On Sat, Mar 24, 2018 at 8:38 AM, Matteo Merli <mme...@apache.org> wrote:
> While profiling the allocations of a BookKeeper client (from current > master) writing entries, I've noticed that there are multiple allocations > per entry related to the OrderedScheduler. > > I think OrderedScheduler was introduced in 4.6 and now OrderedSafeExecutor > is just an extension of OrderedScheduler as well. > OrderedSafeExecutor extends OrderedScheduler was for BC. We made common util classes in bookkeeper-common. > > The main problem is that since OrderedScheduler supports both immediate and > delayed execution, it uses a ScheduledThreadPoolExecutor per each bucket, > plus some decorating wrappers. > Sound like this is the solution: - Keep the OrderedScheduler - Copy the OrderedScheduler to OrderedExecutor and change it to the original executor implementation - Let OrderedSafeScheduler extends OrderedExecutor (bc purpose) > > The ScheduledThreadPoolExecutor, needs a Priority queue and also always > return future objects. > > From my memory snapshot I have counted 12 objects allocated (per addEntry > operation) for a total of 472 bytes per each entry, all due the scheduled > executor. > > I think the delayed execution is only used in unit tests. In critical paths > we're only using the immediate task submission. > > I think it might be worth to refactor OrderedScheduler or > OrderedSafeExecutor to avoid that overhead. > > Thoughts? > > Matteo > -- > Matteo Merli > <mme...@apache.org> >
