Java tutorial
/* * Licensed to the Apache Software Foundation (ASF) under one * or more contributor license agreements. See the NOTICE file * distributed with this work for additional information * regarding copyright ownership. The ASF licenses this file * to you under the Apache License, Version 2.0 (the * "License"); you may not use this file except in compliance * with the License. You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ package org.apache.flink.hdfstests; import org.apache.flink.api.common.ExecutionConfig; import org.apache.flink.api.common.io.FileInputFormat; import org.apache.flink.api.common.typeinfo.TypeInformation; import org.apache.flink.api.java.io.TextInputFormat; import org.apache.flink.api.java.tuple.Tuple2; import org.apache.flink.api.java.typeutils.TypeExtractor; import org.apache.flink.core.fs.FileInputSplit; import org.apache.flink.core.fs.Path; import org.apache.flink.core.testutils.OneShotLatch; import org.apache.flink.streaming.api.TimeCharacteristic; import org.apache.flink.streaming.api.functions.source.ContinuousFileMonitoringFunction; import org.apache.flink.streaming.api.functions.source.ContinuousFileReaderOperator; import org.apache.flink.streaming.api.functions.source.FileProcessingMode; import org.apache.flink.streaming.api.functions.source.SourceFunction; import org.apache.flink.streaming.api.functions.source.TimestampedFileInputSplit; import org.apache.flink.streaming.api.operators.StreamSource; import org.apache.flink.streaming.api.watermark.Watermark; import org.apache.flink.streaming.runtime.streamrecord.StreamRecord; import org.apache.flink.streaming.runtime.tasks.OperatorStateHandles; import org.apache.flink.streaming.util.AbstractStreamOperatorTestHarness; import org.apache.flink.streaming.util.OneInputStreamOperatorTestHarness; import org.apache.flink.streaming.util.OperatorSnapshotUtil; import org.apache.commons.io.FileUtils; import org.junit.Assert; import org.junit.ClassRule; import org.junit.Ignore; import org.junit.Test; import org.junit.rules.TemporaryFolder; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; /** * Tests that verify the migration from 1.2 snapshots. */ public class ContinuousFileProcessingFrom12MigrationTest { private static final int LINES_PER_FILE = 10; private static final long INTERVAL = 100; @ClassRule public static TemporaryFolder tempFolder = new TemporaryFolder(); /** * Manually run this to write binary snapshot data. Remove @Ignore to run. */ @Ignore @Test public void writeReaderSnapshot() throws Exception { File testFolder = tempFolder.newFolder(); TimestampedFileInputSplit split1 = new TimestampedFileInputSplit(0, 3, new Path("test/test1"), 0, 100, null); TimestampedFileInputSplit split2 = new TimestampedFileInputSplit(10, 2, new Path("test/test2"), 101, 200, null); TimestampedFileInputSplit split3 = new TimestampedFileInputSplit(10, 1, new Path("test/test2"), 0, 100, null); TimestampedFileInputSplit split4 = new TimestampedFileInputSplit(11, 0, new Path("test/test3"), 0, 100, null); // this always blocks to ensure that the reader doesn't to any actual processing so that // we keep the state for the four splits final OneShotLatch blockingLatch = new OneShotLatch(); BlockingFileInputFormat format = new BlockingFileInputFormat(blockingLatch, new Path(testFolder.getAbsolutePath())); TypeInformation<FileInputSplit> typeInfo = TypeExtractor.getInputFormatTypes(format); ContinuousFileReaderOperator<FileInputSplit> initReader = new ContinuousFileReaderOperator<>(format); initReader.setOutputType(typeInfo, new ExecutionConfig()); OneInputStreamOperatorTestHarness<TimestampedFileInputSplit, FileInputSplit> testHarness = new OneInputStreamOperatorTestHarness<>( initReader); testHarness.setTimeCharacteristic(TimeCharacteristic.EventTime); testHarness.open(); // create some state in the reader testHarness.processElement(new StreamRecord<>(split1)); testHarness.processElement(new StreamRecord<>(split2)); testHarness.processElement(new StreamRecord<>(split3)); testHarness.processElement(new StreamRecord<>(split4)); // take a snapshot of the operator's state. This will be used // to initialize another reader and compare the results of the // two operators. final OperatorStateHandles snapshot; synchronized (testHarness.getCheckpointLock()) { snapshot = testHarness.snapshot(0L, 0L); } OperatorSnapshotUtil.writeStateHandle(snapshot, "src/test/resources/reader-migration-test-flink1.2-snapshot"); } @Test public void testReaderRestore() throws Exception { File testFolder = tempFolder.newFolder(); final OneShotLatch latch = new OneShotLatch(); BlockingFileInputFormat format = new BlockingFileInputFormat(latch, new Path(testFolder.getAbsolutePath())); TypeInformation<FileInputSplit> typeInfo = TypeExtractor.getInputFormatTypes(format); ContinuousFileReaderOperator<FileInputSplit> initReader = new ContinuousFileReaderOperator<>(format); initReader.setOutputType(typeInfo, new ExecutionConfig()); OneInputStreamOperatorTestHarness<TimestampedFileInputSplit, FileInputSplit> testHarness = new OneInputStreamOperatorTestHarness<>( initReader); testHarness.setTimeCharacteristic(TimeCharacteristic.EventTime); testHarness.setup(); OperatorStateHandles operatorStateHandles = OperatorSnapshotUtil.readStateHandle( OperatorSnapshotUtil.getResourceFilename("reader-migration-test-flink1.2-snapshot")); testHarness.initializeState(operatorStateHandles); testHarness.open(); latch.trigger(); // ... and wait for the operators to close gracefully synchronized (testHarness.getCheckpointLock()) { testHarness.close(); } TimestampedFileInputSplit split1 = new TimestampedFileInputSplit(0, 3, new Path("test/test1"), 0, 100, null); TimestampedFileInputSplit split2 = new TimestampedFileInputSplit(10, 2, new Path("test/test2"), 101, 200, null); TimestampedFileInputSplit split3 = new TimestampedFileInputSplit(10, 1, new Path("test/test2"), 0, 100, null); TimestampedFileInputSplit split4 = new TimestampedFileInputSplit(11, 0, new Path("test/test3"), 0, 100, null); // compare if the results contain what they should contain and also if // they are the same, as they should. Assert.assertTrue(testHarness.getOutput().contains(new StreamRecord<>(split1))); Assert.assertTrue(testHarness.getOutput().contains(new StreamRecord<>(split2))); Assert.assertTrue(testHarness.getOutput().contains(new StreamRecord<>(split3))); Assert.assertTrue(testHarness.getOutput().contains(new StreamRecord<>(split4))); } /** * Manually run this to write binary snapshot data. Remove @Ignore to run. */ @Ignore @Test public void writeMonitoringSourceSnapshot() throws Exception { File testFolder = tempFolder.newFolder(); long fileModTime = Long.MIN_VALUE; for (int i = 0; i < 1; i++) { Tuple2<File, String> file = createFileAndFillWithData(testFolder, "file", i, "This is test line."); fileModTime = file.f0.lastModified(); } TextInputFormat format = new TextInputFormat(new Path(testFolder.getAbsolutePath())); final ContinuousFileMonitoringFunction<String> monitoringFunction = new ContinuousFileMonitoringFunction<>( format, FileProcessingMode.PROCESS_CONTINUOUSLY, 1, INTERVAL); StreamSource<TimestampedFileInputSplit, ContinuousFileMonitoringFunction<String>> src = new StreamSource<>( monitoringFunction); final AbstractStreamOperatorTestHarness<TimestampedFileInputSplit> testHarness = new AbstractStreamOperatorTestHarness<>( src, 1, 1, 0); testHarness.open(); final Throwable[] error = new Throwable[1]; final OneShotLatch latch = new OneShotLatch(); // run the source asynchronously Thread runner = new Thread() { @Override public void run() { try { monitoringFunction.run(new DummySourceContext() { @Override public void collect(TimestampedFileInputSplit element) { latch.trigger(); } @Override public void markAsTemporarilyIdle() { } }); } catch (Throwable t) { t.printStackTrace(); error[0] = t; } } }; runner.start(); if (!latch.isTriggered()) { latch.await(); } final OperatorStateHandles snapshot; synchronized (testHarness.getCheckpointLock()) { snapshot = testHarness.snapshot(0L, 0L); } OperatorSnapshotUtil.writeStateHandle(snapshot, "src/test/resources/monitoring-function-migration-test-" + fileModTime + "-flink1.2-snapshot"); monitoringFunction.cancel(); runner.join(); testHarness.close(); } @Test public void testMonitoringSourceRestore() throws Exception { File testFolder = tempFolder.newFolder(); Long expectedModTime = Long.parseLong("1493116191000"); TextInputFormat format = new TextInputFormat(new Path(testFolder.getAbsolutePath())); final ContinuousFileMonitoringFunction<String> monitoringFunction = new ContinuousFileMonitoringFunction<>( format, FileProcessingMode.PROCESS_CONTINUOUSLY, 1, INTERVAL); StreamSource<TimestampedFileInputSplit, ContinuousFileMonitoringFunction<String>> src = new StreamSource<>( monitoringFunction); final AbstractStreamOperatorTestHarness<TimestampedFileInputSplit> testHarness = new AbstractStreamOperatorTestHarness<>( src, 1, 1, 0); testHarness.setup(); OperatorStateHandles operatorStateHandles = OperatorSnapshotUtil.readStateHandle(OperatorSnapshotUtil .getResourceFilename("monitoring-function-migration-test-1493116191000-flink1.2-snapshot")); testHarness.initializeState(operatorStateHandles); testHarness.open(); Assert.assertEquals((long) expectedModTime, monitoringFunction.getGlobalModificationTime()); } private static class BlockingFileInputFormat extends FileInputFormat<FileInputSplit> { private static final long serialVersionUID = -6727603565381560267L; private final OneShotLatch latch; private FileInputSplit split; private boolean reachedEnd; BlockingFileInputFormat(OneShotLatch latch, Path filePath) { super(filePath); this.latch = latch; this.reachedEnd = false; } @Override public void open(FileInputSplit fileSplit) throws IOException { this.split = fileSplit; this.reachedEnd = false; } @Override public boolean reachedEnd() throws IOException { if (!latch.isTriggered()) { try { latch.await(); } catch (InterruptedException e) { e.printStackTrace(); } } return reachedEnd; } @Override public FileInputSplit nextRecord(FileInputSplit reuse) throws IOException { this.reachedEnd = true; return split; } @Override public void close() { } } private abstract static class DummySourceContext implements SourceFunction.SourceContext<TimestampedFileInputSplit> { private final Object lock = new Object(); @Override public void collectWithTimestamp(TimestampedFileInputSplit element, long timestamp) { } @Override public void emitWatermark(Watermark mark) { } @Override public Object getCheckpointLock() { return lock; } @Override public void close() { } } /** * Create a file with pre-determined String format of the form: * {@code fileIdx +": "+ sampleLine +" "+ lineNo}. * */ private Tuple2<File, String> createFileAndFillWithData(File base, String fileName, int fileIdx, String sampleLine) throws IOException { File file = new File(base, fileName + fileIdx); Assert.assertFalse(file.exists()); File tmp = new File(base, "." + fileName + fileIdx); FileOutputStream stream = new FileOutputStream(tmp); StringBuilder str = new StringBuilder(); for (int i = 0; i < LINES_PER_FILE; i++) { String line = fileIdx + ": " + sampleLine + " " + i + "\n"; str.append(line); stream.write(line.getBytes()); } stream.close(); FileUtils.moveFile(tmp, file); Assert.assertTrue("No result file present", file.exists()); return new Tuple2<>(file, str.toString()); } }