Friday, March 13, 2009

Question With regard to Entity Beans, what happens if both my EJB

Question :Question With regard to Entity Beans, what happens if both my EJB
Server and Database crash, what will happen to unsaved changes? Is there
any transactional log file used? (EJB)

Answer :Actually, if your EJB server crashes, you will not even be able to make a
connection to the server to perform a bean lookup, as the server will no
longer be listening on the port for incoming JNDI lookup requests. You will
lose any data that wasn't committed prior to the crash. This is where you
should start looking into clustering your EJB server.
Another Answer
Hi, Any unsaved and uncommited changes are lost the moment your EJB
Server crashes. If your database also crashes, then all the saved changes
are also lost unless you have some backup or some recovery mechanism
to retrieve the data. So consider database replication and EJB Clustering
for such scenarios, though the occurence of such a thing is very very rare.
Thx, Uma All databse have the concept of log files(for exampe oracle have
redo log files concept). So if data bases crashes then on starting up they
fill look up the log files to perform all pending jobs. But is EJB crashes, It
depend upon the container how frequenlty it passivates or how frequesntly
it refreshes the data with Database.

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