[Lustre-devel] some observations about metadata writeback cache
Alex Zhuravlev
bzzz at sun.com
Wed Mar 25 10:52:13 PDT 2009
>>>>> Oleg Drokin (OD) writes:
OD> Hello!
OD> On Mar 25, 2009, at 12:59 PM, Alex Zhuravlev wrote:
RR> Simple clients
RR> - don't participate in global epochs
>> hmm. if committed (in terms of transno) request can be reverted
>> during global recovery, then even simple client has to retain
>> request on replay list till it's stable in terms of epochs?
OD> Supposedly, server that performed the operation on behalf of the client
OD> can do this? So the simple client semantic does not change - the moment
OD> server has some stable record about hte operation, client can throw the
OD> data away (otherwise simple clients would need to know how to
OD> participate
OD> in rollback/replay even when the server the operation was sent to did
OD> not
OD> go down).
hmm. then wouldn't be simpler to do replay before global recovery and then
do global replay from server's undo logs?
--
thanks, Alex
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