+ * When {@link #limit} would be reached on append, past messages will be + * truncated from head, and a header telling the user about truncation will be + * prepended, with ellipses in between header and messages. + *
+ * Note that header and ellipses are not counted against {@link #limit}. + *
+ * An example: + * + *
+ * {@code
+ * // At the beginning it's an empty string
+ * final Appendable shortAppender = new BoundedAppender(80);
+ * // The whole message fits into limit
+ * shortAppender.append(
+ * "message1 this is a very long message but fitting into limit\n");
+ * // The first message is truncated, the second not
+ * shortAppender.append("message2 this is shorter than the previous one\n");
+ * // The first message is deleted, the second truncated, the third
+ * // preserved
+ * shortAppender.append("message3 this is even shorter message, maybe.\n");
+ * // The first two are deleted, the third one truncated, the last preserved
+ * shortAppender.append("message4 the shortest one, yet the greatest :)");
+ * // Current contents are like this:
+ * // Diagnostic messages truncated, showing last 80 chars out of 199:
+ * // ...s is even shorter message, maybe.
+ * // message4 the shortest one, yet the greatest :)
+ * }
+ *
+ * + * Note that null values are {@link #append(CharSequence) append}ed + * just like in {@link StringBuilder#append(CharSequence) original + * implementation}. + *
+ * Note that this class is not thread safe. + */ + @VisibleForTesting + static class BoundedAppender { + @VisibleForTesting + static final String TRUNCATED_MESSAGES_TEMPLATE = + "Diagnostic messages truncated, showing last " + + "%d chars out of %d:%n...%s"; + + private final int limit; + private final StringBuilder messages = new StringBuilder(); + private int totalCharacterCount = 0; + + BoundedAppender(final int limit) { + Preconditions.checkArgument(limit > 0, "limit should be positive"); + + this.limit = limit; + } + + /** + * Append a {@link CharSequence} considering {@link #limit}, truncating + * from the head of {@code csq} or {@link #messages} when necessary. + * + * @param csq the {@link CharSequence} to append + * @return this + */ + BoundedAppender append(final CharSequence csq) { + appendAndCount(csq); + checkAndCut(); + + return this; + } + + private void appendAndCount(final CharSequence csq) { + final int before = messages.length(); + messages.append(csq); + final int after = messages.length(); + totalCharacterCount += after - before; + } + + private void checkAndCut() { + if (messages.length() > limit) { + final int newStart = messages.length() - limit; + messages.delete(0, newStart); + } + } + + /** + * Get current length of messages considering truncates + * without header and ellipses. + * + * @return current length + */ + int length() { + return messages.length(); + } + + /** + * Get a string representation of the actual contents, displaying also a + * header and ellipses when there was a truncate. + * + * @return String representation of the {@link #messages} + */ + @Override + public String toString() { + if (messages.length() < totalCharacterCount) { + return String.format(TRUNCATED_MESSAGES_TEMPLATE, messages.length(), + totalCharacterCount, messages.toString()); + } + + return messages.toString(); + } + } } diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestBoundedAppender.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestBoundedAppender.java new file mode 100644 index 00000000000..9cb1e0404ff --- /dev/null +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestBoundedAppender.java @@ -0,0 +1,116 @@ +/** + * 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.hadoop.yarn.server.resourcemanager.rmapp.attempt; + +import org.junit.Rule; +import org.junit.Test; +import org.junit.rules.ExpectedException; + +import static org.junit.Assert.assertEquals; +import static org.apache.hadoop.yarn.server.resourcemanager.rmapp.attempt.RMAppAttemptImpl.BoundedAppender; + +/** + * Test class for {@link BoundedAppender}. + */ +public class TestBoundedAppender { + @Rule + public ExpectedException expected = ExpectedException.none(); + + @Test + public void initWithZeroLimitThrowsException() { + expected.expect(IllegalArgumentException.class); + expected.expectMessage("limit should be positive"); + + new BoundedAppender(0); + } + + @Test + public void nullAppendedNullStringRead() { + final BoundedAppender boundedAppender = new BoundedAppender(4); + boundedAppender.append(null); + + assertEquals("null appended, \"null\" read", "null", + boundedAppender.toString()); + } + + @Test + public void appendBelowLimitOnceValueIsReadCorrectly() { + final BoundedAppender boundedAppender = new BoundedAppender(2); + + boundedAppender.append("ab"); + + assertEquals("value appended is read correctly", "ab", + boundedAppender.toString()); + } + + @Test + public void appendValuesBelowLimitAreReadCorrectlyInFifoOrder() { + final BoundedAppender boundedAppender = new BoundedAppender(3); + + boundedAppender.append("ab"); + boundedAppender.append("cd"); + boundedAppender.append("e"); + boundedAppender.append("fg"); + + assertEquals("last values appended fitting limit are read correctly", + String.format(BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 3, 7, "efg"), + boundedAppender.toString()); + } + + @Test + public void appendLastAboveLimitPreservesLastMessagePostfix() { + final BoundedAppender boundedAppender = new BoundedAppender(3); + + boundedAppender.append("ab"); + boundedAppender.append("cde"); + boundedAppender.append("fghij"); + + assertEquals( + "last value appended above limit postfix is read correctly", String + .format(BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 3, 10, "hij"), + boundedAppender.toString()); + } + + @Test + public void appendMiddleAboveLimitPreservesLastMessageAndMiddlePostfix() { + final BoundedAppender boundedAppender = new BoundedAppender(3); + + boundedAppender.append("ab"); + boundedAppender.append("cde"); + + assertEquals("last value appended above limit postfix is read correctly", + String.format(BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 3, 5, "cde"), + boundedAppender.toString()); + + boundedAppender.append("fg"); + + assertEquals( + "middle value appended above limit postfix and last value are " + + "read correctly", + String.format(BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 3, 7, "efg"), + boundedAppender.toString()); + + boundedAppender.append("hijkl"); + + assertEquals( + "last value appended above limit postfix is read correctly", String + .format(BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 3, 12, "jkl"), + boundedAppender.toString()); + } +} \ No newline at end of file diff --git a/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestRMAppAttemptImplDiagnostics.java b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestRMAppAttemptImplDiagnostics.java new file mode 100644 index 00000000000..a160eb828a0 --- /dev/null +++ b/hadoop-yarn-project/hadoop-yarn/hadoop-yarn-server/hadoop-yarn-server-resourcemanager/src/test/java/org/apache/hadoop/yarn/server/resourcemanager/rmapp/attempt/TestRMAppAttemptImplDiagnostics.java @@ -0,0 +1,111 @@ +/** + * 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.hadoop.yarn.server.resourcemanager.rmapp.attempt; + +import org.apache.commons.lang.RandomStringUtils; +import org.apache.hadoop.conf.Configuration; +import org.apache.hadoop.yarn.api.records.ApplicationAttemptId; +import org.apache.hadoop.yarn.api.records.ApplicationId; +import org.apache.hadoop.yarn.conf.YarnConfiguration; +import org.apache.hadoop.yarn.event.Dispatcher; +import org.apache.hadoop.yarn.exceptions.YarnRuntimeException; +import org.apache.hadoop.yarn.server.resourcemanager.RMContext; +import org.junit.Rule; +import org.junit.Test; +import org.junit.rules.ExpectedException; + +import static org.junit.Assert.assertEquals; +import static org.mockito.Mockito.mock; +import static org.mockito.Mockito.when; + +/** + * Testing {@link RMAppAttemptImpl#diagnostics} scenarios. + */ +public class TestRMAppAttemptImplDiagnostics { + + @Rule + public ExpectedException expectedException = ExpectedException.none(); + + @Test + public void whenCreatedWithDefaultConfigurationSuccess() { + final Configuration configuration = new Configuration(); + configuration.setInt(YarnConfiguration.APP_ATTEMPT_DIAGNOSTICS_LIMIT_KC, + YarnConfiguration.DEFAULT_APP_ATTEMPT_DIAGNOSTICS_LIMIT_KC); + + createRMAppAttemptImpl(configuration); + } + + @Test + public void whenCreatedWithWrongConfigurationError() { + final Configuration configuration = new Configuration(); + configuration.setInt(YarnConfiguration.APP_ATTEMPT_DIAGNOSTICS_LIMIT_KC, 0); + + expectedException.expect(YarnRuntimeException.class); + + createRMAppAttemptImpl(configuration); + } + + @Test + public void whenAppendedWithinLimitMessagesArePreserved() { + final Configuration configuration = new Configuration(); + configuration.setInt(YarnConfiguration.APP_ATTEMPT_DIAGNOSTICS_LIMIT_KC, 1); + + final RMAppAttemptImpl appAttempt = createRMAppAttemptImpl(configuration); + + final String withinLimit = RandomStringUtils.random(1024); + appAttempt.appendDiagnostics(withinLimit); + + assertEquals("messages within limit should be preserved", withinLimit, + appAttempt.getDiagnostics()); + } + + @Test + public void whenAppendedBeyondLimitMessagesAreTruncated() { + final Configuration configuration = new Configuration(); + configuration.setInt(YarnConfiguration.APP_ATTEMPT_DIAGNOSTICS_LIMIT_KC, 1); + + final RMAppAttemptImpl appAttempt = createRMAppAttemptImpl(configuration); + + final String beyondLimit = RandomStringUtils.random(1025); + appAttempt.appendDiagnostics(beyondLimit); + + final String truncated = String.format( + RMAppAttemptImpl.BoundedAppender.TRUNCATED_MESSAGES_TEMPLATE, 1024, + 1025, beyondLimit.substring(1)); + + assertEquals("messages beyond limit should be truncated", truncated, + appAttempt.getDiagnostics()); + } + + private RMAppAttemptImpl createRMAppAttemptImpl( + final Configuration configuration) { + final ApplicationAttemptId mockApplicationAttemptId = + mock(ApplicationAttemptId.class); + final ApplicationId mockApplicationId = mock(ApplicationId.class); + when(mockApplicationAttemptId.getApplicationId()) + .thenReturn(mockApplicationId); + + final RMContext mockRMContext = mock(RMContext.class); + final Dispatcher mockDispatcher = mock(Dispatcher.class); + when(mockRMContext.getDispatcher()).thenReturn(mockDispatcher); + + return new RMAppAttemptImpl(mockApplicationAttemptId, mockRMContext, null, + null, null, configuration, false, null); + } +} \ No newline at end of file