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/**
* Copyright (C) 2014 MongoDB Inc.
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU Affero General Public License, version 3,
* as published by the Free Software Foundation.
*
* 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 this program. If not, see <http://www.gnu.org/licenses/>.
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
namespace mongo {
class OperationContext;
class Timestamp;
namespace repl {
class OplogReader;
class OpTime;
class ReplicationCoordinator;
/**
* Initiates the rollback process.
* This function assumes the preconditions for undertaking rollback have already been met;
* we have ops in our oplog that our sync source does not have, and we are not currently
* PRIMARY.
* The rollback procedure is:
* - find the common point between this node and its sync source
* - undo operations by fetching all documents affected, then replaying
* the sync source's oplog until we reach the time in the oplog when we fetched the last
* document.
* This function can throw std::exception on failures.
* This function runs a command on the sync source to detect if the sync source rolls back
* while our rollback is in progress.
*
* @param txn Used to read and write from this node's databases
* @param lastOpTimeWritten The last OpTime applied by the applier
* @param oplogreader Must already be connected to a sync source. Used to fetch documents.
* @param replCoord Used to track the rollback ID and to change the follower state
*
* Failures: some failure cases are fatal; others throw std::exception.
*/
void syncRollback(OperationContext* txn,
const OpTime& lastOpTimeWritten,
OplogReader* oplogreader,
ReplicationCoordinator* replCoord);
}
}
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