Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On Wed, Dec 14, 2005 at 07:09:47PM +0100, Lars Marowsky-Bree wrote: > On 2005-12-14T18:59:29, Christof Amelunxen <ca at ordix.de> wrote: > > > Hi all, > > > > we are currently implementing an informix dbms cluster using Linux-HA > > (1.2.3) and drbd (0.7.5) on SLES9 SP2. Everything is working perfectly > > well so far, thanks a lot for all the work that has been done. > > > > I have a question about a special situation that may be an FAQ but still I > > didnt find any answers yet: > > > > 1. NodeA (P) --- NodeB (S) # everything ok > > 2. NodeA (P) - - NodeB (S) # DRBD detects connection loss, goes WFC > > 3. NodeA (P) - - NodeB (S) # Linux-HA detects split brain, A kills B > > 4. / - - NodeB (P) # NodeB takes over, goes primary > > > > There have been writes on NodeA between step 2 and 3. These are lost after > > Linux-HA has killed A and made B primary. I know the best solution is to > > avoid this situation by any chance and we are using serial heartbeats, > > too, but what if it happens anyway? > > The writes are lost. > I thought that if you use the strictest protocol (C?) then the writes block until they are on disk at B. At which point if your db is committing transactions then the situation is equivalent to it comitting without waiting for the the local disk and you have a bigger problem ??? Regards, Paddy -- Perl 6 will give you the big knob. -- Larry Wall