Hi everybody, as already stated, I try currently to implement a Machine Learning algorithm on Stratosphere for the ML group at TU Berlin. I ran into some issues.
The basic scheme of my algorithm is: X = input data Y = input data residuals = Y model = array[float, float, float] size n
for i in 1:n a = calc_a(X, residuals) b = calc_b(X, a, residuals) c = calc_c(X, a, b, c, residuals) model(i) = (a, b, c) residuals = update_residuals(residuals, a, b, c)
output model My attempt now would be to use the delta iterations, use the model as solution set, and the residuals as working sets: Code: -------------------------------------------------------------------------------------------------------------------------------------------------------
val X = getInputSource
val Y = DataSource(YFile, CsvInputFormat[Float]) val model = CollectionDataSource[(Int, Float, Float, Float)](List()) val residual = Y def step_function(model: DataSet[(Int, Float, Float, Float)], residuals: DataSet[Float]) = { import util.Random (CollectionDataSource(Seq(new Tuple4(Random.nextInt, 1.0f, 1.0f, 2.0f))), residuals) } model.iterateWithDelta( residual, { x: (Int, Float, Float, Float) => x._1 }, step_function, config.iterations ) val output = model //map { x => println(x); x } val sink = output.write(outFile, CsvOutputFormat[(Int, Float, Float, Float)], "Model output") Code End ---------------------------------------------------------------------------------------------------------------------------------------------------- At the moment I try just to output a list of tuples.
My problems are: - instead of the random integer I would like to insert the index of the iterations. - I get this error: 08/12/2014 20:14:37: Job execution switched to status SCHEDULED 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) (1/1) switched to SCHEDULED 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to SCHEDULED 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) (1/1) switched to ASSIGNED 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to ASSIGNED 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) (1/1) switched to READY 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) (1/1) switched to STARTING 08/12/2014 20:14:37: Job execution switched to status RUNNING 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) (1/1) switched to RUNNING 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to READY 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to STARTING 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to RUNNING 08/12/2014 20:14:38: DataSource(<Unnamed Collection Data Source>) (1/1) switched to FINISHING 08/12/2014 20:14:38: DataSource(<Unnamed Collection Data Source>) (1/1) switched to CANCELING 08/12/2014 20:14:38: DataSink(Model output) (1/1) switched to FAILED java.lang.RuntimeException: Cannot serialize record with out field at position: 0 at eu.stratosphere.api.java.record.io.CsvOutputFormat.writeRecord(CsvOutputFormat.java:295) at eu.stratosphere.api.java.record.io.CsvOutputFormat.writeRecord(CsvOutputFormat.java:50) at eu.stratosphere.pact.runtime.task.DataSinkTask.invoke(DataSinkTask.java:178) at eu.stratosphere.nephele.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:284) at java.lang.Thread.run(Thread.java:744) I doubt there is no record inside model. Because if I enable the map function in the second last line I get an IndexOutOfBounds exception at index 0.
Many thanks in adavance Cheers, Max |
Hi, right now, the only way of updating the solution set in a delta iteration is by joining with the solution set from the previous iteration and having the result of that join as the result of the step function. I working on simplifying iterations as well as bringing the Scala API to feature parity with the Java API. It should not be possible right now to create a new data source inside each iteration step.The way to get at the current iteration number is by having a rich function instead of a lambda function. So instead of: val otherSet = someSet map( new MapFunction[InType, OutType]() { } }) I hope that helps. Aljoscha On Tue, Aug 12, 2014 at 8:21 PM, Maximilian Alber <[hidden email]> wrote:
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Hi! Thank you! But how do I join my result to the solution set if I cannot create a new DataSet inside the iteration? In Scala there is not yet a RichFunction for the Iterations, am I right? So I should best use the Java class?
Mit freundlichen Grüßen,
Max! On Fri, Aug 15, 2014 at 3:50 PM, Aljoscha Krettek <[hidden email]> wrote:
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Hi, there is no RichFunction in the Java API either. You don't have to create a new DataSet. Your iteration result will be a DataSet that results from some operations based on the previous SolutionSet and/or WorkingSet. For example:} On Sun, Aug 17, 2014 at 6:14 PM, Maximilian Alber <[hidden email]> wrote:
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RichFunctions were added to the JavaAPI recently: https://github.com/apache/incubator-flink/tree/72d7b86274c33d1570ffb22b1fca2081c15d753c/flink-java/src/main/java/org/apache/flink/api/java/functions 2014-08-18 8:16 GMT+02:00 Aljoscha Krettek <[hidden email]>:
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Yes, but they were always available. Because user code in Java was always in "Rich Functions". There is no rich function for iterations, though, since iterations themselves don't have user code attached. Aljoscha On Mon, Aug 18, 2014 at 10:59 AM, Fabian Hueske <[hidden email]> wrote:
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Ok. I'm back at this point: In the 0.7 version is there a way to get the superstep number inside a iterateWithDeta function? Cheers, Max On Mon, Aug 18, 2014 at 12:05 PM, Aljoscha Krettek <[hidden email]> wrote:
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Hi, yes you can, I modified the ConnectedComponents Example to print out the iteration number inside one of the Join functions: // open a delta iteration val verticesWithComponents = vertices.iterateDelta(vertices, maxIterations, Array(0)) { (s, ws) => // apply the step logic: join with the edges val allNeighbors = ws.join(edges).where(0).equalTo(0) ( new RichJoinFunction[(Long, Long), (Long, Long), (Long, Long)] { override def join(vertex: (Long, Long), edge: (Long, Long)): (Long, Long) = { val context = getIterationRuntimeContext println("Iteration #" + context.getSuperstepNumber) (edge._2, vertex._2) } }) // select the minimum neighbor val minNeighbors = allNeighbors.groupBy(0).min(1) // update if the component of the candidate is smaller val updatedComponents = minNeighbors.join(s).where(0).equalTo(0) { (newVertex, oldVertex, out: Collector[(Long, Long)]) => if (newVertex._2 < oldVertex._2) out.collect(newVertex) } // delta and new workset are identical (updatedComponents, updatedComponents) } Unfortunately for this you have to use a RichFunction instead of a lambda. Cheers, Aljoscha On Sat, Sep 27, 2014 at 11:09 AM, Maximilian Alber <[hidden email]> wrote:
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Ah ok, that's the trick. So I can just use inside dataset function applied via rich functions during the iteration but not in the "first level" iteration code? But it shouldn't be a problem for me. Thanks! Cheers, Max On Mon, Sep 29, 2014 at 9:51 AM, Aljoscha Krettek <[hidden email]> wrote:
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Yes, the "first level" iteration code is actually not executed at
runtime. It is only executed once to put together the DataSet operations. This graph of operations is then repeatedly executed at runtime. Cheers, Aljoscha On Mon, Sep 29, 2014 at 10:30 AM, Maximilian Alber <[hidden email]> wrote: > Ah ok, that's the trick. So I can just use inside dataset function applied > via rich functions during the iteration but not in the "first level" > iteration code? > But it shouldn't be a problem for me. > > Thanks! > Cheers, > Max > > On Mon, Sep 29, 2014 at 9:51 AM, Aljoscha Krettek <[hidden email]> > wrote: >> >> Hi, >> yes you can, I modified the ConnectedComponents Example to print out the >> iteration number inside one of the Join functions: >> >> // open a delta iteration >> val verticesWithComponents = vertices.iterateDelta(vertices, >> maxIterations, Array(0)) { >> (s, ws) => >> >> // apply the step logic: join with the edges >> val allNeighbors = ws.join(edges).where(0).equalTo(0) ( >> new RichJoinFunction[(Long, Long), (Long, Long), (Long, Long)] { >> override def join(vertex: (Long, Long), edge: (Long, Long)): >> (Long, Long) = { >> val context = getIterationRuntimeContext >> println("Iteration #" + context.getSuperstepNumber) >> (edge._2, vertex._2) >> >> } >> }) >> >> // select the minimum neighbor >> val minNeighbors = allNeighbors.groupBy(0).min(1) >> >> // update if the component of the candidate is smaller >> val updatedComponents = minNeighbors.join(s).where(0).equalTo(0) { >> (newVertex, oldVertex, out: Collector[(Long, Long)]) => >> if (newVertex._2 < oldVertex._2) out.collect(newVertex) >> } >> >> // delta and new workset are identical >> (updatedComponents, updatedComponents) >> } >> >> Unfortunately for this you have to use a RichFunction instead of a lambda. >> >> Cheers, >> Aljoscha >> >> On Sat, Sep 27, 2014 at 11:09 AM, Maximilian Alber >> <[hidden email]> wrote: >>> >>> Ok. I'm back at this point: >>> >>> In the 0.7 version is there a way to get the superstep number inside a >>> iterateWithDeta function? >>> >>> Cheers, >>> Max >>> >>> On Mon, Aug 18, 2014 at 12:05 PM, Aljoscha Krettek <[hidden email]> >>> wrote: >>>> >>>> Yes, but they were always available. Because user code in Java was >>>> always in "Rich Functions". There is no rich function for iterations, >>>> though, since iterations themselves don't have user code attached. >>>> >>>> Aljoscha >>>> >>>> >>>> On Mon, Aug 18, 2014 at 10:59 AM, Fabian Hueske <[hidden email]> >>>> wrote: >>>>> >>>>> RichFunctions were added to the JavaAPI recently: >>>>> >>>>> >>>>> https://github.com/apache/incubator-flink/tree/72d7b86274c33d1570ffb22b1fca2081c15d753c/flink-java/src/main/java/org/apache/flink/api/java/functions >>>>> >>>>> Cheers, Fabian >>>>> >>>>> >>>>> 2014-08-18 8:16 GMT+02:00 Aljoscha Krettek <[hidden email]>: >>>>> >>>>>> Hi, >>>>>> there is no RichFunction in the Java API either. You don't have to >>>>>> create a new DataSet. Your iteration result will be a DataSet that results >>>>>> from some operations based on the previous SolutionSet and/or WorkingSet. >>>>>> For example: >>>>>> >>>>>> def stepFunction(s: DataSet[SolutionType], ws: DataSet[WorksetType]) = >>>>>> { >>>>>> val intermediate = ws.join(somethingFromOutside) where {...} >>>>>> isEqualTo {...} map {...} >>>>>> val newSolution = s.join(intermediate) where ... >>>>>> val newWorkset = ... >>>>>> (newSolution, newWorkset) >>>>>> } >>>>>> >>>>>> Aljoscha >>>>>> >>>>>> >>>>>> On Sun, Aug 17, 2014 at 6:14 PM, Maximilian Alber >>>>>> <[hidden email]> wrote: >>>>>>> >>>>>>> Hi! >>>>>>> Thank you! >>>>>>> >>>>>>> But how do I join my result to the solution set if I cannot create a >>>>>>> new DataSet inside the iteration? >>>>>>> In Scala there is not yet a RichFunction for the Iterations, am I >>>>>>> right? So I should best use the Java class? >>>>>>> >>>>>>> Mit freundlichen Grüßen, >>>>>>> Max! >>>>>>> >>>>>>> >>>>>>> On Fri, Aug 15, 2014 at 3:50 PM, Aljoscha Krettek >>>>>>> <[hidden email]> wrote: >>>>>>>> >>>>>>>> Hi, >>>>>>>> right now, the only way of updating the solution set in a delta >>>>>>>> iteration is by joining with the solution set from the previous iteration >>>>>>>> and having the result of that join as the result of the step function. I >>>>>>>> working on simplifying iterations as well as bringing the Scala API to >>>>>>>> feature parity with the Java API. It should not be possible right now to >>>>>>>> create a new data source inside each iteration step. >>>>>>>> >>>>>>>> The way to get at the current iteration number is by having a rich >>>>>>>> function instead of a lambda function. So instead of: >>>>>>>> val someSet = ... >>>>>>>> val otherSet = someSet map { x => x + 1} >>>>>>>> >>>>>>>> you would have: >>>>>>>> val someSet = ... >>>>>>>> val otherSet = someSet map( new MapFunction[InType, OutType]() { >>>>>>>> def apply(in: SomeType): SomeOtherType = { >>>>>>>> val iteration = >>>>>>>> getIterationRuntimeContext().getSuperstepNumber() >>>>>>>> (iteration, x, y, ...) >>>>>>>> } >>>>>>>> }) >>>>>>>> >>>>>>>> I hope that helps. >>>>>>>> >>>>>>>> Aljoscha >>>>>>>> >>>>>>>> >>>>>>>> On Tue, Aug 12, 2014 at 8:21 PM, Maximilian Alber >>>>>>>> <[hidden email]> wrote: >>>>>>>>> >>>>>>>>> Hi everybody, >>>>>>>>> >>>>>>>>> as already stated, I try currently to implement a Machine Learning >>>>>>>>> algorithm on Stratosphere for the ML group at TU Berlin. I ran into some >>>>>>>>> issues. >>>>>>>>> >>>>>>>>> The basic scheme of my algorithm is: >>>>>>>>> >>>>>>>>> X = input data >>>>>>>>> Y = input data >>>>>>>>> residuals = Y >>>>>>>>> >>>>>>>>> model = array[float, float, float] size n >>>>>>>>> >>>>>>>>> for i in 1:n >>>>>>>>> a = calc_a(X, residuals) >>>>>>>>> b = calc_b(X, a, residuals) >>>>>>>>> c = calc_c(X, a, b, c, residuals) >>>>>>>>> >>>>>>>>> model(i) = (a, b, c) >>>>>>>>> residuals = update_residuals(residuals, a, b, c) >>>>>>>>> >>>>>>>>> output model >>>>>>>>> >>>>>>>>> My attempt now would be to use the delta iterations, use the model >>>>>>>>> as solution set, and the residuals as working sets: >>>>>>>>> >>>>>>>>> Code: >>>>>>>>> ------------------------------------------------------------------------------------------------------------------------------------------------------- >>>>>>>>> val X = getInputSource >>>>>>>>> val Y = DataSource(YFile, CsvInputFormat[Float]) >>>>>>>>> >>>>>>>>> val model = CollectionDataSource[(Int, Float, Float, >>>>>>>>> Float)](List()) >>>>>>>>> val residual = Y >>>>>>>>> >>>>>>>>> def step_function(model: DataSet[(Int, Float, Float, Float)], >>>>>>>>> residuals: DataSet[Float]) = { >>>>>>>>> import util.Random >>>>>>>>> (CollectionDataSource(Seq(new Tuple4(Random.nextInt, 1.0f, 1.0f, >>>>>>>>> 2.0f))), residuals) >>>>>>>>> } >>>>>>>>> >>>>>>>>> model.iterateWithDelta( >>>>>>>>> residual, >>>>>>>>> { x: (Int, Float, Float, Float) => x._1 }, >>>>>>>>> step_function, >>>>>>>>> config.iterations >>>>>>>>> ) >>>>>>>>> >>>>>>>>> val output = model //map { x => println(x); x } >>>>>>>>> val sink = output.write(outFile, CsvOutputFormat[(Int, Float, >>>>>>>>> Float, Float)], "Model output") >>>>>>>>> >>>>>>>>> Code End >>>>>>>>> ---------------------------------------------------------------------------------------------------------------------------------------------------- >>>>>>>>> >>>>>>>>> At the moment I try just to output a list of tuples. >>>>>>>>> >>>>>>>>> My problems are: >>>>>>>>> - instead of the random integer I would like to insert the index of >>>>>>>>> the iterations. >>>>>>>>> - I get this error: >>>>>>>>> 08/12/2014 20:14:37: Job execution switched to status SCHEDULED >>>>>>>>> 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to SCHEDULED >>>>>>>>> 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to >>>>>>>>> SCHEDULED >>>>>>>>> 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to ASSIGNED >>>>>>>>> 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to >>>>>>>>> ASSIGNED >>>>>>>>> 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to READY >>>>>>>>> 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to STARTING >>>>>>>>> 08/12/2014 20:14:37: Job execution switched to status RUNNING >>>>>>>>> 08/12/2014 20:14:37: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to RUNNING >>>>>>>>> 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to READY >>>>>>>>> 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to >>>>>>>>> STARTING >>>>>>>>> 08/12/2014 20:14:37: DataSink(Model output) (1/1) switched to >>>>>>>>> RUNNING >>>>>>>>> 08/12/2014 20:14:38: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to FINISHING >>>>>>>>> 08/12/2014 20:14:38: DataSource(<Unnamed Collection Data Source>) >>>>>>>>> (1/1) switched to CANCELING >>>>>>>>> 08/12/2014 20:14:38: DataSink(Model output) (1/1) switched to >>>>>>>>> FAILED >>>>>>>>> java.lang.RuntimeException: Cannot serialize record with out field >>>>>>>>> at position: 0 >>>>>>>>> at >>>>>>>>> eu.stratosphere.api.java.record.io.CsvOutputFormat.writeRecord(CsvOutputFormat.java:295) >>>>>>>>> at >>>>>>>>> eu.stratosphere.api.java.record.io.CsvOutputFormat.writeRecord(CsvOutputFormat.java:50) >>>>>>>>> at >>>>>>>>> eu.stratosphere.pact.runtime.task.DataSinkTask.invoke(DataSinkTask.java:178) >>>>>>>>> at >>>>>>>>> eu.stratosphere.nephele.execution.RuntimeEnvironment.run(RuntimeEnvironment.java:284) >>>>>>>>> at java.lang.Thread.run(Thread.java:744) >>>>>>>>> >>>>>>>>> I doubt there is no record inside model. Because if I enable the >>>>>>>>> map function in the second last line I get an IndexOutOfBounds exception at >>>>>>>>> index 0. >>>>>>>>> >>>>>>>>> Many thanks in adavance >>>>>>>>> >>>>>>>>> Cheers, >>>>>>>>> Max >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >>> >> > |
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