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 Urgent help needed -- Database Mirroring

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private1010
Starting Member

15 Posts

Posted - 2008-06-20 : 00:09:00
Seek expert’s advice on database mirroring
in high safety mode when safety is full if for some reason communication between principal and mirror is broken for say 2 days then principal will keep working but in disconnected mode. When communication link will establish again then principal can see the mirror server
1. Will establish the mirroring automatically?
2. Then will it synchronise the mirror databases automatically?
3. If it will synchronise databases automatically then principal will process transaction
or wait till principal-mirror will be in synchronised state which again depends on
number of transaction need to redo on mirror?

Thanks in advance

sodeep
Master Smack Fu Yak Hacker

7174 Posts

Posted - 2008-06-20 : 08:05:02
1)Yes
2)Yes ,but good way is to stop mirror and take transaction log backup from principle server and restore in mirror server in NORECOVERY MODE
and start mirror back again.
3)Each transaction in principle server handshakes with commitb phase in mirror server before they are committed So it is better to take transaction log backup and restore then start mirroring back again.
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private1010
Starting Member

15 Posts

Posted - 2008-06-22 : 22:20:47
quote:
Originally posted by sodeep


3)Each transaction in principle server handshakes with commitb phase in mirror server before they are committed So it is better to take transaction log backup and restore then start mirroring back again.


I do understand that in synchronous mode there is 2 way commit but my confusion is if communication got broken for few days and then when it got established then principal and mirror start synchronizing while mirror trying to synchronize does Principal server will process further transaction (unlikely synchronous mode) or it will wait till mirror get synchronized.
What I assume is when principal and mirror are in disconnected state principal continue serving database requests the moment it will see the mirror will it keep doing the same or it will wait for mirror to get synchronized first.

Thanks in advance
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rmiao
Master Smack Fu Yak Hacker

7266 Posts

Posted - 2008-06-22 : 22:38:50
Should happen at same time.
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sodeep
Master Smack Fu Yak Hacker

7174 Posts

Posted - 2008-06-23 : 09:08:25
But that will cause too much tax for Principle server.
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