How to failback in HDR?

My DR_AUTO is set to 0, manual. I'm able to get replication going from my primary server to my secondary. I'm able to effectively failover to my secondary, changing secondary informixserver mode to standalone, and successfully pointing users' applications (with attendant appserver/webserver config changes) to the secondary. But I haven't solved the conundrum of failback: I run simultaneous ontape archive-restore across the network from original secondary to primary. The restore completes without error, leaving the original primary in recovery mode, with original secondary in standone, multi- user mode. How do I proceed from here (manuals don't cover this exact case)? I've attempted a number of different sequences of onmode commands on both hosts, but to no avail -- replication doesn't recommence with original primary as primary and original secondary as secondary, and occasionally even crashes the secondary, leaving behind nasty flotsam of shared memory segments. I could simply bring the primary to multi-user mode after the failback restore, then execute yet another ontape archive-restore from primary back to secondary and recommence replication. But this strikes me as unnecessary since after failback restore to the original primary the two informixservers are nearly synchronized. Gotta be a better way. What are the precise steps, in sequence, for each informixserver after failback restore with primary in recovery and secondary in multi-user mode? Using IDS 11.50.FC4 on HPUX 11.23.

> My DR_AUTO is set to 0, manual. I'm able to get replication going > from my primary server to my secondary. I'm able to effectively > failover to my secondary, changing secondary informixserver mode to > standalone, and successfully pointing users' applications (with > attendant appserver/webserver config changes) to the secondary. But I > haven't solved the conundrum of failback: I run simultaneous ontape > archive-restore across the network from original secondary to > primary. The restore completes without error, leaving the original > primary in recovery mode, with original secondary in standone, multi- > user mode. How do I proceed from here (manuals don't cover this exact > case)? I've attempted a number of different sequences of onmode > commands on both hosts, but to no avail -- replication doesn't > recommence with original primary as primary and original secondary as > secondary, and occasionally even crashes the secondary, leaving behind > nasty flotsam of shared memory segments. > > I could simply bring the primary to multi-user mode after the failback > restore, then execute yet another ontape archive-restore from primary > back to secondary and recommence replication. But this strikes me as > unnecessary since after failback restore to the original primary the > two informixservers are nearly synchronized. Gotta be a better way. > > What are the precise steps, in sequence, for each informixserver after > failback restore with primary in recovery and secondary in multi-user > mode? > > Using IDS 11.50.FC4 on HPUX 11.23. Usually no need for new archives at all. Here's how we handle switchovers: 1. orig_primary to quiescent mode; roll to new log; force ckpt; shutdown 2. orig_secondary to standard/online mode << you can point the apps to this server now 3. bring orig_primary back up via "oninit -PHY" << does NOT go thru logical recovery 4. switch orig_secondary to primary mode 5. switch orig_primary to secondary mode (the "Clearing Logs" part may take a few minutes) 6. when replication is operational, you now have replication active in the *reverse* direction Perform necessary fixes / maintenance When ready to switch back: 7. orig_secondary to quiescent mode; roll to new log; force ckpt; shutdown 8. orig_primary to standard/online mode << you can point the apps to this server now 9. bring orig_secondary back up via "oninit -PHY" << does NOT go thru logical recovery 10. switch orig_primary to primary mode 11. switch orig_secondary to secondary mode (the "Clearing Logs" part may take a few minutes) 12. when replication is operational, you now have replication active in the *normal* direction A couple of keys to making this all work: -- There cannot be any checkpoints on the server that has been primary, after it loses connection to the secondary. That is why we just do the shutdown without switching the primary to standard mode. -- The special "oninit -PHY" brings up the instance to "recovery mode", i.e., physical recovery only without doing any logical recovery. HTH, Paul Mosser

Here are the documented steps - http://publib.boulder.ibm.com/infocenter/idshelp/v115/topic/com.ibm.admin.doc/ids_admin_0983.htm#ids_admin_0983 Hope this helps. Nilesh informix-list-bounces@iiug.org wrote on 01/20/2011 12:54:53 PM: > From: > > red_valsen <red_valsen@yahoo.com> > > To: > > informix-list@iiug.org > > Date: > > 01/20/2011 12:55 PM > > Subject: > > How to failback in HDR? > > Sent by: > > informix-list-bounces@iiug.org > > My DR_AUTO is set to 0, manual. I'm able to get replication going > from my primary server to my secondary. I'm able to effectively > failover to my secondary, changing secondary informixserver mode to > standalone, and successfully pointing users' applications (with > attendant appserver/webserver config changes) to the secondary. But I > haven't solved the conundrum of failback: I run simultaneous ontape > archive-restore across the network from original secondary to > primary. The restore completes without error, leaving the original > primary in recovery mode, with original secondary in standone, multi- > user mode. How do I proceed from here (manuals don't cover this exact > case)? I've attempted a number of different sequences of onmode > commands on both hosts, but to no avail -- replication doesn't > recommence with original primary as primary and original secondary as > secondary, and occasionally even crashes the secondary, leaving behind > nasty flotsam of shared memory segments. > > I could simply bring the primary to multi-user mode after the failback > restore, then execute yet another ontape archive-restore from primary > back to secondary and recommence replication. But this strikes me as > unnecessary since after failback restore to the original primary the > two informixservers are nearly synchronized. Gotta be a better way. > > What are the precise steps, in sequence, for each informixserver after > failback restore with primary in recovery and secondary in multi-user > mode? > > Using IDS 11.50.FC4 on HPUX 11.23. > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list

On Jan 20, 12:54 pm, red_valsen <red_val...@yahoo.com> wrote: > My DR_AUTO is set to 0, manual.  I'm able to get replication going > from my primary server to my secondary.  I'm able to effectively > failover to my secondary, changing secondary informixserver mode to > standalone, and successfully pointing users' applications (with > attendant appserver/webserver config changes) to the secondary.  But I > haven't solved the conundrum of failback:  I run simultaneous ontape > archive-restore across the network from original secondary to > primary.  The restore completes without error, leaving the original > primary in recovery mode, with original secondary in standone, multi- > user mode.  How do I proceed from here (manuals don't cover this exact > case)?  I've attempted a number of different sequences of onmode > commands on both hosts, but to no avail -- replication doesn't > recommence with original primary as primary and original secondary as > secondary, and occasionally even crashes the secondary, leaving behind > nasty flotsam of shared memory segments. > > I could simply bring the primary to multi-user mode after the failback > restore, then execute yet another ontape archive-restore from primary > back to secondary and recommence replication.  But this strikes me as > unnecessary since after failback restore to the original primary the > two informixservers are nearly synchronized.  Gotta be a better way. > > What are the precise steps, in sequence, for each informixserver after > failback restore with primary in recovery and secondary in multi-user > mode? > > Using IDS 11.50.FC4 on HPUX 11.23. Easiest thing to do is to put the secondary in primary mode (onmode -d make primary...). Don't do onmode -d standard as that will completly break the HDR relationship. Then when the down server is ready to come back up, bring it up as a secondary. Probably the easiest way to do this is to run "hdrmksec.sh" Later on when you want switch the roles back like they were, you can follow the process described in the admin book about swapping the primary/secondary roles.