This project will not be updated any more due to unstable base code. All the optimizations and bugfix are applied to the official iRODS 4.1.4. Please refer iRODS repository or iRODS-FUSE development repository.

iRODS-FUSE-Mod is a modified version of iRODS-FUSE (irodsFs, release 3.2) to provide better performance in file read/write and usage tracking.

Read/write performance of iRODS FUSE (irodsFs) is much slower than "iget" and "iput", which are command-line tools, when we work with large data files. This is because "iget" and "iput" use multi-threads to access remote data files and use bigger chunk size per requests while iRODS FUSE (irodsFs) uses a single thread and small chunk size.

In this modification, file read/write performances are improved by using the same techniques as "iget" and "iput" are using. While reading a remote file, the modified iRODS FUSE will download the whole file to local disk in a background. Once it finishes background downloading the file, subsequent file read is switched from a remote iRODS to a local disk and performance gets faster. When write a file, the modified iRODS FUSE will temporarily store the file content to the local disk and upload when the file is flushed. During preload and lazy-upload, the modification uses same APIs that "iget" and "iput" uses.

This modification also provides usage tracking feature. This feature is developed by Jude Nelson. This feature can be used for monitoring users or debugging purposes. Collected data will be posted to a configured remote server.

• "--preload" : use preload

• "--preload-clear-cache" : clear preload caches

• "--preload-cache-dir" : specify preload cache directory, if not specified, "/tmp/fusePreloadCache/" will be used

• "--preload-cache-max" : specify preload cache max limit (in bytes)

• "--preload-file-min" : specify minimum file size that will be preloaded (in bytes)

• "--lazyupload" : use lazy-upload

• "--lazyupload-buffer-dir" : specify lazy-upload buffer directory, if not specified, "/tmp/fuseLazyUploadBuffer/" will be used

If you just want to use the preload without configuring other parameters that relate to the preload feature, you will need to give "--preload" option. If you use any other options that relate to the preload, you don't need to give "--preload". Those options will also set "--preload" option by default.

If you just want to use the lazy-upload without configuring other parameters that relate to the lazy-upload feature, you will need to give "--lazyupload" option. If you use any other options that relate to the lazy-uploading, you don't need to give "--lazyupload". Those options will also set "--lazyupload" option by default.

Tested with iPlant Atmosphere virtual instance and iPlant DataStore(iRODS). For testing file reads, I used "cp" command to copy whole file content from fuse-mounted directory (iRODS) to local directory (local machine). For testing file writes, I used "cp" command the same but from local directory (local machine) to fuse-mounted directory (iRODS).

File Read Performance

File Write Performance

iRODS-FUSE (Unmodified)

Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:   
        91371 seconds total
        66662 seconds of transactions (0 per second)

Files:  
        9910 created (0 per second)
                Creation alone: 5000 files (0 per second)
                Mixed with transactions: 4910 files (0 per second)
        5065 read (0 per second)
        4935 appended (0 per second)
        9910 deleted (0 per second)
                Deletion alone: 4820 files (5 per second)
                Mixed with transactions: 5090 files (0 per second)

Data:   
        28158.37 megabytes read (315.57 kilobytes per second)
        57088.03 megabytes written (639.79 kilobytes per second)

iRODS-FUSE-Mod

Creating files...Done
Performing transactions..........Done
Deleting files...Done
Time:   
        58132 seconds total
        46388 seconds of transactions (0 per second)

Files:  
        9910 created (0 per second)
                Creation alone: 5000 files (0 per second)
                Mixed with transactions: 4910 files (0 per second)
        5065 read (0 per second)
        4935 appended (0 per second)
        9910 deleted (0 per second)
                Deletion alone: 4820 files (4 per second)
                Mixed with transactions: 5090 files (0 per second)

Data:   
        28158.37 megabytes read (496.01 kilobytes per second)
        57088.03 megabytes written (1005.61 kilobytes per second)

To see debug messages that iRODS FUSE (irodsFs) prints out, edit "~/.irods/.irodsEnv" file and add "irodsLogLevel" parameter. 1 means "nothing" and 9 means "many".

To activate preload and lazy-upload feature with default setting, simply type

irodsFs --preload --lazyupload /mnt/irods/

Preload creates background threads for downloading the file content to local disk. Usually these threads will still work in background even if users get a command-prompt back. For example, when a user copies only small portion of a big file from iRODS, the user will get a command-prompt back shortly. However, a background preload thread will still download the file to local disk in background for later use.

During a file is in preload, users can still open for read. Once the background preload is completed, the read will be switched to local cached file for better performance. However, users cannot open for write, modify or remove. Because this may cause cache be corrupted, those operations will return EBUSY error code (tells "system is busy"). Depends on software implementations, some softwares may return a failure message or wait until the background preload is completed.

Lazy-upload buffers file writes at local disk. Whenever a flush operation is called, this buffered writes will be transmitted to the remote iRODS server. As this lazy-upload works synchronously, file writes will be safely stored at iRODS server at flush and close. During lazy-upload, users cannot open the same file for read and write. Any operations that is related to the file will return EBUSY error code as the file is regarded as "locked".

When users try to unmount the iRODS-FUSE-MOD, if there is any background threads for preload, the unmount operation will wait until they complete the job. Forcing unmount (i.e. sudo umount -f <mount_path>) or killing the iRODS-FUSE-MOD process may create incomplete preload files. However, these incomplete preload files will be automatically removed at next execution.

When iRODS-FUSE is mounted to under user's home directory (~/mount_path), iRODS-FUSE hangs. This issue was reported by Jerry. However, as the original iRODS-FUSE has the same issue. I would not fix this issue until an official patch is released.