[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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