org.apache.apex.api.EmbeddedAppLauncher Maven / Gradle / Ivy
/**
* 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.apex.api;
import org.apache.hadoop.conf.Configuration;
import com.datatorrent.api.Attribute;
import com.datatorrent.api.DAG;
import com.datatorrent.api.StreamingApplication;
/**
* Launcher for running the application directly in the current Java VM. For basic operations such as launching or
* stopping the application, {@link Launcher} can be used directly.
*
* @since 3.5.0
*/
public abstract class EmbeddedAppLauncher extends Launcher
{
/**
* Parameter to specify the time after which the application will be shutdown; pass 0 to run indefinitely.
*/
public static final Attribute RUN_MILLIS = new Attribute<>(0L);
/**
* Parameter to launch application asynchronously and return from launch immediately.
*/
public static final Attribute RUN_ASYNC = new Attribute<>(false);
/**
* Parameter to enable or disable heartbeat monitoring.
*/
public static final Attribute HEARTBEAT_MONITORING = new Attribute<>(true);
/**
* Parameter to serialize DAG before launch.
*/
public static final Attribute SERIALIZE_DAG = new Attribute<>(false);
static {
Attribute.AttributeMap.AttributeInitializer.initialize(EmbeddedAppLauncher.class);
}
public static EmbeddedAppLauncher newInstance()
{
return loadService(EmbeddedAppLauncher.class);
}
/**
* The EmbeddedAppHandle class would be useful in future to provide additional information without breaking backwards
* compatibility of the launchApp method
*/
public interface EmbeddedAppHandle extends AppHandle {}
/**
*
* getDAG.
*
* @return
*/
public abstract DAG getDAG();
/**
*
* cloneDAG.
*
* @return
* @throws java.lang.Exception
*/
public abstract DAG cloneDAG() throws Exception;
/**
* Build the logical plan through the given streaming application instance and/or from configuration.
*
* The plan will be constructed through {@link StreamingApplication#populateDAG}. If configuration properties are
* specified, they function as override, as would be the case when launching an application through CLI.
*
* This method can also be used to construct the plan declaratively from configuration only, by passing null for the
* application. In this case the configuration contains all operators and streams.
*
*
* @param app
* @param conf
* @return
* @throws Exception
* @since 0.3.5
*/
public abstract DAG prepareDAG(StreamingApplication app, Configuration conf) throws Exception;
/**
* Shortcut to run an application. Used for testing.
*
* @param app
* @param runMillis
*/
public static void runApp(StreamingApplication app, int runMillis)
{
runApp(app, null, runMillis);
}
/**
* Shortcut to run an application with the modified configuration.
*
* @param app - Application to be run
* @param configuration - Configuration
* @param runMillis - The time after which the application will be shutdown; pass 0 to run indefinitely.
*/
public static void runApp(StreamingApplication app, Configuration configuration, int runMillis)
{
EmbeddedAppLauncher launcher = newInstance();
Attribute.AttributeMap launchAttributes = new Attribute.AttributeMap.DefaultAttributeMap();
launchAttributes.put(RUN_MILLIS, (long)runMillis);
launcher.launchApp(app, configuration, launchAttributes);
}
}