001 /**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017 package org.apache.camel.spi;
018
019 import java.util.List;
020 import java.util.concurrent.TimeUnit;
021
022 import org.apache.camel.CamelContext;
023 import org.apache.camel.Service;
024
025 /**
026 * Pluggable shutdown strategy executed during shutdown of routes.
027 * <p/>
028 * Shutting down routes in a reliable and graceful manner is not a trivial task. Therefore Camel provides a pluggable
029 * strategy allowing 3rd party to use their own strategy if needed.
030 * <p/>
031 * The key problem is to stop the input consumers for the routes such that no new messages is coming into Camel.
032 * But at the same time still keep the routes running so the existing in flight exchanges can still be run to
033 * completion. On top of that there are some in memory components (such as SEDA) which may have pending messages
034 * on its in memory queue which we want to run to completion as well, otherwise they will get lost.
035 * <p/>
036 * Camel provides a default strategy which supports all that that can be used as inspiration for your own strategy.
037 *
038 * @version $Revision: 893963 $
039 * @see org.apache.camel.spi.ShutdownAware
040 */
041 public interface ShutdownStrategy extends Service {
042
043 /**
044 * Shutdown the routes
045 *
046 * @param context the camel context
047 * @param routes the routes, ordered by the order they was started
048 * @throws Exception is thrown if error shutting down the consumers, however its preferred to avoid this
049 */
050 void shutdown(CamelContext context, List<RouteStartupOrder> routes) throws Exception;
051
052 /**
053 * Set an timeout to wait for the shutdown to complete.
054 * <p/>
055 * Setting a value of 0 or negative will disable timeout and wait until complete
056 * (potential blocking forever)
057 *
058 * @param timeout timeout in millis
059 */
060 void setTimeout(long timeout);
061
062 /**
063 * Gets the timeout.
064 * <p/>
065 * Use 0 or a negative value to disable timeout
066 *
067 * @return the timeout
068 */
069 long getTimeout();
070
071 /**
072 * Set the time unit to use
073 *
074 * @param timeUnit the unit to use
075 */
076 void setTimeUnit(TimeUnit timeUnit);
077
078 /**
079 * Gets the time unit used
080 *
081 * @return the time unit
082 */
083 TimeUnit getTimeUnit();
084
085 /**
086 * Sets whether to force shutdown of all consumers when a timeout occurred and thus
087 * not all consumers was shutdown within that period.
088 * <p/>
089 * You should have good reasons to set this option to <tt>false</tt> as it means that the routes
090 * keep running and is halted abruptly when {@link CamelContext} has been shutdown.
091 *
092 * @param shutdownNowOnTimeout <tt>true</tt> to force shutdown, <tt>false</tt> to leave them running
093 */
094 void setShutdownNowOnTimeout(boolean shutdownNowOnTimeout);
095
096 /**
097 * whether to force shutdown of all consumers when a timeout occurred.
098 *
099 * @return force shutdown or not
100 */
101 boolean isShutdownNowOnTimeout();
102 }