/*
 * 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.db;

import java.util.Collection;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import org.apache.cassandra.net.IVerbHandler;
import org.apache.cassandra.net.MessageIn;
import org.apache.cassandra.net.MessageOut;
import org.apache.cassandra.net.MessagingService;
import org.apache.cassandra.service.MigrationManager;

/**
 * Sends it's current schema state in form of row mutations in reply to the remote node's request.
 * Such a request is made when one of the nodes, by means of Gossip, detects schema disagreement in the ring.
 */
public class MigrationRequestVerbHandler implements IVerbHandler
{
    private static final Logger logger = LoggerFactory.getLogger(MigrationRequestVerbHandler.class);

    public void doVerb(MessageIn message, String id)
    {
        logger.debug("Received migration request from {}.", message.from);
        MessageOut<Collection<RowMutation>> response = new MessageOut<Collection<RowMutation>>(MessagingService.Verb.INTERNAL_RESPONSE,
                                                                                               SystemTable.serializeSchema(),
                                                                                               MigrationManager.MigrationsSerializer.instance);
        MessagingService.instance().sendReply(response, id, message.from);
    }
}
@@ -861,16 +861,46 @@
 lection;
+%0Aimport java.util.Collections;
 %0A%0Aimport
@@ -1705,24 +1705,430 @@
 sage.from);%0A
+%0A        if (message.version %3C MessagingService.VERSION_12)%0A            logger.debug(%22Returning empty response to the migration request from %7B%7D (version %3C 1.2).%22, message.from);%0A%0A        Collection%3CRowMutation%3E schema = message.version %3C MessagingService.VERSION_12%0A                                         ? Collections.EMPTY_SET%0A                                         : SystemTable.serializeSchema();%0A%0A
         Mess
@@ -2350,37 +2350,14 @@
     
-SystemTable.serializeS
+s
 chema
-()
 ,%0A  

Return empty schema to pre-1.2 nodes' migration requests