Class %SYSTEM.Mirror

abstract class %SYSTEM.Mirror extends Help

This class provides documentation for the public $SYSTEM.Mirror methods which are accessable from any namespace. These methods can be invoked either via ##class(%SYSTEM.Mirror).(< methodname >) or via $SYSTEM.Mirror.(< methodname >). Most of the public API for mirroring is in the SYS.Mirror class however that class is only accessable to programs running in %SYS.

Inventory

Parameters	Properties	Methods	Queries	Indices	ForeignKeys	Triggers
		5

Summary

Methods
Help	IsAsyncMember	IsBackup	IsMember	IsPrimary
MirrorName

Methods

• classmethod IsAsyncMember() as %Boolean

Test whether this system is connected to a primary as an async mirror member.

This reports true when this node has a data channel established to a primary mirror member as an async member. The node can be configured as an async member but this will report false if it does not have any data channels established at the time.

Return Value:
TRUE = node is currently connected to a mirror as an async member
FALSE = node is not currently connected to a mirror as an async member

• classmethod IsBackup() as %Boolean

Test whether this system is a backup mirror member.

A failover mirror member might report false for both IsPrimary and IsBackup if it is in the process of connecting or has failed to connect for some reason. IsBackup() is only true while the mirror data channel exists.

Return Value:
TRUE = node is currently connected to a mirror as a backup
FALSE = node is not currently connected to a mirror as a backup

• classmethod IsMember() as %Integer

Test whether this system is configured to join a mirror.

This method is useful when a site has code that should only be run on the Primary node when the node is a mirror member. This could be used in ^ZSTART or ^ZSTU to skip this code during startup when the node is a mirror member (startup code for mirrors should go in NotifyBecomePrimary^ZMIRROR).

This is also useful in conjunction with $SYSTEM.Mirror.IsPrimary in other code, such as code that is run periodically via the TaskManager, to skip running the code on non-primary mirror members as in
      quit:($SYSTEM.Mirror.IsMember() & '$SYSTEM.Mirror.IsPrimary())

Return Value:
      0 - Node is not configured to join a mirror
      1 - Node is configured as a failover mirror member
      2 - Node is configured as an async mirror member

• classmethod IsPrimary() as %Boolean

Test whether this system is the primary mirror member.

Return Value:
TRUE = node is the primary
FALSE = node is not the primary

• classmethod MirrorName() as %String

Returns the name of the mirror if the instance is configured as a failover mirror member or NULL if it is not.


[BASEXML] > [%SYSTEM] > [Mirror]		Private Storage