code: func SetLocalSystemVar(name string, val string) {
  	switch name {
  	case TiDBDDLReorgWorkerCount:
  		SetDDLReorgWorkerCounter(int32(tidbOptPositiveInt32(val, DefTiDBDDLReorgWorkerCount)))
  	case TiDBDDLReorgBatchSize:
  		SetDDLReorgBatchSize(int32(tidbOptPositiveInt32(val, DefTiDBDDLReorgBatchSize)))
  	case TiDBDDLErrorCountLimit:
  		SetDDLErrorCountLimit(tidbOptInt64(val, DefTiDBDDLErrorCountLimit))
  	}
  }
docs: // SetLocalSystemVar sets values of the local variables which in "server" scope.