On Thu, Feb 21, 2013 at 3:28 AM, Igor Stasenko <siguc...@gmail.com> wrote: > Hi. > > There is one thing which is IMO an over-engineering artifact: > - when system goes down (image shutdown), all currently scheduled > delays are "saved" > and then when image starting up they are rescheduled again to keep > waiting what time is left for delay..
Right now one says Delay forMilliseconds: n etc. That's clearly a duration. An API which said Delay until: aTime is different, and could be added to the current API easily. One good reason for keeping the current behaviour is profiling image shutdown and startup. The current MessageTally is slightly broken in this regard but I fixed it at Cadence to profile our start-up slowness. So please consider carefully throwing this behaviour away. I at least find it quite useful. > > But the problem is that it does not takes into account the total time > an image was frozen, and the requirement is quite ambiguous: > > - if you put a process on a delay for 5 minutes, then immediately > save image, and then restart it 10 minutes (or 1 year) after, > should this delay keep waiting for 4 +x seconds which is left? Or > should we consider this delay as utterly expired? > (and as you can see, the answer is different, if we counting time > using real, physical time, or just image uptime). > > And why counting image uptime? Consider use cases, like connection > timeout.. it is all about > real time , right here , right now.. will it matter to get socket > connection timeout error when you restart some image 1 year after? > Please, give me a scenario, which will illustrate that we cannot live > without it and should count image uptime for delays, because i can't > find one. > > If not, then to my opinion, and to simplify all logic inside delay > code, i would go straight and declare following: > - when new image session starts, all delays, no matter for how long > they are scheduled to wait are considered expired (and therefore all > waiting processes > is automatically resumed). > > Because as tried to demonstrate, the meaning of delay which spans over > multiple image sessions is really fuzzy and i would be really > surprised to find a code > which relies on such behavior. > > This change will also can be helpful with terminating all processes > which were put on wait for too long (6304550344559763 milliseconds) by > mistake or such. > > > -- > Best regards, > Igor Stasenko. > -- best, Eliot
