"jarquey" wrote : In the solution you suggest it will be application 
responsibility to manage the cache consistency during transfer ? I don?t see 
how to manage it ? 
  | 

The application could for example communicate with all members to stop 
modifying the cache until the state transfer (e.g. DB copy) is done. However, 
this boils down to what we already have.
There is no way around locking the entire tree until the state has been copied, 
at least not IMO.

anonymous wrote : 
  | About cache lock during transfer : 
  | Is it stupid  to imagine that  the  JbossCache coordinator will manage only 
 iterative Treecache nodes locks (for instance at Treecache root level)  
instead of a global cache lock during synchronization ? Sync time could be 
longer  but  the sync could  remain secure, allow concurrent transactions and 
avoid application unavailability. 
  | 

The problem here is that you can get inconsistencies when you lock node X to 
get its state, then unlock, but before you transfer the state, someone else 
modifies X.
I'm not sure it *cannot* be done, but it would have to result on consistent 
state snapshots.
Note that this problem will somewhat be mitigated with optimistic locking 
(scheduled for 1.2.5, Oct 2005): we will still need to lock the entire tree, 
but because there are no other locks in the tree (except when a TX commits), 
this should be okay.

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http://www.jboss.org/index.html?module=bb&op=viewtopic&p=3884399#3884399

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