[sheepdog] [PATCH 2/2] sheep: check joining nodes with newer but invalid epoch

[MORITA Kazutaka]

At Wed, 15 May 2013 01:49:18 +0900,
Hitoshi Mitake wrote:
> 
> At Wed, 15 May 2013 00:20:38 +0900,
> MORITA Kazutaka wrote:
> > 
> > From: MORITA Kazutaka <morita.kazutaka at lab.ntt.co.jp>
> > 
> > Currently, cluster_wait_for_join_check() always returns
> > CJ_RES_MASTER_TRANSFER if the joining node has a newer epoch.
> > However, we have to take into account that the node has a wrong epoch
> > (e.g. the node comes from a different cluster).
> 
> IIUC, checking the clusters which the nodes belong to is done by
> comparing ctimes. So I think master transfer is a correct behavior if
> the joining node has a larger epoch.

The joining node can have a larger epoch nubmer but a different ctime.  The
example is tests/060 in the first patch.

Thanks,

Kazutaka