On Sat, Apr 6, 2013 at 1:22 PM, 袁冬 <yuandong1222@xxxxxxxxx> wrote: > > Hi guys. > > I have a problem when reading the codes of the ceph. > > In the osd.cc, the tick method will check if the mon is timeout by > compare "now - g_conf->osd_mon_ack_timeout" with last_pg_stats_ack, if > it's timeout, then monc->reopen_session() will be called to try to > re-connect to the mon. > > The question is that, if the network has splited so that the osd will > never be able to connect to any mon, how do the PGs on the osd know > that? I think the PGs may still believe they are heathly with the > current OSDMap even the mons have already mark their osd down & out > (but couldn't tell them for the network problem), Then they continue > to sevice clients who have the same OSDMap with them. So two primary > PG may exist in the cluster at the same time which is terrible. > When OSDs communicate, they check if their OSDMaps match. If not, ODS that has newer OSDMap sends OSDMap to ODSs that have old map. To migrate a PG to new OSDs, the new OSDs need communicate with the old OSDs, so it's impossible to have two active PG primaries exist at the same time. > I want to knwon any code work with this issue or is there some wrong > with my opinion? > > Thanks for any help! > > > -- > 袁冬 > Email:yuandong1222@xxxxxxxxx > QQ:10200230 > -- > To unsubscribe from this list: send the line "unsubscribe ceph-devel" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
