Version 3.0.0-rc1 Released

Lorenz Kästle, December 3, 2025

The Monitoring Plugins Development Team announces version 3.0.0-rc1 of the Monitoring Plugins! This release is different in several regards to previous releases. Due the a significant refactoring and the unintented side effect this may have, the "real" release will be following release candidates which are intented to for early adapters and testing.

The core parts of this release are significant changes to the C part of this project, which should be mostly internal and not change the results in a significant way (meaning the input parameters mostly stay as they are and the exit code should remain the same if the parameters are the same in the old version and context did not change). The reality is, that big changes have unintented consequences which are not covered in the test cases or some consequences were not in our scope at all. For the list of notable changes in this release, see below.

You can get the tarball from our download page.

General changes

In the C part of the project
Heavy refactoring to simplify and unify the code base
Introduction of a generalized output mechanism for most plugins
Standardized code formatting via clang-format

Specific changes

check_curl

check_curl received a lot of changes which improve the documentation and fix several bugs. It is also not considered experimental anymore.

Additionaly check_curl can now be configured to handle cookies internally without saving cookies to the filesystem.

check_http

check_http is now considered deprecated and will not receive attention any more. It is replaced by check_curl

check_snmp

check_snmp does not execute snmpget or snmpgetnext anymore but executes the net-snmp calls natively now.

check_nwstat

check_nwstat was removed, due to its perceived insignificance in the current IT world. This reduces the maintenance load and ressource consumption in general.

check_by_ssh

check_by_ssh ignores output on stderr by default now. This should avoid false positives for warnings by the OpenSSH client (especially about the server missing Post-Quantum cryptography.

check_dns

check_dns now ignores CNAMES in reverse DNS mode.

check_fping

If during compilation fping 5.2, 5.3 or higher are present, check_fping will be able to use new options which were introduced with these versions. These options are (equivalent to the ones with the same name in fping) --fwmark, --icmp-timestamp and --check-source. The older flags --dontfrag and --random were also added.

Also the -4 and -6 flags may not have worked as intented and should be fixed now.

check_mysql

check_mysql should now be able to correctly detect whether a replica is attached and working correctly. Changes were necessary here to adapt to changes in the naming convention in MySQL.