Mirror Member Journal Transfer and Dejournaling Status

When an InterSystems IRIS instance belongs to a mirror, its member type and status, journal transfer status, and dejournaling status are displayed by the Mirror Monitor and the ^MIRROR routine Status Monitor option, as described in Monitoring Mirrors.

The following tables describe the possible types and statuses displayed; the first shows statuses specific to particular member types, while the statuses in the second apply to all member types.

Type	Status	Description
Failover	Primary	Current primary.
Failover	Backup	Connected to primary as backup.
Failover	In Trouble	As primary, in a trouble state due to lost connection with the backup; see Automatic Failover Mechanics for complete information about the varying circumstances under which the primary can enter a temporary or indefinite trouble state.
Disaster Recovery	Connected	Connected to primary as async.
Read-Only Reporting	Connected	(as above)
Read-Write Reporting	Connected	(as above)
Indeterminate	Not Initialized	The member is not initialized (the mirror configuration is not yet loaded).

Status (any type)	Description
Transition	In a transitional state that will soon change when initialization or another operation completes; this status prompts processes querying a member’s status to query again shortly. When there is no operating primary, a failover member can report this status for an extended period while it retrieves and applies journal files in the process of becoming primary; if there is another failover member that is primary, the status is Synchronizing instead.
Synchronizing	Starting up or reconnecting after being stopped or disconnected, retrieving and applying journal files in order to synchronize the database and journal state before becoming Backup or Connected.
Waiting	Unable to complete an action, such as becoming Primary, Backup, or Connected; will retry indefinitely, but user intervention may be required. See messages log for details.
Stopped	Mirroring on member stopped indefinitely by user and will not start automatically; see messages log for details.
Crashed	Mirror no longer running due to unexpected condition; see messages log for details.
Error	An unexpected error occurred while fetching the member’s status.
Down	Displayed on other members for a member that is down or inaccessible.

Note:

Mirror member Type and Status can also be obtained using the $SYSTEM.Mirror.GetMemberType()Opens in a new tab and $SYSTEM.Mirror.GetMemberStatus(Opens in a new tab) methods. Some combinations of Type and Status not listed above are reported by these calls, as follows:

Not Member and Not Initialized—Instance is configured as not a mirror member.
Read-Only or Read-Write Reporting and M/N Status—Instance is an async member of several mirrors; supply the mirrorname argument to get Status for a particular mirror.

For backup and async mirror members, Journal Transfer indicates whether a mirror member has the latest journal data from the primary and, if not, how far behind journal transfer is, while Dejournaling indicates whether all of the journal data received from the primary has been dejournaled (applied to the member’s mirrored databases) and, if not, how, how far behind dejournaling is. The following tables describe the possible statuses for these fields displayed by the Mirror Monitor and ^MIRROR. (These fields are always N/A for the primary.)

Journal Transfer	Description
Active (backup only)	The backup has received the latest journal data from and is synchronized with the primary. (See in Backup Status and Automatic Failover for more information about Active backup status.) Note that the backup can be Active even if its Dejournaling status is not Caught up; as long as the backup has all the needed journal files, they can be dejournaled even after it has lost its connection to the primary.
Caught up	On the backup, indicates that the backup has received the latest journal data from the primary, but is not fully synchronized in that the primary is not waiting for it to acknowledge receipt of journal data. This status is often transient, as when the backup reconnects to the mirror. On an async, indicates that the async has received the latest journal data from and is synchronized with the primary.
time behind	The member is a specific amount of time behind the primary, with time representing the amount of time elapsed between the timestamp of the last journal block the member received and the current time.
Disconnected on time	The member was disconnected from the primary at the specified time.

As noted, Active in the Journal Transfer field indicates that the backup has received all journal data from and is synchronized with the primary, and is therefore capable of taking over from the primary during failover without contacting the primary’s ISCAgent to obtain additional journal data.

Dejournaling	Description
Caught up	All journal data received from the primary has been dejournaled (applied to the member’s mirrored databases).
time behind	Some journal data received from the primary has not yet been dejournaled, with time representing the amount of time elapsed between the timestamp of the last dejournaled journal block and the last journal block received from the primary.
Disconnected on time	The member was disconnected from the primary at the specified time.
Warning! Some databases need attention.	At least one mirrored database is not in a normal state; databases should be checked.
Warning! Dejournaling is stopped.	Dejournaling has been stopped by an operator or because of an error; see Managing Database Dejournaling.

Caught Up in the Dejournaling field for an Active backup failover member or Caught Up in both the Dejournaling field and the Journal Transfer field for an async member indicates that the member has received the most recent journal data from the primary and applied the most recent global operations contained in that data. If the member is not caught up, the amount of time elapsed since generation of the most recent journal data or writing of the most recent operation on the primary is displayed instead.

Incoming Journal Transfer Rate