Experimental Physics and
Industrial Control System

"Konrad, Martin" <[email protected]> · Fri, 10 Jun 2016 16:04:56 +0000

Hi Gennaro,
According to your requirements simple MySQL master -> slave
synchronization might be sufficient. However, keep in mind that your
file synchronization might be out of sync with MySQL if you are running
rsync periodically. Depending on you use case this might not be too big
of a deal since newly added/deleted/modified PVs might not be considered
mission critical.

Note that running rsync periodically introduces a delay. If you run
rsync every 5 minutes, data on your slave machine might be 5 minutes
old. You might want to consider using a NAS device or a cluster file
system instead. If you don't want to go that fancy, using ZFS or btrfs
send/receive would be a more efficient way of synchronizing your data
(no scan of all files on both machines required).

Also note that Archiver Appliance caches data in its internal buffers
before it gets written to disk. So far there is no good way of
synchronizing this data. To make that work one would probably need to
modify Archiver Appliance to use an in-memory store like Memcached or Redis.

Cheers,

Martin

-- 
Martin Konrad
Control System Engineer
Facility for Rare Isotope Beams
Michigan State University
640 South Shaw Lane
East Lansing, MI 48824-1321, USA
Tel. 517-908-7253
Email: [email protected]

Experimental Physics and Industrial Control System

Experimental Physics and
Industrial Control System