kaisun2000 commented on a change in pull request #775: WIP: Add HttpRoutingDataReader URL: https://github.com/apache/helix/pull/775#discussion_r382318431
########## File path: zookeeper-api/src/main/java/org/apache/helix/zookeeper/util/HttpRoutingDataReader.java ########## @@ -0,0 +1,81 @@ +package org.apache.helix.zookeeper.util; + +/* + * 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. + */ + +import java.io.IOException; +import java.util.HashMap; +import java.util.List; +import java.util.Map; + +import org.apache.http.HttpEntity; +import org.apache.http.client.ClientProtocolException; +import org.apache.http.client.methods.CloseableHttpResponse; +import org.apache.http.client.methods.HttpGet; +import org.apache.http.impl.client.CloseableHttpClient; +import org.apache.http.impl.client.HttpClients; +import org.apache.http.util.EntityUtils; +import org.codehaus.jackson.map.ObjectMapper; + + +public class HttpRoutingDataReader { + private static final ObjectMapper OBJECT_MAPPER = new ObjectMapper(); + + /** + * This class is a Singleton. + */ + private HttpRoutingDataReader() { + } + + /** + * Fetches routing data from the data source via HTTP. + * @return a mapping from "metadata store realm addresses" to lists of "metadata store sharding keys", where the sharding keys in a value list all route to the realm address in the key disallows a meaningful mapping to be returned + */ + public static Map<String, List<String>> getRoutingData(String msdsEndpoint) { + + Map<String, List<String>> rawRoutingData = new HashMap<>(); + + HttpGet requestAllRealmNames = + new HttpGet(msdsEndpoint); //TODO: construct an endpoint once REST endpoint is finalized + try (CloseableHttpClient httpClient = HttpClients.createDefault(); + CloseableHttpResponse response = httpClient.execute(requestAllRealmNames)) { Review comment: My thinking is that do we have a singleton class that would use this class of HttpRoutingDataReader upon application initialization to read and cache the routing data. So that later zkclient (shared, dedicated) will all use this cached data? or we will just use this class itself to do the cache? ---------------------------------------------------------------- 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. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
