21. 12. 2012 Michael Medin NetEye

NSClient++ 0.4.1 released!

NSClient++ founder Michael Medin

NSClient++ has for many years been the de facto way to monitor Windows machines from Nagios derived monitoring solutions such as Neteye, which over the past years has integrated various additional functionalities in its offer. With the new version (0.4.1) we are now moving steadily from “just a windows agent” to become versatile tool to help you simplify your monitoring by adding protocol independence platform independence as well as modern monitoring paradigms such as state full scripting and real-time monitoring. This post will go through many of the major changes from the previous stable version (0.3.9) and while it is not intended as a hands on tutorial or an upgrade guide it will hopefully give you a good idea about the new features introduced. A tutorial for how to upgrade will be posted soon so please stay tuned for that.

The core
The main change in 0.4.1 (and 0.4.0 as well) is that much of the internals have been replaced with standard libraries meanings things should work much better. It also means things are a lot more extensible and customizable meaning this is the most power-full NSClient++ yet. Another new change is the configuration which introduces a new hierarchal ini-format as registry support. To help with managing the configuration the new version has extensive command line support for validating, generating, migrating and documenting the configuration.
Lastly the new version boost a much improved command line syntax making it a joy to work with NSClient++ from the command line as well as Linux support.
All in all 0.4.0 was the biggest change ever in the history of NSClient++.

An interesting side effect of the new core is platform independence meaning you can now use NSClient++ on Linux (and while not all modules are supported more are added in each new version) I also start to incorporate real-time checks starting with event log monitoring. Last but not least over 10.000 unit test was added to help improve code quality and reduce the number of regression issues. Just a final reminder the configuration file format has changed but the old (nsc.ini) is still supported and more importantly you can easily migrate to the new (nsclient.ini) format. Please note that while you can use both and migrate between them they are not compatible as both keys and section names have changed their names.

Checks
In the check department we have a lot of new features. in general the shift towards real-time monitoring is continuing as well as the focus to modernize and provide plattform independence for checks. The first brand new platform independent module is ChecklogFile which provides similar features as CheckEventLog for checking text (log) files. This module has a new improved syntax over CheckEventlog which will be added to CheckEventlog (and many other modiules as well) if deemed a good interface. To seamlessly integrate real-time monitoring in “active” (aka NRPE) style setups we have provided another new module called SimpleCache which can be used to stor real-time results for checking via for instance NRPE.
The combination with the cache and the two log file checks provides a way to efficiently process massive file with millions of lines without impacting system performance. In addition to this we also introduce the SimpleFileWriter module whch can direkt the results to a file similar to what NSCA server does on Linux. This means in theory NSCLient++ could now replace NSCA server component. In addition to this there is there usual myrriad of bug fixes and enhancments. The most notable enchantment is the performance counters which are now
working (again) on various localized windows. Also don’t forget to lookinto the varoous commad line helpers such as “nscp sys” and “nscp eventlog” and “nscp wmi” for helping you diagnose and configure checks as well as even provide unit testing for your monitoring enviornment.

Extensibility
One of the major features in this category is the new Python script support as well as Lua support. The scripts are running inside NSClient++ which means you have access to all parts of NSClient++ as well as full support for state. In addition to this we have full dot-net support as well as a new sample plugin.

Protocols
A lot of new protocols were added bringin the supported list to NRPE, NSCA, NRDP, NSClient (check_nt), SysLog, SMTP, Graphite, check_mk. In addition to this another big focus was improving quality as well as add real security in the form of FULL ssl support including certificate based authentication. Other notable fixes and enchantments include full ipv6 support as well as retry handling to better cater for network issues as well as prop-per timeout handling.

Command line syntax
This has been a big focus are and the new command line syntax improvments makes this the first time I can say that it is a joy to work with the command line I have almost entirely tarted to use the command line for configuration changes for instance. We have also introdiuced a myrriad of wys to work with your settings file including vlidating, generating and even removing all default values (good to cleanout your config file). hopefully this will help resolve your configuration issues. The most important thing to understand avout the new configuration syntax is the use of the double dash (–) which can be a bit confusing to the cashual observer but in essence it is pretty straight forward everthing after the double dashes are sent to the module anything before “will be interceptetd if understood by NSClient++”. est way to illustrate this is comparing “nscp nrpe –help” with “nscp nrpe —
–help” where the first will give you information about how to configutre logging and loading settings file and what not where as the latter gives you the NRPE options such as host port command and arguments.

Bulding and writing plugins
Building NSClient++ is now a breeze on both Linux and Windows due to some nifty helper scripts (I am looking at you fetchdeps.py) and there is a fully fledged (not really) sample plugin if you want to try out writing custom plugins. I have also fixed almost all -Wall warning on gcc so should look nice when you compile now. I also have for internal use setup on-commit builds in Ubuntu, debian and centos so seems we are well underway to have a stable Linux enviornment. I am still lookig for insight into how better turn NSCLient++ into a nice option on the Linux side as well.