Hey Neil, I concur that using duplicate task IDs is bad practice and asking for trouble.
Could you please clarify *why* you want to use a hashmap? Is your goal to remove duplicate task IDs or is this just a side-effect and you have a different reason (e.g. performance) for using a hashmap? I'm wondering why a multi-hashmap is not sufficient. This would be clear if you were explicitly *trying* to get rid of duplicates of course :-) Thanks, Joris — *Joris Van Remoortere* Mesosphere On Fri, Dec 9, 2016 at 7:08 AM, Neil Conway <neil.con...@gmail.com> wrote: > Folks, > > The master stores a cache of metadata about recently completed tasks; > for example, this information can be accessed via the "/tasks" HTTP > endpoint or the "GET_TASKS" call in the new Operator API. > > The master currently stores this metadata using a list; this means > that duplicate task IDs are permitted. We're considering [1] changing > this to use a hashmap instead. Using a hashmap would mean that > duplicate task IDs would be discarded: if two completed tasks have the > same task ID, only the metadata for the most recently completed task > would be retained by the master. > > If this behavior change would cause problems for your framework or > other software that relies on Mesos, please let me know. > > (Note that if you do have two completed tasks with the same ID, you'd > need an unambiguous way to tell them apart. As a recommendation, I > would strongly encourage framework authors to never reuse task IDs.) > > Neil > > [1] https://reviews.apache.org/r/54179/ >
