| /* |
| * 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.cassandra.locator; |
| |
| import java.net.UnknownHostException; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.List; |
| import java.util.Map; |
| |
| import com.google.common.annotations.VisibleForTesting; |
| |
| import org.apache.cassandra.config.CassandraRelevantProperties; |
| import org.apache.cassandra.config.Config; |
| import org.apache.cassandra.config.DatabaseDescriptor; |
| import org.apache.cassandra.utils.FBUtilities; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| public class SimpleSeedProvider implements SeedProvider |
| { |
| private static final Logger logger = LoggerFactory.getLogger(SimpleSeedProvider.class); |
| @VisibleForTesting |
| public static final String SEEDS_KEY = "seeds"; |
| @VisibleForTesting |
| public static final String RESOLVE_MULTIPLE_IP_ADDRESSES_PER_DNS_RECORD_KEY = "resolve_multiple_ip_addresses_per_dns_record"; |
| private static final int SEED_COUNT_WARN_THRESHOLD = CassandraRelevantProperties.SEED_COUNT_WARN_THRESHOLD.getInt(20); |
| |
| private final String[] defaultSeeds; |
| |
| public SimpleSeedProvider(Map<String, String> args) |
| { |
| defaultSeeds = new String[] { FBUtilities.getLocalAddressAndPort().getHostAddress(true) }; |
| } |
| |
| public List<InetAddressAndPort> getSeeds() |
| { |
| Config conf; |
| try |
| { |
| conf = DatabaseDescriptor.loadConfig(); |
| } |
| catch (Exception e) |
| { |
| throw new AssertionError(e); |
| } |
| |
| assert conf.seed_provider != null : "conf.seed_provider is null!"; |
| |
| boolean resolveMultipleIps; |
| String[] hosts; |
| |
| Map<String, String> parameters = conf.seed_provider.parameters; |
| if (parameters == null) |
| { |
| resolveMultipleIps = false; |
| hosts = defaultSeeds; |
| } |
| else |
| { |
| hosts = parameters.getOrDefault(SEEDS_KEY, defaultSeeds[0]).split(",", -1); |
| resolveMultipleIps = Boolean.parseBoolean(parameters.getOrDefault(RESOLVE_MULTIPLE_IP_ADDRESSES_PER_DNS_RECORD_KEY, Boolean.FALSE.toString())); |
| } |
| |
| List<InetAddressAndPort> seeds = new ArrayList<>(hosts.length); |
| |
| for (String host : hosts) |
| { |
| try |
| { |
| if (!host.trim().isEmpty()) |
| { |
| if (resolveMultipleIps) |
| { |
| List<InetAddressAndPort> resolvedSeeds = InetAddressAndPort.getAllByName(host.trim()); |
| seeds.addAll(resolvedSeeds); |
| logger.debug("{} resolves to {}", host, resolvedSeeds); |
| } |
| else |
| { |
| InetAddressAndPort addressAndPort = InetAddressAndPort.getByName(host.trim()); |
| seeds.add(addressAndPort); |
| logger.debug("Only resolving one IP per DNS record - {} resolves to {}", host, addressAndPort); |
| } |
| } |
| } |
| catch (UnknownHostException ex) |
| { |
| // not fatal... DD will bark if there end up being zero seeds. |
| logger.warn("Seed provider couldn't lookup host {}", host); |
| } |
| } |
| |
| if (seeds.size() > SEED_COUNT_WARN_THRESHOLD) |
| logger.warn("Seed provider returned more than {} seeds. " + |
| "A large seed list may impact effectiveness of the third gossip round.", |
| SEED_COUNT_WARN_THRESHOLD); |
| |
| return Collections.unmodifiableList(seeds); |
| } |
| } |