hollow/src/main/java/com/netflix/hollow/api/producer/fs/HollowFilesystemBlobStorageCleaner.java
@Override
    public void cleanSnapshots() {
        File[] files = getFilesByType(HollowProducer.Blob.Type.SNAPSHOT.prefix);

        if(files == null || files.length <= numOfSnapshotsToKeep) {
            return;
        }

        sortByLastModified(files);

        for(int i= numOfSnapshotsToKeep; i < files.length; i++){
            File file = files[i];
            boolean deleted = file.delete();
            if(!deleted) {
                log.warning("Could not delete snapshot " + file.getPath());
            }
        }
    }
@Override
    public void cleanSnapshots() {
        File[] files = getFilesByType(HollowProducer.Blob.Type.SNAPSHOT.prefix);

        if(files == null || files.length <= numOfSnapshotsToKeep) {
            return;
        }

        sortByLastModified(files);

        for(int i= numOfSnapshotsToKeep; i < files.length; i++){
            File file = files[i];
            boolean deleted = file.delete();
            if(!deleted) {
                log.warning("Could not delete snapshot " + file.getPath());
            }
        }
    }
Cleans snapshot to keep the last 'n' snapshots. Defaults to 5.