[Zope-CMF] backup strategies
Fri, 7 Feb 2003 20:35:38 +0000
On Friday 07 February 2003 6:59 pm, email@example.com wrote:
> Heartbeat also manages resource with init-like scripts, when the takeover
> started, it would start up a ZSS process on a replicated DirectoryStorage
> after taking over the IP. For safety, you would want to likely kill the
> primary server to keep it from replicating to the backup after the
> takeover. You could do this by using a power-device (STONITH: Shoot The
> Other Node In The Head).
STONITH shouldnt be necessary for safety if using DirectoryStorage's new
replication tool. File locking takes care of preventing a replication taking
place while the replica storage is live, and revision checking in the
replication tool will forever block replication if a write transaction
happens inside the live replica, even once the file locks have gone.
Is ClientStorage reliably safe in this context? I suspect it may be possible
for it to get confused if the replica storage comes up missing the last
couple of trasactions. I have been planning some experiments in this area.
There is an easy solution to any problem; ClientStorage needs to trigger a
full Zope shutdown and restart when it loses its connection to the ZEO
> > Is there any way for example to *test* Data.fs when you back it up (to be
> > sure that you are not backing up corrupt data)?
> there's a utility in utilities/ZODBTools/fstest.py that checks
> for errors. Run a cron job that runs this tool and mails you the
> There is also another utility, fscheck.py that gives more extensive
> reports, and IIRC is new to Zope 2.6.
And for DirectoryStorage, checkds.py