During a transaction, data is written to the log cache so that it’s ready to be written to the log file on commit, or can be rolled back if necessary. When the log cache is being flushed to disk, the SQL Server session will wait on the WriteLog wait type. If this happens all the time, it may suggest disk bottlenecks where the transaction log is stored.
WriteLog Wait Time (ms per sec)
Occurs while waiting for a log flush to complete. Common operations that cause log flushes are checkpoints and transaction commits. Metric shows the wait time (in ms) per elapsed second. For more information, see http://blogs.msdn.com/b/sqlsakthi/archive/2011/04/17/what-is-writelog-waittype-and-how-to-troubleshoot-and-fix-this-wait-in-sql-server.aspx.
The T-SQL query that will collect data
Instances to collect from
Databases to collect from
Use collected or calculated values
Check the Use a calculated rate of change between collections check box
WriteLog wait time too high
Raise an alert when the metric value goes
above the defined threshholds
Default threshold values
Note: These thresholds are intended as guideline values. If they seem too high or too low for your environment, replace them with values more suited to your server performance.
Raise an alert when the threshold is passed for