On 21.09.2012 18:54, Mo Maison wrote: > > Thank you for this tip. > I do not feel confident with whole DB freeze, as I do not know DB size, > thus I can't estimate the time required to copy files. Also I fear > something > goes wrong and UNFREEZE is never called. > In case, is restarting the Derby server sufficient to "forget" this > frozen state ?
Yes. > Regarding my initial question : is there somewhere a file to watch > that indicates that server is fully shutdown ? > There is probably a kind of lock file that indicates that a DB is > being used ? <dbdir>/db.lock is created when a database is booted by a VM, to avoid several VMs trying to boot the same database. The derby *server* (engine) can open several databases. By by shutting down a database the corresponding lock file is removed, but the server can still be alive waiting for connections. Presently, I think the only way to portably check if the server is still alive is to try to connect to its port. Thanks, Dag > Watching server process in /proc would be ugly and not portable. > > M. Maison > > > Le 31/07/2012 22:59, José Ventura a écrit : >> I'm using the tips in this page to achieve a similar goal: >> >> http://db.apache.org/derby/docs/10.6/adminguide/cadminhubbkup75469.html >> >> Basically, instead of shutting down the server, you use a command to >> freeze the DB, then copy the files, then unfreeze the DB. The freeze >> call will block until it is safe to copy the files. >> >> On Tue, Jul 31, 2012 at 5:49 PM, Mo Maison <[email protected] >> <mailto:[email protected]>> wrote: >> >> Hello Derby users, >> >> I encounter sometimes a problem during cold backups : >> Derby is launched as a server (listening localhost only ) ; >> I stop the network server with standard command : >> java -cp ... \ >> org.apache.derby.drda.NetworkServerControl shutdown \ >> -h localhost -p 1527 >> >> Right after command has returned, I perform a tar of the >> database files. >> However, I have observed that, on a slow filesystem, somes >> files get deleted while tar is reading them. Which let me think >> that server is not fully stopped when process returns >> (and thus backup may be corrupted). >> >> Is that expected ? >> How can I be sure that everything is quiescent before performing >> the cold backup ? >> I use Derby 10.6.2 on 32 bits Linux. >> >> Thank you for your advices, >> >> M. Maison >> >> >
