We just found that one of the setups was wrongly configured as MaxPerformance. Since Oracle 11.2 it is possible to increase the protection mode without restarting the primary (if going from MaxPerformance to MaxProtection you need to do in two steps, through MaxPerformance).
Here how to move from MaxPerformance to MaxAvailability in a config with DataGuard Broker (removed some lines to make it shorter):
DGMGRL> connect /
Connected.
DGMGRL> show configuration
Configuration - azores
Protection Mode: MaxPerformance
Databases:
azores_site1 - Primary database
azores_site2 - (*) Physical standby database
Fast-Start Failover: ENABLED
Configuration Status:
SUCCESS
DGMGRL> EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;
Error: ORA-16654: fast-start failover is enabled
Failed.
DGMGRL> stop observer
Done.
DGMGRL> show configuration
Configuration - azores
Protection Mode: MaxPerformance
Databases:
azores_site1 - Primary database
Warning: ORA-16819: fast-start failover observer not started
azores_site2 - (*) Physical standby database
Warning: ORA-16819: fast-start failover observer not started
Fast-Start Failover: ENABLED
Configuration Status:
WARNING
DGMGRL> DISABLE FAST_START FAILOVER
Disabled.
DGMGRL> show configuration
Configuration - azores
Protection Mode: MaxPerformance
Databases:
azores_site1 - Primary database
azores_site2 - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
SUCCESS
DGMGRL> EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;
Error: ORA-16627: operation disallowed since no standby databases would remain to support protection mode
Failed.
DGMGRL> show database verbose azores_site1
Database - azores_site1
Role: PRIMARY
Intended State: TRANSPORT-ON
Instance(s):
azores
Properties:
DGConnectIdentifier = 'azores_site1.portugal'
ObserverConnectIdentifier = ''
LogXptMode = 'async'
...
Database Status:
SUCCESS
DGMGRL> show database verbose azores_site2
Database - azores_site2
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 2 seconds ago)
Apply Lag: 0 seconds (computed 2 seconds ago)
Apply Rate: 1.84 MByte/s
Real Time Query: OFF
Instance(s):
azores
Properties:
DGConnectIdentifier = 'azores_site2.portugal'
ObserverConnectIdentifier = ''
LogXptMode = 'async'
...
Database Status:
SUCCESS
DGMGRL> edit database azores_site2 set state=APPLY-OFF;
Succeeded.
DGMGRL> edit database azores_site2 set property LogXptMode='SYNC';
Property "logxptmode" updated
DGMGRL> edit database azores_site1 set property LogXptMode='SYNC';
Property "logxptmode" updated
DGMGRL> EDIT CONFIGURATION SET PROTECTION MODE AS MAXAVAILABILITY;
Succeeded.
DGMGRL> show configuration;
Configuration - azores
Protection Mode: MaxAvailability
Databases:
azores_site1 - Primary database
azores_site2 - Physical standby database
Fast-Start Failover: DISABLED
Configuration Status:
SUCCESS
DGMGRL> enable fast_start failover;
Enabled.
DGMGRL> edit database azores_site2 set state=APPLY-ON;
Succeeded.
DGMGRL> show database verbose azores_site2
Database - azores_site2
Role: PHYSICAL STANDBY
Intended State: APPLY-ON
Transport Lag: 0 seconds (computed 1 second ago)
Apply Lag: 0 seconds (computed 1 second ago)
Database Status:
SUCCESS
DGMGRL> show configuration;
Configuration - azores
Protection Mode: MaxAvailability
Databases:
azores_site1 - Primary database
azores_site2 - (*) Physical standby database
Fast-Start Failover: ENABLED
Configuration Status:
SUCCESS