Global Windows is fine for this use case. I have used the same strategy. You just define custom evictors and triggers and you are all good. Windows are managed by keys, so as such as long as events are evicted from the window, that counts towards reclaiming memory for the key+window combination. Plus there is just window per key with Global Windows.
On Wed, Apr 24, 2019 at 7:47 AM M Singh <mans2si...@yahoo.com> wrote: > Hi Rong: > > Thanks for your answer. > > From what I understand the dynamic gap session windows are also created > when the event is encountered. I need to be able to change the window end > time at a later time based on what other events are in that window. One > way to do this is to use GlobalWindows but then these are never deleted. > > Regarding CEP option - I believe that CEP patterns cannot be changed > dynamically once they've been complied which limits it usage. > > Please feel free to correct me. > > Thanks for your help and pointers. > > On Tuesday, April 23, 2019, 8:12:56 PM EDT, Rong Rong <walter...@gmail.com> > wrote: > > > Hi Mans, > > I am not sure what you meant by "dynamically change the end-time of a > window. If you are referring to dynamically determines the firing time of > the window, then it fits into the description of session window [1]: > If you want to handle window end time dynamically, one way of which I can > think of is the dynamic gap, session window [1] approach. with which you > can specify the end-time of a window based on input elements. Provided that > you are maintaining a session window. > Another way to look at it is through the Flink-CEP library [2]. > > Thanks, > Rong > > > [1] > https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/stream/operators/windows.html#session-windows > [2] > https://ci.apache.org/projects/flink/flink-docs-release-1.8/dev/libs/cep.html#groups-of-patterns > > On Tue, Apr 23, 2019 at 8:19 AM M Singh <mans2si...@yahoo.com> wrote: > > Hi: > > I am working on a project and need to change the end time of the window > dynamically. I want to find out if the end time of the window is used > internally (for sorting windows/etc) except for handling watermarks that > would cause problems if the end time was changed during run time after the > window has been created even if no new event has arrived for that window. > > I don't want to use GlobalWindow since from my understanding it never gets > destroyed. > > If there is any alternate way of dealing with this, please let me know. > > Thanks > > Mans > >
