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LiebingYuLiebingYu
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[server] Register signal handlers to log termination due to SIGTERM, SIGHUP and SIGINT
1 parent ae84521 commit 905ae1c

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4 files changed

+172
-1
lines changed

4 files changed

+172
-1
lines changed

‎fluss-server/src/main/java/org/apache/fluss/server/ServerBase.java‎

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Original file line numberDiff line numberDiff line change
@@ -31,6 +31,8 @@
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import org.apache.fluss.server.tablet.TabletServer;
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import org.apache.fluss.server.utils.ConfigurationParserUtils;
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import org.apache.fluss.server.utils.FatalErrorHandler;
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import org.apache.fluss.server.utils.LoggingSignalHandler;
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import org.apache.fluss.server.utils.OperatingSystem;
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import org.apache.fluss.server.utils.ShutdownHookUtil;
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import org.apache.fluss.utils.AutoCloseableAsync;
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import org.apache.fluss.utils.ExceptionUtils;
@@ -113,6 +115,17 @@ protected static void startServer(ServerBase server) {
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}
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public void start() throws Exception {
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try {
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if (!OperatingSystem.IS_WINDOWS) {
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new LoggingSignalHandler().register();
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}
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} catch (ReflectiveOperationException e) {
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LOG.warn(
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"Failed to register optional signal handler that logs a message when the process is terminated "
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+ "by a signal. Reason for registration failure is: ",
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e);
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}
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try {
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addShutDownHook();
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‎fluss-server/src/main/java/org/apache/fluss/server/tablet/TabletServer.java‎

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@@ -284,7 +284,7 @@ protected void startServices() throws Exception {
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@Override
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protected CompletableFuture<Result> closeAsync(Result result) {
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if (isShutDown.compareAndSet(false, true)) {
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LOG.info("Shutting down Tablet server ({}).", result);
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controlledShutDown();
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CompletableFuture<Void> serviceShutdownFuture = stopServices();

‎fluss-server/src/main/java/org/apache/fluss/server/utils/LoggingSignalHandler.java‎

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@@ -0,0 +1,123 @@
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/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
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* this work for additional information regarding copyright ownership.
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* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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package org.apache.fluss.server.utils;
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import org.slf4j.Logger;
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import org.slf4j.LoggerFactory;
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import java.lang.reflect.Constructor;
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import java.lang.reflect.InvocationHandler;
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import java.lang.reflect.InvocationTargetException;
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import java.lang.reflect.Method;
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import java.lang.reflect.Proxy;
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import java.util.Arrays;
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import java.util.List;
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import java.util.Map;
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import java.util.concurrent.ConcurrentHashMap;
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/**
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* A utility class to register signal handlers to log termination due to SIGTERM, SIGHUP and SIGINT
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* (control-c).
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*/
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public class LoggingSignalHandler {
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private static final Logger LOG = LoggerFactory.getLogger(LoggingSignalHandler.class);
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private static final List<String> SIGNALS = Arrays.asList("TERM", "INT", "HUP");
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private final Constructor<?> signalConstructor;
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private final Class<?> signalHandlerClass;
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private final Method signalHandleMethod;
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private final Method signalGetNameMethod;
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private final Method signalHandlerHandleMethod;
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/**
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* Create an instance of this class.
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*
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* @throws ReflectiveOperationException if the underlying API has changed in an incompatible
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* manner.
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*/
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public LoggingSignalHandler() throws ReflectiveOperationException {
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Class<?> signalClass = Class.forName("sun.misc.Signal");
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signalConstructor = signalClass.getConstructor(String.class);
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signalHandlerClass = Class.forName("sun.misc.SignalHandler");
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signalHandlerHandleMethod = signalHandlerClass.getMethod("handle", signalClass);
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signalHandleMethod = signalClass.getMethod("handle", signalClass, signalHandlerClass);
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signalGetNameMethod = signalClass.getMethod("getName");
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}
63+
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/**
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* Register signal handler to log termination due to SIGTERM, SIGHUP and SIGINT (control-c).
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* This method does not currently work on Windows.
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*
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* @implNote sun.misc.Signal and sun.misc.SignalHandler are described as "not encapsulated" in
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* <a href="http://openjdk.java.net/jeps/260">...</a>. However, they are not available in to
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* compile classpath if the `--release` flag is used. As a workaround, we rely on
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* reflection.
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*/
73+
public void register() throws ReflectiveOperationException {
74+
Map<String, Object> jvmSignalHandlers = new ConcurrentHashMap<>();
75+
76+
for (String signal : SIGNALS) {
77+
register(signal, jvmSignalHandlers);
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}
79+
LOG.info("Registered signal handlers for {}", String.join(", ", SIGNALS));
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}
81+
82+
private Object createSignalHandler(final Map<String, Object> jvmSignalHandlers) {
83+
InvocationHandler invocationHandler =
84+
new InvocationHandler() {
85+
86+
private String getName(Object signal) throws Throwable {
87+
try {
88+
return (String) signalGetNameMethod.invoke(signal);
89+
} catch (InvocationTargetException e) {
90+
throw e.getCause();
91+
}
92+
}
93+
94+
private void handle(Object signalHandler, Object signal)
95+
throws ReflectiveOperationException {
96+
signalHandlerHandleMethod.invoke(signalHandler, signal);
97+
}
98+
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@Override
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public Object invoke(Object proxy, Method method, Object[] args)
101+
throws Throwable {
102+
Object signal = args[0];
103+
LOG.info("Terminating process due to signal {}", signal);
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Object handler = jvmSignalHandlers.get(getName(signal));
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if (handler != null) handle(handler, signal);
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return null;
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}
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};
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return Proxy.newProxyInstance(
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LoggingSignalHandler.class.getClassLoader(),
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new Class<?>[] {signalHandlerClass},
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invocationHandler);
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}
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private void register(String signalName, final Map<String, Object> jvmSignalHandlers)
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throws ReflectiveOperationException {
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Object signal = signalConstructor.newInstance(signalName);
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Object signalHandler = createSignalHandler(jvmSignalHandlers);
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Object oldHandler = signalHandleMethod.invoke(null, signal, signalHandler);
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if (oldHandler != null) jvmSignalHandlers.put(signalName, oldHandler);
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}
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}

‎fluss-server/src/main/java/org/apache/fluss/server/utils/OperatingSystem.java‎

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@@ -0,0 +1,35 @@
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/*
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* Licensed to the Apache Software Foundation (ASF) under one or more
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* contributor license agreements. See the NOTICE file distributed with
4+
* this work for additional information regarding copyright ownership.
5+
* The ASF licenses this file to You under the Apache License, Version 2.0
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* (the "License"); you may not use this file except in compliance with
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* the License. You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
10+
*
11+
* Unless required by applicable law or agreed to in writing, software
12+
* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14+
* See the License for the specific language governing permissions and
15+
* limitations under the License.
16+
*/
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package org.apache.fluss.server.utils;
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import java.util.Locale;
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/** Utility class for operating system related helper functions. */
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public final class OperatingSystem {
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private OperatingSystem() {}
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public static final String NAME;
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public static final boolean IS_WINDOWS;
30+
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static {
32+
NAME = System.getProperty("os.name").toLowerCase(Locale.ROOT);
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IS_WINDOWS = NAME.startsWith("windows");
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}
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}

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