Re: HDR Reconstruction (with ER :-))

Just consider the checkpoints ... they MUST be identical. As soon as they are "independent" HDR will refuse sync up On Thursday, November 22, 2012 9:39:21 AM UTC, Keith Simmons wrote: > Hi all > > I am going to raise a case for this query but wanted to get some community > > feedback/thoughts. > > Following on from a previous thread, I have an HDR pair acting as the group > > source for a source/target installation of ER (to a different IDS version on a > > different OS). > > I can see why ER should be suspended if HDR fails to confirm updates on > > the secondary (a nuisance but understandable). What is of more concern is > > f one of the HDR pair is unavailable for an extended length of time (more than > > a few minutes but less than the time taken to cycle the logs (currently 30 > > hours)). > > I cannot afford to have the ER target not being updated for this length of time > > so would (apparently) have no choice but to put the remaining HDR server > > into standard mode in order to get ER transactions transferring. However > > once the HDR pairing is broken like this I apparently have to re-create it by > > shipping a full archive to the secondary again, physically restoring and rolling > > in logs. This is time-consuming and expensive when the database is > > approaching 800Gb, the servers are 100 miles apart and same-day courier > > of tapes is the only sensible way. > > I've been testing the swap of the HDR servers between primary and > > secondary (using the supplied scripts hdrmkpri.sh and hdrmksec.sh) and > > have observed that during this procedure each of the servers is made > > standard. The primary is then made into primary and the secondary to > > secondary without using an archive restore but rather an undocumented > > (except in this script !!) flag for oninit. > > My thought is that, as long as both databases were originally an HDR pair, > > that logs have not cycled and neither database has required a restore, > > starting from both databases in standard mode can I switch one to primary, > > stop the other and restart using the undocumented flag (which would seem > > to force the engine into a physical restore state) and then switch it to > > secondary. > > This 'feels' like it should work but I would appreciate any thoughts. I am > > also hoping to get a test environment of this set up shortly to try this. > > Many thnaks > > Keith