Showing posts from 2016

Using Standby as an Alternate for Far Sync (12c): Limitations and Considerations

Based on Oracle 12.1
The Recommended Data Guard configuration is in Maximum Availability mode, when using Far Sync which is located near the Primary:

Primary Database à Far Sync Instance - Network input/output (I/O) is synchronous (Sync).
Far Sync Instance à Standby Database – Network I/O is asynchronous (Async).
Primary Database à Standby Database  – As an alternate (when Far Sync is not reachable), network I/O is asynchronous (Async).
Using SQLIf you do not use Data Guard Broker (dgmgrl), use the parameters specified below. ·Primary On the Primary Database Mandatory ParametersParameter Value Remarks LOG_ARCHIVE_DEST_2
point to Far Sync service Alternate log_archive_dest_3 Switches to the standby destination, after the number of failures specified in the next parameter is reached. max_failure 1 This value must be higher than 0 (infinite number of retries), but should not be too high, because the connection must fail after n attempts and fail over to the next destination, specified in …

Drop/remove Far-Sync Configurations from broker 12.1

Show current overall configuration
DGMGRL> show configuration

Configuration - dr

 Protection Mode: MaxAvailability

 PRMRY - Primary database
   FRSNC - Far sync instance
     STNDBY - Physical standby database

Fast-Start Failover: DISABLED

Configuration Status:
SUCCESS   (status updated 49 seconds ago)

Show current Primary redo routes settings
DGMGRL> show database PRMRY RedoRoutes  RedoRoutes = '(LOCAL : FRSNC SYNC)'

Changing to MAXPERFORMANCE to be able  to modify the RedoRoutes


Replace Primary RedoRoutes to point to Standby instead of Far Sync
DGMGRL> edit database PRMRY set property RedoRoutes='(LOCAL : STNDBY SYNC)';
Property "redoroutes" updated

Show current Standby redo routes settings
DGMGRL> show database STNDBY RedoRoutes
 RedoRoutes = '(LOCAL : FRSNC SYNC)'

Replace Standby RedoRoutes to point to Primary instead of Far Sync
DGMGRL> edit database STNDBY set prop…