Thank you, Fabian. Any chance you might have an example on how to define a data flow with Flink?
On Mon, Feb 15, 2016 at 3:58 PM, Fabian Hueske <fhue...@gmail.com> wrote: > It is not possible to "pin" data sets in memory, yet. > However, you can stream the same data set through two different mappers at > the same time. > > For instance you can have a job like: > > /---> Map 1 --> SInk1 > Source --< > \---> Map 2 --> SInk2 > > and execute it at once. > For that you define you data flow and call execute once after all sinks > have been created. > > Best, Fabian > > 2016-02-15 21:32 GMT+01:00 Saliya Ekanayake <esal...@gmail.com>: > >> Fabian, >> >> count() was just an example. What I would like to do is say run two map >> operations on the dataset (ds). Each map will have it's own reduction, so >> is there a way to avoid creating two jobs for such scenario? >> >> The reason is, reading these binary matrices are expensive. In our >> current MPI implementation, I am using memory maps for faster loading and >> reuse. >> >> Thank you, >> Saliya >> >> On Mon, Feb 15, 2016 at 3:15 PM, Fabian Hueske <fhue...@gmail.com> wrote: >> >>> Hi, >>> >>> it looks like you are executing two distinct Flink jobs. >>> DataSet.count() triggers the execution of a new job. If you have an >>> execute() call in your program, this will lead to two Flink jobs being >>> executed. >>> It is not possible to share state among these jobs. >>> >>> Maybe you should add a custom count implementation (using a >>> ReduceFunction) which is executed in the same program as the other >>> ReduceFunction. >>> >>> Best, Fabian >>> >>> >>> >>> 2016-02-15 21:05 GMT+01:00 Saliya Ekanayake <esal...@gmail.com>: >>> >>>> Hi, >>>> >>>> I see that an InputFormat's open() and nextRecord() methods get called >>>> for each terminal operation on a given dataset using that particular >>>> InputFormat. Is it possible to avoid this - possibly using some caching >>>> technique in Flink? >>>> >>>> For example, I've some code like below and I see for both the last two >>>> statements (reduce() and count()) the above methods in the input format get >>>> called. Btw. this is a custom input format I wrote to represent a binary >>>> matrix stored as Short values. >>>> >>>> ShortMatrixInputFormat smif = new ShortMatrixInputFormat(); >>>> >>>> DataSet<Short[]> ds = env.createInput(smif, >>>> BasicArrayTypeInfo.SHORT_ARRAY_TYPE_INFO); >>>> >>>> MapOperator<Short[], DoubleStatistics> op = ds.map(...) >>>> >>>> *op.reduce(...)* >>>> >>>> *op.count(...)* >>>> >>>> >>>> Thank you, >>>> Saliya >>>> -- >>>> Saliya Ekanayake >>>> Ph.D. Candidate | Research Assistant >>>> School of Informatics and Computing | Digital Science Center >>>> Indiana University, Bloomington >>>> Cell 812-391-4914 >>>> http://saliya.org >>>> >>> >>> >> >> >> -- >> Saliya Ekanayake >> Ph.D. Candidate | Research Assistant >> School of Informatics and Computing | Digital Science Center >> Indiana University, Bloomington >> Cell 812-391-4914 >> http://saliya.org >> > > -- Saliya Ekanayake Ph.D. Candidate | Research Assistant School of Informatics and Computing | Digital Science Center Indiana University, Bloomington Cell 812-391-4914 http://saliya.org
