In http://hg.mozilla.org/build/puppet-manifests/rev/e651fe658196 we changed to using the x86_64 versions of the nagios daemon in our puppet configs. Because they had previously been installed with the i386 packages, and those i386 packages weren't ever removed, we have been running our nagios from the non-puppet managed i386 nagios-plugins packages ever since. A couple options exist to fix this: 1) use the 32-bit plugins on 64bit linux 2) have a different nrpe.cfg for 64bit linux 3) convert nrpe.cfg into a template I think we should fix the immediate problem by having a different nrpe.cfg for 64-bit linux slaves. Looking at our VMs, they should have the correct plugins and nagios requirements already installed to work with the different configs so nothing should break. I have attached a diff that should work with the puppet-deployed version of nagios.

this is fixing it for me