resources

February 11, 2020 – Alert: Possible Skipped Transaction Rollback with Mirrored Database

InterSystems has corrected a defect that can result in skipping a transaction rollback. This can only occur after activation or addition of a mirrored database on a primary mirror member.

This problem exists for:

  • Caché and Ensemble 2018.1.3
  • InterSystems IRIS data platform 2019.1.1, 2019.3, and 2019.4
  • InterSystems IRIS for Health 2019.1.1, 2019.3, and 2019.4
  • HealthShare Health Connect 2019.1.1

The conditions necessary for this defect to be triggered are quite specific. All of the following must apply:

  • A database has been newly activated or added to a mirror on a primary mirror member.
  • The transaction being rolled back spans multiple journal files.
  • The transaction contains updates to the newly activated or added database.
  • The instance has not been restarted since adding or activating the database. (The instance is no longer vulnerable to the defect after a restart.)

A skipped rollback is immediately obvious as a message in the cconsole.log (Caché/Ensemble) or messages.log (InterSystems IRIS) similar to:

01/30/20-18:02:19:145 (388) 1 Skipped rolling back 1 update(s) in <current journal file> @<journal-file-address>

A subsequent message contains the starting address of the transaction that was skipped. Note, however, that this type of message can also occur under normal conditions that are not related to the defect. If there is no message of this kind, then the system has not encountered the defect.

The correction for this defect is identified as JO3158. It will be included in all future product releases. It is also available by requesting an Ad hoc distribution from the InterSystems Worldwide Response Center (WRC).

If you have any questions regarding this alert, please contact the Worldwide Response Center.