Dan, The part about classes being stored in a database has me confused. I thought that classes were in-memory for each run of a component (cf-agent, cf-serverd, etc.). Are you saying classes are something like a shared value between the components, rather than each component essentially having its own view of the world, so to speak?
I assume you're referring to cf_classes.tcdb. Can you elaborate a bit more on how that file is used? The reference manual says the file is a "database of classes that have been defined on the current host, including their relative frequences, scaled like a probability". That sounds to me like it's statistical/historical, rather than realtime, information. Thanks, Justin -----Original Message----- From: d...@lonewolf.com [mailto:d...@lonewolf.com] On Behalf Of daniel.kl...@cfengine.com Sent: Wednesday, April 21, 2010 4:08 PM To: Lebel, Marco Cc: Justin Lloyd; fo...@cfengine.com; help-cfengine@cfengine.org Subject: Re: Cfengine Help: Re: RE: Cfengine Help: cfengine program flow Kinda-sorta :-) Classes that are defined in a "common" bundle are global. Classes that are defined in any other kind of bundle are local to that bundle. See section 1.6 of the manual. Likewise, classes are cached with an expiration time, but they do go away. Although they can be set with a test, the condition which sets them is not continuously evaluated - so they stick around a bit. Classes are stored in a database - so that the various components of Cfengine can share them. You can clear a class with the -U switch, if you need to. -Dan > Justin, > > You are bringing an interesting point since I struggle with classes in this c > ontext. But I have not done any structured testing but I am under the impres > sion that once a class has been set it never gets unset. > > Again I want to stress that I never did any exhaustive testing on this but I > believe that classes once set they are set globally (i.e. visible in all subs > equent bundle) and never get unset even if the condition that initially creat > ed it is no longer true... Again the key word is an impression that needs to > be confirmed by someone in the know or has done the necessary testing. > > Marco > > -----Original Message----- > From: help-cfengine-boun...@cfengine.org [mailto:help-cfengine-boun...@cfengi > ne.org] On Behalf Of Justin Lloyd > Sent: Wednesday, April 21, 2010 5:31 PM > To: fo...@cfengine.com; help-cfengine@cfengine.org > Subject: RE: Cfengine Help: Re: RE: Cfengine Help: cfengine program flow > > As I understand it, it will reevalute the class promise, and therefore > check for the file's existence, on all three iterations. A good way to > see what is happening is to run cf-agent in verbose mode (cf-agent -vK) > and write its output to a file then read through it. You'll see lines > like this (yours will be prefixed with something other than "nova>"): > > [r...@rhn ~]# cf-agent -vK > /tmp/out > [r...@rhn ~]# grep '^nova>.* in bundle .* ([1-3])' /tmp/out > nova> vars in bundle def (1) > nova> classes in bundle def (1) > nova> vars in bundle def (2) > nova> classes in bundle def (2) > nova> vars in bundle def (3) > nova> classes in bundle def (3) > nova> vars in bundle update (1) > nova> classes in bundle update (1) > nova> processes in bundle update (1) > nova> commands in bundle update (1) > nova> files in bundle update (1) > nova> services in bundle update (1) > nova> vars in bundle update (2) > nova> classes in bundle update (2) > nova> processes in bundle update (2) > nova> commands in bundle update (2) > nova> files in bundle update (2) > nova> services in bundle update (2) > nova> vars in bundle update (3) > nova> classes in bundle update (3) > nova> processes in bundle update (3) > nova> commands in bundle update (3) > nova> files in bundle update (3) > nova> services in bundle update (3) > nova> vars in bundle dg (1) > nova> classes in bundle dg (1) > nova> vars in bundle dg (2) > nova> classes in bundle dg (2) > nova> vars in bundle dg (3) > nova> classes in bundle dg (3) > > Note how it does 3 iterations of the promise types in bundle "def", then > 3 of bundle "update", etc. ("dg" is a custom bundle of mine). > > Justin > > -----Original Message----- > From: help-cfengine-boun...@cfengine.org > [mailto:help-cfengine-boun...@cfengine.org] On Behalf Of > fo...@cfengine.com > Sent: Wednesday, April 21, 2010 3:22 PM > To: help-cfengine@cfengine.org > Subject: Cfengine Help: Re: RE: Cfengine Help: cfengine program flow > > Forum: Cfengine Help > Subject: Re: RE: Cfengine Help: cfengine program flow > Author: nicolas > Link to topic: > https://cfengine.com/forum/read.php?3,16959,16960#msg-16960 > > thanks for the fast response. > it helps, i thought this is a recommendation :-/ (i should read more > exactly) > > but one question i still have: > > if i define a class: > > classes: > > "xy_installed" expression => fileexists("/usr/example"); > > does it recheck this value each time i use > > xy_installed:: > > or only once at the beginning of each of the 3 times? > > regards > > nicolas > > _______________________________________________ > Help-cfengine mailing list > Help-cfengine@cfengine.org > https://cfengine.org/mailman/listinfo/help-cfengine > > This electronic communication and any attachments may contain confidential an > d proprietary > information of DigitalGlobe, Inc. 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