High Availability Guide : Administering and configuring HotStandby : Configuring HotStandby : Ensuring that Primary and Secondary parameter values are coordinated
  
Ensuring that Primary and Secondary parameter values are coordinated
Some of the HotStandby or other parameters must be the same on the Primary and Secondary servers, some must be different.
Certain parameters should be the same on both. To ensure that after a failover, the original Secondary becomes the new Primary and behaves the same as the old Primary, some of the HotStandby parameters must be set to the same values on the Primary and the Secondary. However, the usage of the same values is not an absolute requirement nor enforced by the system. If you use different values, the servers do not fail, but clients might see different behavior.
Some parameters that are not in the [HotStandby] section, but which are indirectly related, must also be the same on both the Primary and Secondary servers. For example, the Logging.DurabilityLevel parameter generally must be the same on the Primary and Secondary.
Certain parameters must be different on the Primary and Secondary servers, for example, to ensure that the servers can be uniquely identified and can talk to each other.
The following HotStandby parameters must be the same on both the Primary and Secondary:
[HotStandby]
2SafeAckPolicy
AutoPrimaryAlone
ConnectTimeout
HSBEnabled
PrimaryAlone (deprecated, but must be the same if used)
[IndexFile]
FileSpec must be compatible, which means that the number of FileSpec parameters must be the same and the sizes of the corresponding FileSpec parameters must match.
BlockSize
[Logging]
BlockSize
The following parameters must be different:
[HotStandby]
Connect
The following parameters can be the same or different, depending upon circumstances such as the disk drive configuration on the computer:
[General]
BackupDirectory
[[HotStandby]
CopyDirectory
There are also some settings of “non-HSB” parameters that affect HSB performance. For example, the Logging.DurabilityLevel parameter has a setting that you can use to optimize performance with HotStandby. See Durability and logging and see the description of Logging.DurabilityLevel in solidDB® Administrator Guide.
See also
Configuring HotStandby