THIS IS A TEST INSTANCE. ALL YOUR CHANGES WILL BE LOST!!!!
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package org.apache.flink.ml.iteration; /** * A helper class that contains the streams returned by the iteration body. */ class IterationBodyResult { /** * A list of feedback variable streams. These streams will only be used during the iteration execution and will * not be returned to the caller of the iteration body. It is assumed that the method which executes the * iteration body will feed the records of the feedback variable streams back to the corresponding input variable * streams. */ DataStreamList feedbackVariableStreams; /** * A list of output streams. These streams will be returned to the caller of the methods that execute the * iteration body. */ DataStreamList outputStreams; /** * An optional termination criteria stream. If this stream is not null, it will be used together with the * feedback variable streams to determine when the iteration should terminate. */ Optional<DataStream<@Nullable DataStream<?>>> terminationCriteria; } |
3) Add the IterationListener interface.
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package org.apache.flink.ml.iteration; import org.apache.flink.annotation.Experimental; import org.apache.flink.iteration.operator.allround.AllRoundOperatorWrapper; /** * A helper class to create applyiterations. {@linkTo IterationBody}construct toan data streams. */ @PublicEvolving public class IterationUtils { /*iteration, Users are required to provide * * <ul> * * This<li>initVariableStreams: methodthe caninitial usevalues anof iterationthe bodyvariable todata processstreams recordswhich inwould unboundedbe data streams. updated * * in each round. * This method invokes <li>dataStreams: the other data streams used inside the iteration body with the following parameters: * 1) The 1st, but would not be updated. * <li>iterationBody: specifies the subgraph to update the variable streams and the outputs. * </ul> * * <p>The iteration body will be invoked with two parameters: The first parameter is a list of input * variable streams, which are created as the union of the initial variable * streams and the * corresponding feedback variable streams (returned by the iteration body). * 2); The 2ndsecond parameter is * the data streams given to this method. * * <p>During the execution of iteration body, each of * The epoch values are determined as described below. See IterationListener for how the epoch values are used. * 1) Allthe records involved in the iteration has an * epoch attached, which is mark the progress of the iteration. The epoch is computed as: * * <ul> * <li>All records in the initial variable streams and initial data streams has epoch =1 0. * <li>For * 2) All records in the data streams has epoch=MAX_LONG. In this case, records in the data stream won't affect * any operator's epoch watermark. * 3) For any record emitted by this operator into a non-feedback stream, the epoch of thisany record emitted by this operator into a non-feedback stream, the epoch of this * emitted record = the * epoch of the input record that triggers this emission. If this record * is emitted by is emitted *by onEpochWatermarkIncremented(), then the epoch of this record = epochWatermark. * epochWatermark. * 4) For<li>For any record emitted by this operator into a feedback variable stream, the epoch of the * emitted record = emitted *record = min(the epoch of the input record that triggers this emission, MAX_LONG - 1) + 1. If this record is emitted by * onEpochWatermarkIncremented(), then the epoch of this record = epochWatermark + 1. * * The execution of the graph created by* </ul> * * <p>The framework would given the notification at the end of each epoch for operators and UDFs * that implements {@link IterationListener}. * * <p>The limitation of constructing the subgraph inside the iteration body could be willrefer notin terminate{@link by* itselfIterationBody}. This* is* because<p>An atexample least of the iteration is like: * one of its data streams is unbounded. * * Required: * 1) All the init variable streams must be bounded. * 2) There is at least one unbounded stream in the data streams list. * 3) The parallelism of any stream in the initial variable streams must equal the parallelism of the stream at the * same index of the feedback variable streams returned by the IterationBody. * * @param initVariableStreams The initial variable streams. These streams will be merged with the feedback variable * streams before being used as the 1st parameter to invoke the iteration body. * @param dataStreams The data streams. These streams will be used as the 2nd parameter to invoke the iteration * body. * @param body The computation logic which takes variable/data streams and returns variable/output streams. * @return The list of output streams returned by the iteration boy. */ static DataStreamList iterateUnboundedStreams(DataStreamList initVariableStreams, DataStreamList dataStreams, IterationBody body) {...} /** * This method can use an iteration body to process records in some bounded data streams iteratively until a * termination criteria is reached (e.g. the given number of rounds is completed or no further variable update is * needed). Because this method does not replay records in the data streams, the iteration body needs to cache those * records in order to visit those records repeatedly. * * This method invokes the iteration body with the following parameters: * 1) The 1st parameter is a list of input variable streams, which are created as the union of the initial variable * streams and the corresponding feedback variable streams (returned by the iteration body). * 2) The 2nd parameter is the data streams given to this method. * * The epoch values are determined as described below. See IterationListener for how the epoch values are used. * 1) All records in the initial variable streams has epoch=1. * 2) All records in the data streams has epoch=1. * 3) For any record emitted by this operator into a non-feedback stream, the epoch of this emitted record = the * epoch of the input record that triggers this emission. If this record is emitted by * onEpochWatermarkIncremented(), then the epoch of this record = epochWatermark. * 4) For any record emitted by this operator into a feedback variable stream, the epoch of the emitted record = the * epoch of the input record that triggers this emission + 1. If this record is emitted by * onEpochWatermarkIncremented(), then the epoch of this record = epochWatermark + 1. * * Suppose there is a coordinator operator which takes all feedback variable streams (emitted by the iteration body) * and the termination criteria stream (if not null) as inputs. The execution of the graph created by the * iteration body will terminate when all input streams have been fully consumed AND any of the following conditions * is met: * 1) The termination criteria stream is not null. And the coordinator operator has not observed any new value from * the termination criteria stream between two consecutive onEpochWatermarkIncremented invocations. * 2) The coordinator operator has not observed any new value from any feedback variable stream between two * consecutive onEpochWatermarkIncremented invocations. * * Required: * 1) All the init variable streams and the data streams must be bounded. * 2) The parallelism of any stream in the initial variable streams must equal the parallelism of the stream at the * same index of the feedback variable streams returned by the IterationBody. * * @param initVariableStreams The initial variable streams. These streams will be merged with the feedback variable * streams before being used as the 1st parameter to invoke the iteration body. * @param dataStreams The data streams. These streams will be used as the 2nd parameter to invoke the iteration * body. * @param body The computation logic which takes variable/data streams and returns variable/output streams. * @return The list of output streams returned by the iteration boy. */ static DataStreamList iterateBoundedStreamsUntilTermination(DataStreamList initVariableStreams, DataStreamList dataStreams, IterationBody body) {...} /** * This method can use an iteration body to process records in some bounded data streams iteratively until a * termination criteria is reached (e.g. the given number of rounds is completed or no further variable update is * needed). Because this method replays records in the data streams, the iteration body does not need to cache those * records to visit those records repeatedly. * * This method invokes the iteration body with the following parameters: * 1) The 1st parameter is a list of input variable streams, which are created as the union of the initial variable * streams and the corresponding feedback variable streams (returned by the iteration body). * 2) The 2nd parameter is a list of replayed data streams, which are created by replaying the initial data streams * round by round until the iteration terminates. The records in the Nth round will be emitted into the iteration * body only if the low watermark of the first operator in the iteration body >= N - 1. * * The epoch values are determined as described below. See IterationListener for how the epoch values are used. * 1) All records in the initial variable streams has epoch=1. * 2) The records from the initial data streams will be replayed round by round into the iteration body. The records * in the first round have epoch=1. And records in the Nth round have epoch = N* <pre>{@code * DataStreamList result = Iterations.iterateUnboundedStreams( * DataStreamList.of(first, second), * DataStreamList.of(third), * (variableStreams, dataStreams) -> { * ... * return new IterationBodyResult( * DataStreamList.of(firstFeedback, secondFeedback), * DataStreamList.of(output)); * } * result.<Integer>get(0).addSink(...); * }</pre> */ @Experimental public class Iterations { /** * This method uses an iteration body to process records in unbounded data streams. The * iteration would not terminate if at least one of its inputs is unbounded. Otherwise it will * terminated after all the inputs are terminated and no more records are iterating. * * @param initVariableStreams The initial variable streams, which is merged with the feedback * variable streams before being used as the 1st parameter to invoke the iteration body. * @param dataStreams The non-variable streams also refered in the {@code body}. * 3)@param For any record emitted by this operator into a non-feedback stream, the epoch of this emitted record = thebody The computation logic which takes variable/data streams and returns * epoch of the input record that triggers this emission. If this record is emitted by * onEpochWatermarkIncremented(), then the epoch of this record = epochWatermark. * 4) For any record emitted by this operator into a feedback stream, the epoch of the emitted record = the epochfeedback/output streams. * @return The list of output streams returned by the iteration boy. */ public static DataStreamList iterateUnboundedStreams( DataStreamList initVariableStreams, DataStreamList dataStreams, IterationBody body){} /** * This ofmethod theuses inputan recorditeration thatbody triggersto thisprocess emissionrecords +in 1.some Ifbounded thisdata recordstreams is emitted by onEpochWatermarkIncremented(), * iteratively until a *termination thencriteria theis epoch of this record = epochWatermark + 1.reached (e.g. the given number of rounds is * completed or no further *variable Supposeupdate there is aneeded). coordinatorBecause operatorthis whichmethod takesdoes allnot feedbackreplay variable streams (emitted by the* iterationrecords body) in the data streams, the *iteration andbody theneeds terminationto criteriacache streamthose (ifrecords notin null)order asto inputs. The execution of the* graphvisit createdthose byrecords therepeatedly. * iteration body will terminate when* all@param inputinitVariableStreams streamsThe haveinitial beenvariable fullystreams, consumedwhich ANDis anymerged ofwith the following conditionsfeedback * is met: variable streams before being used *as 1)the The1st terminationparameter criteriato streaminvoke isthe notiteration null. And the coordinator operator has not observed any new value frombody. * @param dataStreams The non-variable streams also refered in the {@code body}. * @param body theThe terminationcomputation criterialogic streamwhich betweentakes twovariable/data consecutivestreams onEpochWatermarkIncrementedand invocations.returns * 2) The coordinator operator has not observed any new value from any feedback variable stream between two * consecutive onEpochWatermarkIncremented invocationsfeedback/output streams. * @return The list of output streams returned by the iteration boy. */ public * Required:static DataStreamList iterateBoundedStreamsUntilTermination( * 1) All the init variable streams andDataStreamList theinitVariableStreams, dataDataStreamList streamsdataStreams, mustIterationBody be bounded.body) {} /** 2) The parallelism of any* streamThis inmethod thecan initialuse variablean streamsiteration mustbody equalto theprocess parallelismrecords ofin thesome streambounded atdata thestreams * sameiteratively indexuntil ofa thetermination feedbackcriteria variableis streams returned byreached (e.g. the IterationBody. given number of rounds *is * @paramcompleted initVariableStreamsor Theno initialfurther variable streams.update Theseis streamsneeded). willBecause bethis mergedmethod withreplays therecords feedback variablein * the data streams, the iteration body does not need to cache those records to visit those * records repeatedly. This corresponds streamsto beforethe beingbulk usediteration asin the 1stdataset. parameter to invoke the iteration body.* * @param initDataStreamsinitVariableStreams The initial datavariable streams., Recordswhich fromis thesemerged streamswith willthe befeedback repeatedly replayed and used * * variable streams before being used as the 1st parameter to invoke the iteration body. * @param dataStreams The non-variable asstreams thealso 2ndrefered parameterin to invoke the iteration{@code body}. * @param body The computation logic which takes variable/data streams and returns variable * feedback/output streams. * @return The list of output streams returned by the iteration boy. */ public static DataStreamList iterateAndReplayBoundedStreamsUntilTermination(bulkIterateAndReplayBoundedStreamsUntilTermination( DataStreamList initVariableStreams, DataStreamList initDataStreamsdataStreams, IterationBody body) {...} } |
5) Add the DataStreamList class.
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