Alluxio-FUSE (Experimental)

Mount an Alluxio file system using FUSE.

This project uses jnr-fuse for FUSE on Java.

Requirements

• Linux kernel 2.6.9 or newer
• JDK 1.8 or newer
• libfuse 2.9.3 or newer (2.8.3 has been reported to also work - with some warnings)

Building

The alluxio-integration-fuse module is automatically built with Alluxio when the fuse maven profile is active. This profile is automatically activated when maven detects a JDK 8 or newer.

For compatibility, binary Alluxio distributions may ship without alluxio-fuse support. Please, rebuild your favourite Alluxio version yourself if you want to use alluxio-fuse (see Building Alluxio).

Usage

Mounting

After having configured and started the Alluxio cluster: $ bin/alluxio-fuse.sh mount <mount_point>

Note: the user running the script must own the mount point and have rw permissions on it.

Unmounting

$ bin/alluxio-fuse.sh umount

Check if running

$ bin/alluxio-fuse.sh stat

Optional

Edit bin/alluxio-fuse.sh and add your specific Alluxio client options in the ALLUXIO_JAVA_OPTS variable.

Status

Most basic operations are supported. However, due to Alluxio implicit characteristics, note that:

• Files can be written only once and only sequentially, and never modified.
• Due to the above, further open operations on the file must be O_RDONLY, or they will fail.

The project is experimental, so use it at your own risk.

Performance considerations

Due to the conjunct use of FUSE and JNR, the performance of the mounted file system is expected to be considerably worst than what you would see by using the alluxio-core-client directly.

Most of the problems come from the fact that there are several memory copies going on for each call on read or write operations, and that FUSE caps the maximum granularity of writes to 128KB. This could be probably improved by a large extent by leveraging the FUSE cache write-backs feature introduced in kernel 3.15 (not supported yet by libfuse 2.x userspace libs).