ENABLE FAST_START FAILOVER CONDITION

The ENABLE FAST_START FAILOVER CONDITION command specifies additional conditions for which a fast-start failover should be performed.

Format

ENABLE FAST_START FAILOVER CONDITION <condition>;

Command Parameters

condition

Possible values are those described in the SHOW FAST_START FAILOVER command as health conditions. The Oracle error ORA-00240 can also be named as a condition by specifying 240 as the value.

Usage Notes

  • Table 10-2 lists some examples of health conditions maintained by the database health-check facility.

  • An error is raised if the specified value is not recognized or if the condition has already been set.

  • Table 10-2 Examples of Health Conditions

    Health Condition Description
    Datafile Write Errors If fast-start failover is enabled and the Datafile Write Errors condition is specified, then a fast-start failover is initiated if write errors are encountered in any data files, including temp files, system data files, and undo files.

    "Corrupted Controlfile"

    Corrupted controlfile. This condition is enabled by default.

    "Corrupted Dictionary"

    Dictionary corruption of a critical database object. This condition is enabled by default.

    "Inaccessible Logfile"

    LGWR is unable to write to any member of a log group due to an I/O error.

    "Stuck Archiver"

    Archiver is unable to archive a redo log because device is full or unavailable.

  • You can display these configurable conditions with the SHOW FAST_START FAILOVER command.

  • Please note that ORA-240 is the only Oracle error that can be named as a condition for initiating a fast-start failover.

Command Examples

Example 1

The following example specifies that a fast-start failover should be done if a corrupted controlfile is detected.

ENABLE FAST_START FAILOVER CONDITION "Corrupted Controlfile";

Example 2

The following example specifies that a fast-start failover should be done if an ORA-00240 error is raised.

ENABLE FAST_START FAILOVER CONDITION 240;

Example 3

The following examples displays output that shows the condition Datafile Write Errors.

DGMGRL> SHOW FAST_START FAILOVER;

Fast-Start Failover: DISABLED

  Threshold:          180 seconds 
  Ping Interval: 3000 milliseconds
  Ping Retry: 0
  Active Target:      (none)
  Potential Targets:  "South_Sales"
    South_Sales    valid
  Observer:           (none)
  Lag Limit:          300 seconds
  Shutdown Primary:   TRUE
  Auto-reinstate:     TRUE
  Observer Reconnect: (none)
  Observer Override:  FALSE

Configurable Failover Conditions
  Health Conditions:
    Corrupted Controlfile          YES
    Corrupted Dictionary           YES
    Inaccessible Logfile            NO
    Stuck Archiver                  NO
    Datafile Write Errors          YES

  Oracle Error Conditions:
    ORA-240: control file enqueue held for more than %s seconds