This blog is part of the blog series named SQL Server Monitoring.
Purpose
To show the Always On performance over time.
Sources
This feature queries the DMV sys.dm_os_performance_counters which returns a row per performance counter that is in the master data table dbo.fhsmPerfmonCounters.
Report
The report has 2 clustered column charts in the upper half and a line chart in the lower half of the report.
The left clustered column charts is showing average number of bytes sent over time, and the right is showing the average number of bytes received from replicas over time.
The line chart is showing the average synchronization lag for database transactions to be hardened on the replicas in synchronous commit mode.
The calculation is based on the article “Measuring Availability Group synchronization lag” by Derik Hammer.
Model
The model for the report uses the facts [Always On synchronization lag] and [Performance statistics] and the dimensions [Date], [Time], [Database] and [Performance counter].
It is the same model that are used by the Performance statistics and Resource Governor report.
Configuration
There is no configuration for this feature.
Scheduling
The default schedule for the feature is every 5 minutes (300 seconds).
Retention
The default retention for the table dbo.fhsmPerfmonStatistics is 60 days.
