Hi Aron, Thanks a lot for the interest shown in supporting the issue.
This approach seems to be the most applicable to our case. If you think
you can work on it, please let we know and we can cooperate and help
with testing or supporting implementation or whatever needed.
- createSnapshot would be first thing we need, at first glance having
some 'location' argument to control directory where to write the
consistent copy
- loadFromSnapshot might be a plus - however if a consistent snapshot
for a region can be moved at ease using Unix commands, a restore from a
snapshot could be done by moving phisically the files to the desired
location.
- timer ... again, this might be handled at the client, but of course
would be a plus to configure as a timer
We might need to have control over backing up different regions either
individually, or several together e.g. in a short sequence so the backup
is of diffferent regions is roughly at the same time). We say 'roughly'
since the cache does not vary very often and/ or we could limit writes
to the cache at the application level for some time if needed to help
consistency of the snapshot.
Robustness of the snapshot creation would be the most important requirement.
in general, we should consider that the files can be large enough (we
have so far 1.5 GB of cached data - reason for caching a lot is that the
backend is a CMS - rather slow to generate web pages).
Silvano.
Aaron Smuts wrote:
The keys are not written until shutdown. I could create a method that could write them
to disk and make a copy of the datafile. It could be called "createSnapShot"
You could call it programatically. There are details to think through. Should we try to
load from a snapshot on startup? How many snapshots should we store? Could we create
these via a timer? I guess this could all be configurable.
Aaron
----- Original Message ----
From: Silvano <m...@ipsoft.it>
To: jcs-users@jakarta.apache.org
Sent: Wednesday, June 17, 2009 4:23:52 AM
Subject: Indexed Disk Cache safe copying of files
Since we have a large cache that needs significant time to be populated, we
need to be able to copy the files of the regions configured as Indexed Disk
Cache between different installations.
We believe this can be done safely if we turn off the jvm, but we would need to
copy safely the files while the jvm is running. However it seems that the key
files are written only when you turn off the jvm (at least the size changes
when we turn off the jvm, so we suspect that they are not synchronized to disk
in normal operations).
We can make sure at application level that nobody writes in the cache during
the file copy process, but is this sufficient?
Can anybody recommend a solution to this issue?
Best regards,
Silvano.
---------------------------------------------------------------------
To unsubscribe, e-mail: jcs-users-unsubscr...@jakarta.apache.org
For additional commands, e-mail: jcs-users-h...@jakarta.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: jcs-users-unsubscr...@jakarta.apache.org
For additional commands, e-mail: jcs-users-h...@jakarta.apache.org
---------------------------------------------------------------------
To unsubscribe, e-mail: jcs-users-unsubscr...@jakarta.apache.org
For additional commands, e-mail: jcs-users-h...@jakarta.apache.org
