ConfigStoreWithStableVersioning.java

/*
 * 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 gobblin.config.store.api;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

import gobblin.annotation.Alpha;
import gobblin.config.client.api.VersionStabilityPolicy;

/**
 * The ConfigStoreWithStableVersioning annotation is used to indicate that the configuration store
 * supports stable versioning. This means that:
 *
 * <ul>
 *   <li>Once published the version will remain available for at least a day even if it gets rolled
 *       back.</li>
 *   <li>The version and all its configuration objects are immutable.</li>
 * </ul>
 *
 * Version stability defines the possible outcomes for repeated calls to
 * {@link ConfigStore#getOwnConfig(ConfigKeyPath, String)}
 * for the same config key and version from the same or different JVMs. This is used in conjunction
 * with {@link VersionStabilityPolicy} to control client library behavior with respect to caching
 * config values.
 *
 * @author mitu
 *
 */
@Documented @Retention(value=RetentionPolicy.RUNTIME) @Target(value=ElementType.TYPE)
@Alpha
public @interface ConfigStoreWithStableVersioning {

}