[jbosscache-dev] NBST + persistent state

[Jason T. Greene]

Manik Surtani wrote:
> Hi guys
> 
> I might have found a potential flaw in the NBST impl that we have.
> 
> The way it works, transient state is written to the stream, and when 
> this is done, the tx log is flushed.  When the tx log is small, a FLUSH 
> is requested and then the remaining tx log is written.
> 
> But the flush isn't lifted here - the flush is only lifted once the 
> state transfer process is complete, and in between these 2 events is the 
> generation, streaming and storing of persistent state.  Which is 
> potentially much bigger than transient state, and could mean that the 
> flush is in place for much longer than expected.  
> 
> Any thoughts here, Jason?  Perhaps a solution would be to stream 
> persistent state before the tx log is flushed?  Could lead to wacky 
> stream multiplexing on the receiver's end though.

That is how it is already implemented:

transient state
persistent state
tx log
   - log write
   - flush
   - log write
   - end flush

--
Jason T. Greene
JBoss, a division of Red Hat