| /* |
| * 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.hints; |
| |
| import java.net.InetAddress; |
| import java.util.UUID; |
| |
| import org.slf4j.Logger; |
| import org.slf4j.LoggerFactory; |
| |
| import org.apache.cassandra.db.partitions.PartitionUpdate; |
| import org.apache.cassandra.net.IVerbHandler; |
| import org.apache.cassandra.net.MessageIn; |
| import org.apache.cassandra.net.MessagingService; |
| import org.apache.cassandra.serializers.MarshalException; |
| import org.apache.cassandra.service.StorageProxy; |
| import org.apache.cassandra.service.StorageService; |
| |
| /** |
| * Verb handler used both for hint dispatch and streaming. |
| * |
| * With the non-sstable format, we cannot just stream hint sstables on node decommission. So sometimes, at decommission |
| * time, we might have to stream hints to a non-owning host (say, if the owning host B is down during decommission of host A). |
| * In that case the handler just stores the received hint in its local hint store. |
| */ |
| public final class HintVerbHandler implements IVerbHandler<HintMessage> |
| { |
| private static final Logger logger = LoggerFactory.getLogger(HintVerbHandler.class); |
| |
| public void doVerb(MessageIn<HintMessage> message, int id) |
| { |
| UUID hostId = message.payload.hostId; |
| Hint hint = message.payload.hint; |
| |
| // If we see an unknown table id, it means the table, or one of the tables in the mutation, had been dropped. |
| // In that case there is nothing we can really do, or should do, other than log it go on. |
| // This will *not* happen due to a not-yet-seen table, because we don't transfer hints unless there |
| // is schema agreement between the sender and the receiver. |
| if (hint == null) |
| { |
| logger.trace("Failed to decode and apply a hint for {} - table with id {} is unknown", |
| hostId, |
| message.payload.unknownTableID); |
| reply(id, message.from); |
| return; |
| } |
| |
| // We must perform validation before applying the hint, and there is no other place to do it other than here. |
| try |
| { |
| hint.mutation.getPartitionUpdates().forEach(PartitionUpdate::validate); |
| } |
| catch (MarshalException e) |
| { |
| logger.warn("Failed to validate a hint for {} (table id {}) - skipped", hostId); |
| reply(id, message.from); |
| return; |
| } |
| |
| if (!hostId.equals(StorageService.instance.getLocalHostUUID())) |
| { |
| // the node is not the final destination of the hint (must have gotten it from a decommissioning node), |
| // so just store it locally, to be delivered later. |
| HintsService.instance.write(hostId, hint); |
| } |
| else if (!StorageProxy.instance.appliesLocally(hint.mutation)) |
| { |
| // the topology has changed, and we are no longer a replica of the mutation - since we don't know which node(s) |
| // it has been handed over to, re-address the hint to all replicas; see CASSANDRA-5902. |
| HintsService.instance.writeForAllReplicas(hint); |
| } |
| else |
| { |
| // the common path - the node is both the destination and a valid replica for the hint. |
| hint.apply(); |
| } |
| |
| reply(id, message.from); |
| } |
| |
| private static void reply(int id, InetAddress to) |
| { |
| MessagingService.instance().sendReply(HintResponse.message, id, to); |
| } |
| } |