Suresh Thalamati wrote:
Yes. log1.dat will contain the transaction log , that is used to
redo the transactions in case of a crash. So files in the log
directory are essential to bring database to a consistent state
during the reboot after the crash and also for transaction
rollbacks ..etc.
I wonder how log1.dat is missing , have not seen any bugs regarding
this. Some how the log files are vanishing:
1) By chance , are the files in the database base log directory
(<database-name>/log) are compressed by some automatic/manual
process?
Nope, no compression here. The volume is a normal OS X volume, and
we're not doing anything special on program startup and shutdown.
It's a plain vanilla derby setup.
2) is there some automatic mechanism that is deleting the files in
the Users directory ?
Again, nothing special going on here.
3) Is some one manually deleting these files, thinking they are
just error log files ?
Nope, these errors are from my personal laptop, and I haven't touched
any of the files in the data directories. I did run a test whereby I
killed the java process that was running the application, and then
deleted log1.dat manually, and verified that this did result in the
rollback behavior we're seeing, so that's consistent.
Try running the application on different disk/location and check if
you are missing committed transactions, there also.
Yep, I'll definitely run some more test on other platforms, as well
as other OS X machines/environments.
I wonder if this has something to do with the rws/rwd issues on OS X,
mentioned in the bug DERBY-1 (http://issues.apache.org/jira/browse/
DERBY-1). Does someone know more about this bug, and whether there
might be a possibility these issues are related?
Also, should we be doing anything special on program shutdown to try
and minimize issues like this? I've seen a connection flag to tell
the database to shutdown, but it's not clear if this is actually
recommended, or only needed if you have a need to explicitly close a
database programatically.
Thanks,
Scotty
