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July 16, 2014 – Alert: Dejournaling Problem May Result in Missing Updates

InterSystems has corrected a defect that can impact data integrity. The defect is present in Caché, Ensemble, and HealthShare version 2013.1.0 and later.

This defect may cause some database modifications to be missed when journal files are applied to a database. The problem may occur on systems that are the target of data replication (via mirroring or shadowing), on systems recovering after an unplanned outage, or when databases are being restored from journal files.

The problem occurs rarely and exact circumstances are dependent on internal “race conditions” between several processes, so are not easily characterized externally. There is no way to tell if a system has been affected by this defect. However, on systems using mirroring or shadowing, the DATACHECK utility can be used to see if the destination system accurately reflects the source.

The correction for this defect is identified as HYY1943. It will be included in all future releases of Caché, Ensemble, and HealthShare. The first release to include the correction will be 2014.1.2 which will be available no later than July 31st. The correction is also available via Ad Hoc distribution from InterSystems Worldwide Response Center (WRC). If you have any questions regarding this advisory, please contact the Worldwide Response Center.