org.apache.flink.runtime.query.package-info 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.
*/
/**
* This package contains all KvState query related classes.
*
* TaskManager and JobManager
*
* State backends register queryable state instances at the {@link
* org.apache.flink.runtime.query.KvStateRegistry}.
* There is one registry per TaskManager. Registered KvState instances are
* reported to the JobManager, where they are aggregated at the {@link
* org.apache.flink.runtime.query.KvStateLocationRegistry}.
*
*
Instances of {@link org.apache.flink.runtime.query.KvStateLocation} contain
* all information needed for a client to query a KvState instance.
*
*
See also:
*
* - {@link org.apache.flink.runtime.query.KvStateRegistry}
* - {@link org.apache.flink.runtime.query.TaskKvStateRegistry}
* - {@link org.apache.flink.runtime.query.KvStateLocation}
* - {@link org.apache.flink.runtime.query.KvStateLocationRegistry}
*
*
* Client
*
* The {@link org.apache.flink.runtime.query.QueryableStateClient} is used
* to query KvState instances. The client takes care of {@link
* org.apache.flink.runtime.query.KvStateLocation} lookup and caching. Queries
* are then dispatched via the network client.
*
* JobManager Communication
*
* The JobManager is queried for {@link org.apache.flink.runtime.query.KvStateLocation}
* instances via the {@link org.apache.flink.runtime.query.KvStateLocationLookupService}.
* The client caches resolved locations and dispatches queries directly to the
* TaskManager.
*
*
TaskManager Communication
*
* After the location has been resolved, the TaskManager is queried via the
* {@link org.apache.flink.runtime.query.netty.KvStateClient}.
*/
package org.apache.flink.runtime.query;