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本文主要研究一下artemis的gracefulShutdownEnabled
gracefulShutdownEnabled
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/config/impl/ConfigurationImpl.java
public class ConfigurationImpl implements Configuration, Serializable {
//......
private boolean gracefulShutdownEnabled = ActiveMQDefaultConfiguration.isDefaultGracefulShutdownEnabled();
private long gracefulShutdownTimeout = ActiveMQDefaultConfiguration.getDefaultGracefulShutdownTimeout();
//......
@Override
public boolean isGracefulShutdownEnabled() {
return gracefulShutdownEnabled;
}
@Override
public ConfigurationImpl setGracefulShutdownEnabled(final boolean enabled) {
gracefulShutdownEnabled = enabled;
return this;
}
@Override
public long getGracefulShutdownTimeout() {
return gracefulShutdownTimeout;
}
@Override
public ConfigurationImpl setGracefulShutdownTimeout(final long timeout) {
gracefulShutdownTimeout = timeout;
return this;
}
//......
}
- ConfigurationImpl定义了两个关于gracefulShutdown的属性，分别是gracefulShutdownEnabled(
默认为true)及gracefulShutdownTimeout(默认为-1)
ActiveMQServerImpl
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/server/impl/ActiveMQServerImpl.java
public class ActiveMQServerImpl implements ActiveMQServer {
//......
public final void stop(boolean failoverOnServerShutdown, boolean isExit) throws Exception {
stop(failoverOnServerShutdown, false, false, isExit);
}
public void stop(boolean failoverOnServerShutdown, final boolean criticalIOError, boolean restarting) {
this.stop(failoverOnServerShutdown, criticalIOError, restarting, false);
}
void stop(boolean failoverOnServerShutdown, final boolean criticalIOError, boolean restarting, boolean isShutdown) {
logger.debug("Stopping server");
synchronized (this) {
if (state == SERVER_STATE.STOPPED || state == SERVER_STATE.STOPPING) {
return;
}
state = SERVER_STATE.STOPPING;
if (fileStoreMonitor != null) {
fileStoreMonitor.stop();
fileStoreMonitor = null;
}
if (failoverOnServerShutdown) {
activation.sendLiveIsStopping();
}
stopComponent(connectorsService);
// we stop the groupingHandler before we stop the cluster manager so binding mappings
// aren't removed in case of failover
if (groupingHandler != null) {
managementService.removeNotificationListener(groupingHandler);
stopComponent(groupingHandler);
}
stopComponent(federationManager);
stopComponent(clusterManager);
if (remotingService != null) {
remotingService.pauseAcceptors();
}
// allows for graceful shutdown
if (remotingService != null && configuration.isGracefulShutdownEnabled()) {
long timeout = configuration.getGracefulShutdownTimeout();
try {
if (timeout == -1) {
remotingService.getConnectionCountLatch().await();
} else {
remotingService.getConnectionCountLatch().await(timeout);
}
} catch (InterruptedException e) {
ActiveMQServerLogger.LOGGER.interruptWhilstStoppingComponent(remotingService.getClass().getName());
}
}
freezeConnections();
}
//......
}
static void stopComponent(ActiveMQComponent component) {
try {
if (component != null) {
component.stop();
}
} catch (Throwable t) {
ActiveMQServerLogger.LOGGER.errorStoppingComponent(t, component.getClass().getName());
}
}
//......
}
- ActiveMQServerImpl在remotingService不为null且configuration.isGracefulShutdownEnabled()为true时会读取configuration.getGracefulShutdownTimeout()；若timeout为-1，则执行remotingService.getConnectionCountLatch().await()，否则执行remotingService.getConnectionCountLatch().await(timeout)
connectionCountLatch
activemq-artemis-2.11.0/artemis-server/src/main/java/org/apache/activemq/artemis/core/remoting/server/impl/RemotingServiceImpl.java
public class RemotingServiceImpl implements RemotingService, ServerConnectionLifeCycleListener {
//......
private final ReusableLatch connectionCountLatch = new ReusableLatch(0);
//......
public synchronized ReusableLatch getConnectionCountLatch() {
return connectionCountLatch;
}
public void connectionCreated(final ActiveMQComponent component,
final Connection connection,
final ProtocolManager protocol) {
if (server == null) {
throw new IllegalStateException("Unable to create connection, server hasn't finished starting up");
}
ConnectionEntry entry = protocol.createConnectionEntry((Acceptor) component, connection);
try {
if (server.hasBrokerConnectionPlugins()) {
server.callBrokerConnectionPlugins(plugin -> plugin.afterCreateConnection(entry.connection));
}
} catch (ActiveMQException t) {
logger.warn("Error executing afterCreateConnection plugin method: {}", t.getMessage(), t);
throw new IllegalStateException(t.getMessage(), t.getCause());
}
if (logger.isTraceEnabled()) {
logger.trace("Connection created " + connection);
}
connections.put(connection.getID(), entry);
connectionCountLatch.countUp();
totalConnectionCount.incrementAndGet();
}
public RemotingConnection removeConnection(final Object remotingConnectionID) {
ConnectionEntry entry = connections.remove(remotingConnectionID);
if (entry != null) {
logger.debug("RemotingServiceImpl::removing connection ID " + remotingConnectionID);
connectionCountLatch.countDown();
return entry.connection;
} else {
logger.debug("The connectionID::" + remotingConnectionID + " was already removed by some other module");
return null;
}
}
//......
}
- getConnectionCountLatch返回的是connectionCountLatch；connectionCreated方法会执行connectionCountLatch.countUp()；removeConnection方法会执行connectionCountLatch.countDown()
小结
ConfigurationImpl定义了两个关于gracefulShutdown的属性，分别是gracefulShutdownEnabled(默认为true)及gracefulShutdownTimeout(默认为-1)；ActiveMQServerImpl在remotingService不为null且configuration.isGracefulShutdownEnabled()为true时会读取configuration.getGracefulShutdownTimeout()；若timeout为-1，则执行remotingService.getConnectionCountLatch().await()，否则执行remotingService.getConnectionCountLatch().await(timeout)
