Problem exists when there are multiple HDFS writers in writersMap. Each writer keeps an open hdfs handle to the file. Incase of Inactive writer(i.e. one which is not consuming any data from long period), the files are not closed and always remain in open state.
Ideally, these files should get closed and Hdfs writers removed from the WritersMap.
Implement a ClosingFilesPolicy that is based on Tick tuple intervals. At each tick tuple all Writers are checked and closed if they exist for a long time.