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About NSClient++

NSClient++ (nscp) aims to be a simple yet powerful and flexible monitoring daemon. It was built for Nagios/Icinga/Naemon, but nothing in the daemon is specific to those systems, and it is used in many other scenarios where check metrics need to be collected, forwarded or acted upon. NSClient++ can also run standalone as the central monitoring system, though that is not recommended — the built-in scheduling and alerting are intentionally minimal compared to a dedicated monitoring server.

What does it do?

NSClient++ does three things:

  • Allow remote checks — let a monitoring server request commands on the monitored machine and return the result.
  • Monitor systems in real time — collect metrics locally and submit them to a remote monitoring server.
  • Resolve problems — act on its own findings or on instructions from a central server (for example restarting a service when a check fails).

In addition it offers a built-in Web UI, a REST API, and is scriptable in Lua and Python or via any external script.

What monitoring systems does it support?

NSClient++ was designed to work with Nagios/Naemon/Icinga but can easily be adapted to any monitoring or information system. The full module list lives in the reference; the protocols it speaks are:

Active checks (server side)

  • NRPE — Nagios Remote Plugin Executor
  • check_nt — legacy NSClient protocol
  • check_mk — Check_MK live status
  • REST / HTTP — NSClient++ native API

Passive submission (client side)

  • NSCA — Nagios Service Check Acceptor
  • NSCA-NG — TLS-based next-generation NSCA
  • NRDP — Nagios Remote Data Processor
  • Icinga 2 — passive results via the Icinga 2 REST API
  • Op5 — Op5 Monitor northbound API

Metrics and log forwarding

  • Graphite
  • Syslog
  • SMTP
  • CollectD
  • Elastic
  • Prometheus / OpenMetrics (scraped from the REST API)

Where does it run?

NSClient++ runs on Windows and most Linux distributions. There are two Windows editions — a standard build for Windows Server 2008 R2 / Windows 7 and later, and a legacy build that still runs on Windows XP. See Supported platforms for the full matrix.

Who is behind NSClient++?

NSClient++ is largely written and maintained by Michael Medin. He uses My Computer Solutions NORDIC KB as a company to handle the legal and financial aspects of the project.

Contacting the project can be done via email [email protected] or on the following address: 

Michael Medin
My Computer Solutions NORDIC KB
Knipvägen 179
SE-184 62 ÅKERSBERGA
SWEDEN