The Availability Group Redo Queue Size (KB) alert indicates the amount of log records from log files in KB that need redoing in the secondary replica to complete synchronization. Alert includes affected databases.
For more information on configuring alerts and setting thresholds, see Configure alerts .
Enable baseline thresholds
To enable alerting when this metric is outside its established baseline, click the Baseline Thresholds Enabled (as percentage of baseline) check box in the Alert Configuration window.
Create an alert response bundle
Create an alert response bundle with the Availability Group Redo Queue Size (KB) alert and related alerts. For additional information, see Create alert response bundles.