SERVER-31007 Calculate rollback time limit correctly

1 files changed, 42 insertions, 0 deletions

diff --git a/src/mongo/db/repl/rollback_impl.h b/src/mongo/db/repl/rollback_impl.h
index 38230880d41..a94d11c93e4 100644
--- a/src/mongo/db/repl/rollback_impl.h
+++ b/src/mongo/db/repl/rollback_impl.h
@@ -93,6 +93,16 @@ struct RollbackStats {
      * The directory containing rollback data files, if any were written.
      */
     boost::optional<std::string> rollbackDataFileDirectory;
+
+    /**
+     * The last wall clock time on the branch of history being rolled back, if known.
+     */
+    boost::optional<Date_t> lastLocalWallClockTime;
+
+    /**
+     * The wall clock time at the common point, if known.
+     */
+    boost::optional<Date_t> commonPointWallClockTime;
 };
 
 /**
@@ -203,6 +213,32 @@ public:
         }
     };
 
+    class RollbackTimeLimitHolder {
+    public:
+        /**
+         * Returns the maximum amount of data we are willing to roll back, in seconds.
+         */
+        unsigned long long getRollbackTimeLimit() const {
+            const stdx::lock_guard<stdx::mutex> lock(_rollbackTimeLimitSecsMutex);
+            return _rollbackTimeLimitSecs;
+        }
+
+        /**
+         * Set a new limit on the allowed length of the rollback period. Measured in seconds.
+         */
+        void setRollbackTimeLimit(unsigned long long newLimit) {
+            const stdx::lock_guard<stdx::mutex> lock(_rollbackTimeLimitSecsMutex);
+            _rollbackTimeLimitSecs = newLimit;
+        }
+
+    private:
+        // Guards access to the _rollbackTimeLimitSecs member variable.
+        mutable stdx::mutex _rollbackTimeLimitSecsMutex;
+
+        // We disallow rollback if the data has a larger timespan, in seconds, than this number.
+        unsigned long long _rollbackTimeLimitSecs = 1800;
+    };
+
     /**
      * Creates a RollbackImpl instance that will run the entire rollback algorithm. This is
      * called during steady state replication when we determine that we have to roll back after
@@ -313,6 +349,12 @@ private:
         OperationContext* opCtx);
 
     /**
+     * Determines whether or not we are trying to roll back too much data. Returns an
+     * UnrecoverableRollbackError if we have exceeded the limit.
+     */
+    Status _checkAgainstTimeLimit(RollBackLocalOperations::RollbackCommonPoint commonPoint);
+
+    /**
      * Finds the timestamp of the record after the common point to put into the oplog truncate
      * after point.
      */