org.apache.spark.ExecutorPlugin 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.spark;
import org.apache.spark.annotation.DeveloperApi;
/**
* A plugin which can be automatically instantiated within each Spark executor. Users can specify
* plugins which should be created with the "spark.executor.plugins" configuration. An instance
* of each plugin will be created for every executor, including those created by dynamic allocation,
* before the executor starts running any tasks.
*
* The specific api exposed to the end users still considered to be very unstable. We will
* hopefully be able to keep compatibility by providing default implementations for any methods
* added, but make no guarantees this will always be possible across all Spark releases.
*
* Spark does nothing to verify the plugin is doing legitimate things, or to manage the resources
* it uses. A plugin acquires the same privileges as the user running the task. A bad plugin
* could also interfere with task execution and make the executor fail in unexpected ways.
*/
@DeveloperApi
public interface ExecutorPlugin {
/**
* Initialize the executor plugin.
*
* Each executor will, during its initialization, invoke this method on each
* plugin provided in the spark.executor.plugins configuration.
*
* Plugins should create threads in their implementation of this method for
* any polling, blocking, or intensive computation.
*/
default void init() {}
/**
* Clean up and terminate this plugin.
*
* This function is called during the executor shutdown phase. The executor
* will wait for the plugin to terminate before continuing its own shutdown.
*/
default void shutdown() {}
}