How to keep a non-cascade Standby2 up to date after running Graceful Switchover on Standby1

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Read our docs This article provides some workaround to help keep Standby2 up to date after a Graceful Switchover is performed between Primary and Standby1.


Problem Details

Problem Statement

N/A

Applicable Error Code

N/A

Affected Versions

Dbvisit Standby v8

Affected Platforms

All platforms supported by v8

 


Description

How to keep Standby2 configuration working and up to date after a Graceful Switchover is performed between Primary and Standby1.

Below configuration:

Primary: kiwi701; Oracle 12.2.0.1.0 Single instance, +ASM
Standby1: kiwi702; Oracle 12.2.0.1.0 Single instance, +ASM
Standby2: kiwi703; 12.2.0.1.0 Single instance, Filesystem
DDC1: DEV1 (for Primary -> Standby1)
DDC2: DEV2 (for Primary -> Standby2)

The 3 hosts communicate with each other

Screen_Shot_2018-09-25_at_4.21.37_PM.png

The 2 DDC's - configurations

Screen_Shot_2018-09-25_at_4.25.29_PM.png

Steps Performed
 
  1. Before clicking the "SUBMIT" button, make sure the log gap is 0. Otherwise, if there is a gap, GS will prompt you to send and apply logs to standby until they are sync.
     Note: Prior to running GS, I have disabled Dbvisit Scheduling / daemon across all servers
 
2. Run GS between Primary and Standby1.
 

Screen_Shot_2018-09-25_at_5.33.59_PM.png

Screen_Shot_2018-09-25_at_5.37.15_PM.png

3. Once GS is successful, send and apply logs should work as per normal between the new          Primary (kiwi702) and now Standby1 (kiwi701)

          On new Primary:

Screen_Shot_2018-09-25_at_5.39.41_PM.png

         On now Standby1:

Screen_Shot_2018-09-25_at_5.40.16_PM.png
  
But how do you keep the link between the new Primary (kiwi702) and Standby2 (kiwi703) to ensure send and apply of logs can still continue?
 
The following steps explain how this is accomplished:

1. Create a 3rd DDC called DEV3 with Primary as kiwi702 and Standby as kiwi703

    Note: Keep DDC2, for when the decision is made to switch back to the original Primary host.

Screen_Shot_2018-09-26_at_1.51.54_PM.png

2. On new Primary - Kiwi702, send logs

 Screen_Shot_2018-09-25_at_5.47.19_PM.png

3.  On Standby2 - Kiwi703, apply logs

Screen_Shot_2018-09-25_at_5.48.02_PM.png

Notice we've performed Steps 2 & 3 using the Command line. These steps can also be done through the GUI console.

After sending and applying the archived logs, the Log Gap report between kiwi702 and kiwi703  shows no gap.

Screen_Shot_2018-09-25_at_5.48.22_PM.png 

 We hope you find this knowledge article helpful.
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