[Gluster-devel] solutions for split brain situation

Mark Mielke mark at mark.mielke.cc
Fri Sep 18 05:49:24 UTC 2009


On 09/18/2009 01:10 AM, Anand Avati wrote:
> > From a top level - if the unlink() system call has returned success
> back to the app, then your file is assured to be deleted no matter at
> what stage any server went down.
>
> If a server is already down even before of the unlink() call was
> initiated by the app, then the file is deleted when the server comes
> back up.
>
> If a server is brough down in the middle of an unlink transaction, no
> matter at what stage of the transaction (out of the 5 stages - lock,
> journal, act, unjournal, unlock) then the file is assured to get
> deleted (if it the server went down before the 'act's tage) when the
> server comes back - provided the transaction has proceeded to
> completion on atleast one server.
>    

Good to know. Next question was: How does this compare to a file that 
appears in the backend for the first time, including mounting gluster 
for the first time against a pre-populated backing store? What's the 
logic for knowing the difference between the above, where an unlink() is 
assured, and the file never being created on the gluster mount point in 
the first place?

Cheers,
mark

-- 
Mark Mielke<mark at mielke.cc>






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