Thanks for posting these discoveries you are making - I'm just starting to work with cfengine and this stuff is very useful to know.
________________________________________ From: help-cfengine-boun...@cfengine.org [help-cfengine-boun...@cfengine.org] On Behalf Of Justin Lloyd [jll...@digitalglobe.com] Sent: Wednesday, March 10, 2010 1:46 PM To: help-cfengine@cfengine.org Subject: Defining classes using "dist" This is just an FYI post, so feel free to ignore my rambling if you're not interested in some slightly deeper mechanics. :) So, I've learned something this morning. As I recall from reading, Cfengine iterates its agent ordering (vars, classes, etc.) up to three times. A close examination of verbose agent output shows this in lines like "files in bundle dg (1)", etc. In further diagnosing an issue I'm having, I noticed that the dist_percent class I created is evaluated during each such ordering iteration, rather than once for each invocation of cf-agent as I had originally thought. Thus, my promise that is conditional based upon the existence of dist_percent_1 might be evaluated during the second iteration, where dist_percent_1 might be true for any or none of the three iterations of a given cf-agent invocation. So rather than my original statement that cf-agent runs 288 times per day (12 times per hour * 24 hours), the dist promise happens up to three times as often, meaning the number of times dist_percent_1 being defined is not 1% of 288 but 1% of 288*3, or 2.8*3 = 8-9 times per day. However, since the specific class promise I want evaluated only happens during one of the three ordering iterations, the chances of percent_dist_1 occurring during the iteration when the desired promise would be evaluated would be 1/3rd of the total percent, bringing it back down to the original 2-3 times per day. I only discuss this since it is good to understand the actual mechanics of what is happening with dist promises. On a related note, I had another question in my mind answered by verbose output during my testing: nova> ========================================================= nova> classes in bundle asset (3) nova> ========================================================= nova> nova> nova> + Private classes augmented: nova> + dist_percent_99 nova> + dist_percent nova> + dist_percent_1 nova> + fetched_asset_data nova> + dg_runtime_gold As you can see, dist classes are NOT mutually exclusive, as the _1 and _99 classes are both defined at the same time during this particular iteration of the asset bundle. I wasn't sure from the documentation whether this was the case, but this confirms it. The documentation does state, however, that the base dist_percent class would always be defined. Justin -----Original Message----- From: help-cfengine-boun...@cfengine.org [mailto:help-cfengine-boun...@cfengine.org] On Behalf Of Justin Lloyd Sent: Wednesday, March 10, 2010 10:02 AM To: nwat...@symcor.com Cc: help-cfengine@cfengine.org; help-cfengine-boun...@cfengine.org Subject: RE: Evaluating a promise occasionally Now that I re-read the splayclass description in the morning when I'm fresh and not in the evening when I'm worn out, I actually understand it. For this specific case, however, it appears slightly too limited, since I want the class defined 2-3 times per day. Splayclass can only take "hourly" or "daily" as its second argument. At least now I know I can use it for other stuff in the future now that I understand it. :) Thanks, Justin -----Original Message----- From: nwat...@symcor.com [mailto:nwat...@symcor.com] Sent: Wednesday, March 10, 2010 9:58 AM To: Justin Lloyd Cc: help-cfengine@cfengine.org; help-cfengine-boun...@cfengine.org Subject: RE: Evaluating a promise occasionally Splayclass? Sincerely, -- Neil Watson 416-673-3465 This electronic communication and any attachments may contain confidential and proprietary information of DigitalGlobe, Inc. If you are not the intended recipient, or an agent or employee responsible for delivering this communication to the intended recipient, or if you have received this communication in error, please do not print, copy, retransmit, disseminate or otherwise use the information. Please indicate to the sender that you have received this communication in error, and delete the copy you received. DigitalGlobe reserves the right to monitor any electronic communication sent or received by its employees, agents or representatives. _______________________________________________ Help-cfengine mailing list Help-cfengine@cfengine.org https://cfengine.org/mailman/listinfo/help-cfengine _______________________________________________ Help-cfengine mailing list Help-cfengine@cfengine.org https://cfengine.org/mailman/listinfo/help-cfengine _______________________________________________ Help-cfengine mailing list Help-cfengine@cfengine.org https://cfengine.org/mailman/listinfo/help-cfengine
