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What's New in NSClient++ 0.4.2

The main goal of the 0.4.2 update is to create a new modern check subsystem.

This means all checks will get:

  • help command line options to get help
  • proper documentation
  • the same or similar syntax
  • "real-time" options in many instances


Completely new documentation tool chain (your reading the result).

New windows subsystem

The windows subsystem in < 0.4.2 is optimized for Windows NT and really needs an overhaul.

  • Support for remote checking of windows machines (i.e. allow NSClient++ act as a broker and check remote machines in an agent-less fashion)
  • Support for Modern Windows (vista and beyond)
  • Drop support for "Legacy Windows" (will still be available as-is in but not updated/get extended support)
  • Support real-time monitoring in more instances

New Syntax

All queries has inherited the new syntax from "event-log checks" this means you can now check a lot of nifty stuff which was previously impossible. It also makes things much simpler as all the command now has the same syntax where previously most command has slight different dialects.

A simple example of migrating a command:

CheckCPU MaxWarn=80% MaxCrit=90%
check_cpu "warn=load > 80%" "crit=load > 90%"

The first thing to realize is that the old commands still work as they will be migrated automatically for you. Also all new commands have _ instead of CamelCase of check_cpu is the new version of CheckCPU.

Migrating the thresholds is pretty simple as well as most old thresholds are of the form Max/Min crit this or that. and then you just replace them as above.

Sensible defaults

Another change is that all new commands now have a sensible default. For instance check_cpu will work without arguments.