rpuch commented on code in PR #1403: URL: https://github.com/apache/ignite-3/pull/1403#discussion_r1039581425
########## modules/api/src/main/java/org/apache/ignite/network/LogicalTopologyService.java: ########## @@ -0,0 +1,73 @@ +/* + * 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.ignite.network; + +import java.util.concurrent.CompletableFuture; + +/** + * Used for getting information about the cluster's Logical Topology. + * + * <p>There are 2 kinds of 'topologies': physical (see {@link TopologyService} and logical. + * <ul> + * <li>Physical topology consists of nodes mutually discovered by a membership protocol (like SWIM)</li> + * <li> + * Logical topology is a subset of a physical topology and only contains nodes that have successfully + * <a href="https://cwiki.apache.org/confluence/display/IGNITE/IEP-77%3A+Node+Join+Protocol+and+Initialization+for+Ignite+3";> + * joined the cluster</a> + * </li> + * </ul> + * + * @see <a href="https://cwiki.apache.org/confluence/display/IGNITE/IEP-77%3A+Node+Join+Protocol+and+Initialization+for+Ignite+3";> + * IEP-77: Node Join Protocol and Initialization for Ignite 3</a> + * @see TopologyService + */ +public interface LogicalTopologyService { + /** + * Adds a listener for logical topology events. + * + * <p>Event listeners are not guaranteed to see events they receive being consistent with the state acquired from + * {@link #logicalTopologyOnLeader()} (or local logical topology state obtained in other means). This means that, + * if you get an event with topology version N, event listener might see version M less or greater than N if it Review Comment: This information might be crucial for a user of listeners, so it probably should be here. On the other hand, users of `logicalTopologyOnLeader()` are not required to even know about listeners. If they use listeners, they will read this here and will be informed. So I would prefer to leave it as is. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
