[flink] 01/04: [FLINK-16225] Improve metaspace out-of-memory error handling thrown in user code

[az...@apache.org]

This is an automated email from the ASF dual-hosted git repository.

azagrebin pushed a commit to branch release-1.10
in repository https://gitbox.apache.org/repos/asf/flink.git

commit 2c934ff2a42fe256c2a1174788cbe55c05e8e323
Author: Andrey Zagrebin <az...@apache.org>
AuthorDate: Sun Mar 15 14:26:05 2020 +0300

    [FLINK-16225] Improve metaspace out-of-memory error handling thrown in user code
    
    Improve error message, explaining the possible reasons and ways to resolve.
    In case of metaspace OOM error, try a graceful TM shutdown.
    
    This closes #11408.
---
 .../java/org/apache/flink/util/ExceptionUtils.java | 52 ++++++++++++++++++++++
 .../runtime/taskexecutor/TaskManagerRunner.java    |  8 +++-
 .../org/apache/flink/runtime/taskmanager/Task.java |  2 +
 3 files changed, 60 insertions(+), 2 deletions(-)

diff --git a/flink-core/src/main/java/org/apache/flink/util/ExceptionUtils.java b/flink-core/src/main/java/org/apache/flink/util/ExceptionUtils.java
index ddd0276..5fc1bfe 100644
--- a/flink-core/src/main/java/org/apache/flink/util/ExceptionUtils.java
+++ b/flink-core/src/main/java/org/apache/flink/util/ExceptionUtils.java
@@ -25,6 +25,7 @@
 package org.apache.flink.util;
 
 import org.apache.flink.annotation.Internal;
+import org.apache.flink.configuration.TaskManagerOptions;
 import org.apache.flink.util.function.RunnableWithException;
 
 import javax.annotation.Nullable;
@@ -48,6 +49,14 @@ public final class ExceptionUtils {
 	/** The stringified representation of a null exception reference. */
 	public static final String STRINGIFIED_NULL_EXCEPTION = "(null)";
 
+	private static final String TM_METASPACE_OOM_ERROR_MESSAGE = String.format(
+		"Metaspace. The metaspace out-of-memory error has occurred. This can mean two things: either the job requires " +
+			"a larger size of JVM metaspace to load classes or there is a class loading leak. In the first case " +
+			"'%s' configuration option should be increased. If the error persists (usually in cluster after " +
+			"several job (re-)submissions) then there is probably a class loading leak which has to be " +
+			"investigated and fixed. The task executor has to be shutdown...",
+		TaskManagerOptions.JVM_METASPACE.key());
+
 	/**
 	 * Makes a string representation of the exception's stack trace, or "(null)", if the
 	 * exception is null.
@@ -110,6 +119,49 @@ public final class ExceptionUtils {
 	}
 
 	/**
+	 * Generates new {@link OutOfMemoryError} with more detailed message.
+	 *
+	 * <p>This method improves error message for metaspace {@link OutOfMemoryError}.
+	 * It adds description of possible causes and ways of resolution.
+	 *
+	 * @param exception The exception to enrich.
+	 * @return either enriched exception if needed or the original one.
+	 */
+	public static Throwable enrichTaskManagerOutOfMemoryError(Throwable exception) {
+		if (isMetaspaceOutOfMemoryError(exception)) {
+			return changeOutOfMemoryErrorMessage(exception, TM_METASPACE_OOM_ERROR_MESSAGE);
+		}
+		return exception;
+	}
+
+	private static OutOfMemoryError changeOutOfMemoryErrorMessage(Throwable exception, String newMessage) {
+		Preconditions.checkArgument(exception instanceof OutOfMemoryError);
+		if (exception.getMessage().equals(newMessage)) {
+			return (OutOfMemoryError) exception;
+		}
+		OutOfMemoryError newError = new OutOfMemoryError(newMessage);
+		newError.initCause(exception.getCause());
+		newError.setStackTrace(exception.getStackTrace());
+		return newError;
+	}
+
+	/**
+	 * Checks whether the given exception indicates a JVM metaspace out-of-memory error.
+	 *
+	 * @param t The exception to check.
+	 * @return True, if the exception is the metaspace {@link OutOfMemoryError}, false otherwise.
+	 */
+	public static boolean isMetaspaceOutOfMemoryError(Throwable t) {
+		return isOutOfMemoryErrorWithMessageStartingWith(t, "Metaspace");
+	}
+
+	private static boolean isOutOfMemoryErrorWithMessageStartingWith(Throwable t, String prefix) {
+		// the exact matching of the class is checked to avoid matching any custom subclasses of OutOfMemoryError
+		// as we are interested in the original exceptions, generated by JVM.
+		return t.getClass() == OutOfMemoryError.class && t.getMessage() != null && t.getMessage().startsWith(prefix);
+	}
+
+	/**
 	 * Rethrows the given {@code Throwable}, if it represents an error that is fatal to the JVM.
 	 * See {@link ExceptionUtils#isJvmFatalError(Throwable)} for a definition of fatal errors.
 	 *
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/taskexecutor/TaskManagerRunner.java b/flink-runtime/src/main/java/org/apache/flink/runtime/taskexecutor/TaskManagerRunner.java
index ca93e32..8ed4fe4 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/taskexecutor/TaskManagerRunner.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/taskexecutor/TaskManagerRunner.java
@@ -246,9 +246,13 @@ public class TaskManagerRunner implements FatalErrorHandler, AutoCloseableAsync
 
 	@Override
 	public void onFatalError(Throwable exception) {
-		LOG.error("Fatal error occurred while executing the TaskManager. Shutting it down...", exception);
+		Throwable enrichedException = ExceptionUtils.enrichTaskManagerOutOfMemoryError(exception);
+		LOG.error("Fatal error occurred while executing the TaskManager. Shutting it down...", enrichedException);
 
-		if (ExceptionUtils.isJvmFatalOrOutOfMemoryError(exception)) {
+		// In case of the Metaspace OutOfMemoryError, we expect that the graceful shutdown is possible,
+		// as it does not usually require more class loading to fail again with the Metaspace OutOfMemoryError.
+		if (ExceptionUtils.isJvmFatalOrOutOfMemoryError(enrichedException) &&
+				!ExceptionUtils.isMetaspaceOutOfMemoryError(enrichedException)) {
 			terminateJVM();
 		} else {
 			closeAsync();
diff --git a/flink-runtime/src/main/java/org/apache/flink/runtime/taskmanager/Task.java b/flink-runtime/src/main/java/org/apache/flink/runtime/taskmanager/Task.java
index 3723f1a..689ada8 100644
--- a/flink-runtime/src/main/java/org/apache/flink/runtime/taskmanager/Task.java
+++ b/flink-runtime/src/main/java/org/apache/flink/runtime/taskmanager/Task.java
@@ -741,6 +741,8 @@ public class Task implements Runnable, TaskSlotPayload, TaskActions, PartitionPr
 			// an exception was thrown as a side effect of cancelling
 			// ----------------------------------------------------------------
 
+			t = ExceptionUtils.enrichTaskManagerOutOfMemoryError(t);
+
 			try {
 				// check if the exception is unrecoverable
 				if (ExceptionUtils.isJvmFatalError(t) ||