| /* |
| * 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.samza.context; |
| |
| |
| /** |
| * An {@link ApplicationContainerContext} instance can be used for holding per-container runtime state and objects |
| * and managing their lifecycle. This context is shared across all tasks in the container. |
| * <p> |
| * Use {@link org.apache.samza.application.descriptors.ApplicationDescriptor#withApplicationContainerContextFactory} |
| * to provide the {@link ApplicationContainerContextFactory}. Use {@link Context#getApplicationContainerContext()} to |
| * get the created {@link ApplicationContainerContext} instance for the current container. |
| * <p> |
| * A unique instance of {@link ApplicationContainerContext} is created in each container. If the |
| * container moves or the container model changes (e.g. due to failure or re-balancing), a new instance is created. |
| * <p> |
| * Use the {@link ApplicationContainerContextFactory} to create any runtime state and objects, and the |
| * {@link ApplicationContainerContext#start()} and {@link ApplicationContainerContext#stop()} methods to |
| * manage their lifecycle. |
| * <p> |
| * Use {@link ApplicationTaskContext} to hold unique runtime state and objects for each task within a container. |
| * Use {@link ContainerContext} to access framework-provided context for a container. |
| * <p> |
| * Unlike its {@link ApplicationContainerContextFactory}, an implementation does not need to be |
| * {@link java.io.Serializable}. |
| */ |
| public interface ApplicationContainerContext { |
| /** |
| * Starts this {@link ApplicationContainerContext} before any tasks in the container are initialized and before |
| * processing begins. |
| * <p> |
| * If this throws an exception, the container will fail to start. |
| */ |
| void start(); |
| |
| /** |
| * Stops this {@link ApplicationContainerContext} after processing ends and after all tasks in the container |
| * are closed. |
| * <p> |
| * If this throws an exception, the container will fail to fully shut down. |
| */ |
| void stop(); |
| } |