fewer legacy syslog integrations but superior Kubernetes and cloud integrations; less battle-tested in traditional datacenter deployments.
Build on rsyslog with DEV.co software developers
Rsyslog offers proven performance for high-volume log aggregation and transformation. Let our engineering team help you assess licensing, integration, and operational fit for your architecture. Contact us to discuss deployment strategy.
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rsyslog FAQ
Can I use rsyslog commercially?
What is rsyslog's typical throughput, and how do I achieve it?
How stable is rsyslog for production?
Does rsyslog provide analytics or real-time dashboards?
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Ready to Evaluate Rsyslog for Your Logging Infrastructure?
Rsyslog offers proven performance for high-volume log aggregation and transformation. Let our engineering team help you assess licensing, integration, and operational fit for your architecture. Contact us to discuss deployment strategy.