org.voltcore.messaging.RecoveryMessage Maven / Gradle / Ivy
/* This file is part of VoltDB.
* Copyright (C) 2008-2018 VoltDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License as
* published by the Free Software Foundation, either version 3 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Affero General Public License for more details.
*
* You should have received a copy of the GNU Affero General Public License
* along with VoltDB. If not, see .
*/
package org.voltcore.messaging;
import java.nio.ByteBuffer;
import org.voltdb.iv2.TxnEgo;
/**
* Message containing recovery data for a partition/table pair.
*
* It is kind of obfuscated but the recovery message id is used for picking a class
* to deserialize the message. There is also a recovery message type, that is independent of the recovery message id.
* There is only one recovery message id but many recovery message types for this different phases and steps of
* recovery.
*/
public class RecoveryMessage extends VoltMessage {
/** Empty constructor for de-serialization */
public RecoveryMessage() {
m_subject = Subject.DEFAULT.getId();
m_recoveryMessagesAvailable = true;
}
private long m_txnId;
private long m_hsId;
// Is the source site ready to handle the rejoin?
private boolean m_isSourceReady = true;
/**
* Reuse this message to indicate that an ack was received and it is a good idea to wake up
* and do more work. The noarg constructor sets this to true so it can be delivered directly to the mailbox
* by an IO thread. initFromBuffer sets it to false so that other messages don't get mixed up.
*/
private boolean m_recoveryMessagesAvailable;
public boolean recoveryMessagesAvailable() {
return m_recoveryMessagesAvailable;
}
/**
* Constructor takes a ByteBuffer that already has enough space for the header and
* sets the source siteId followed by the last committed txnId at the partition before recovery begins.
* The purpose of this message is to inform the source partition of what txnId the recovering partition
* decided to stop after (stops after hearing from all initiators)
* before syncing so that the source partition can decide what txnId the partitions
* will sync at (will be some txnId >= the one in this message).
*
* This constructor is used to generate the recovery message sent by the source partition to
* the recovering partition in response to the Initiate message received from the recovering partition.
* The purpose of this message is to inform the recovering partition of what txnId the source partition
* decided to stop after before syncing so that the recovering partition can start executing stored procedures
* at the correct txnId.
*/
public RecoveryMessage(long sourceHSId, long txnId, long hsId) {
m_subject = Subject.DEFAULT.getId();
if (sourceHSId == -1) {
throw new RuntimeException("No way");
}
m_sourceHSId = sourceHSId;
m_recoveryMessagesAvailable = false;
m_txnId = txnId;
m_hsId = hsId;
}
/**
* Constructs a recovery message sent to the rejoining site as a response to
* the recovery request. It's used to tell the recovering site that the
* source site is not ready to handle the recovery request, the recovering
* site should retry later.
*
* @param isSourceReady
*/
public RecoveryMessage(boolean isSourceReady) {
m_isSourceReady = isSourceReady;
}
@Override
public int getSerializedSize() {
int msgsize = super.getSerializedSize();
msgsize +=
8 + // m_sourceHSId
8 + // m_txnId
1 + // is source ready
8; // m_hsId
return msgsize;
}
@Override
public void flattenToBuffer(ByteBuffer buf) {
buf.put(VoltMessageFactory.RECOVERY_ID);
buf.putLong( m_sourceHSId);
buf.putLong( m_txnId);
buf.put(m_isSourceReady ? 1 : (byte) 0);
buf.putLong( m_hsId);
assert(buf.capacity() == buf.position());
buf.limit(buf.position());
}
public long txnId() {
return m_txnId;
}
public long sourceSite() {
return m_sourceHSId;
}
public long getHSId() {
return m_hsId;
}
public boolean isSourceReady() {
return m_isSourceReady;
}
@Override
public void initFromBuffer(ByteBuffer buf) {
m_recoveryMessagesAvailable = false;
m_sourceHSId = buf.getLong();
m_txnId = buf.getLong();
m_isSourceReady = buf.get() == 1;
m_hsId = buf.getLong();
assert(buf.capacity() == buf.position());
}
@Override
public String getMessageInfo() {
return "RecoveryMessage TxnId:" + TxnEgo.txnIdToString(m_txnId);
}
}