@Override
 public void readExternal(final ObjectInput in) throws IOException, ClassNotFoundException {
   nodeSource = in.readUTF();
   databaseName = in.readUTF();
   runId = in.readLong();
   operationSerial = in.readLong();
   mode = EXECUTION_MODE.values()[in.readByte()];
   status = STATUS.values()[in.readByte()];
 }
 @Override
 public void writeExternal(final ObjectOutput out) throws IOException {
   out.writeUTF(nodeSource);
   out.writeUTF(databaseName);
   out.writeLong(runId);
   out.writeLong(operationSerial);
   out.writeByte(mode.ordinal());
   out.writeByte(status.ordinal());
 }