The NodeManager's DeletionService only supports file based DeletionTask's. This makes sense as files (and directories) have been the primary concern for clean up to date. With the addition of the Docker container runtime, addition types of DeletionTask are likely to be required, such as deletion of docker container and images. See
YARN-5366 and YARN-5670. This issue is to refactor the DeletionService to support additional DeletionTask's.