qatime

A small widget for maintaining atime metadata on a Qumulo cluster.

Depends on redis and rsyslog, but the included docker-compose.yml can build the appropriate containers and wire them together properly. Rsyslog needs to listen for Audit messages coming from Qumulo, and the qatime container needs an NFS mount to the Qumulo cluster with admin-level permissions.

The standard atime attribute is not exposed by the Qumulo API, nor is it updated when appropriate (e.g. file read, directory listing). It is used when we respond to a stat() call, and can be set with touch -a $timestamp $path_to_file.

This widget uses a Qumulo cluster's Audit stream of syslog messages to recognize qualifying events and set the atime appropriately.

Installation

Pull the code from this repo:

git clone https://github.com/mabott/qatime.git

Set up the configuration for your environment by copying the example configuration and edit it:

cp "qatime_config_example.ini" "qatime_config.ini"

Update docker-compose.yml to reflect the correct address of one node of your Qumulo cluster:

volumes:
  qumulo:
    driver: local
    driver_opts:
      type: nfs
      o: "addr=***,nfsvers=3,tcp,nolock,rw,hard,noac,lookupcache=none"
      device: ":/"

Mount the Qumulo cluster to the path you specified in the configuration, for the example one this is:

$ sudo mkdir -p /mnt/qumulo
$ sudo mount -t nfs -o tcp,rw,nfsvers=3,hard,intr,noac,lookupcache=none qumulo:/ /mnt/qumulo

Run the integration test:

$ python test_qatime.py

By default, this will clean up all files. Set the env var KEEP to disable this:

$ env KEEP=1 python3 test_qatime.py

If the above tests worked you should be in business. Fire up the containers:

$ docker-compose up --build

Test it out live:

(qatime) mbott@lol:/mnt/qumulo$ stat Demo | grep Access
Access: (0775/drwxrwxr-x)  Uid: ( 1000/   mbott)   Gid: ( 1000/   mbott)
Access: 2021-05-18 00:17:39.474255000 +0000
(qatime) mbott@lol:/mnt/qumulo$ ls Demo
atestfile.txt  testfile
(qatime) mbott@lol:/mnt/qumulo$ stat Demo | grep Access
Access: (0775/drwxrwxr-x)  Uid: ( 1000/   mbott)   Gid: ( 1000/   mbott)
Access: 2021-05-18 01:07:07.722120000 +0000
(qatime) mbott@lol:/mnt/qumulo$

Feel free to run docker-compose up --build -d to daemonize the service instead of letting it log to your console.

Known Issues

Redis might not be necessary anymore. The original intent was to use Redis as a database of paths and atime results. Currently it's only used as a cache.
This has not been adequately tested against interesting characters or character sets in the path names that get sent by Qumulo Audit.
This needs more testing, particularly e2e testing to validate the whole environment. It's unlikely that redis or rsyslog break with updates, given their stability, but you never know.