SERVER-15089 remove fatal state and refactor rollback to use replcoord

1 files changed, 67 insertions, 0 deletions

diff --git a/src/mongo/db/repl/rs_rollback.h b/src/mongo/db/repl/rs_rollback.h
new file mode 100644
index 00000000000..8c5644f816a
--- /dev/null
+++ b/src/mongo/db/repl/rs_rollback.h
@@ -0,0 +1,67 @@
+/**
+ *    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 OpTime;
+
+namespace repl {
+    class OplogReader; 
+    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,
+                      OpTime lastOpTimeWritten,
+                      OplogReader* oplogreader,
+                      ReplicationCoordinator* replCoord);
+
+}
+}