Several alarms can be investigated using the home page’s Sessions pane and network packet flows, as follows:
Response Time Alarm
The Response Time alarm becomes active when the execution time of the Response Time SQL exceeds a threshold.
Response time is the full time (in milliseconds) it has taken a query (select 1, by default) to get from the application to SQL Server and back. Every time a real-time sampled interval starts (by default: 20 seconds), a query is sent and its response time value is displayed. Any value higher than 20 ms may indicate a performance issue, which should then be investigated to detect its source, identify the possible bottleneck, and take correcting measures.
The Response Time SQL is a user-defined Transact-SQL batch that can be used for indicating application response time.
To change the query used for determining response time, edit the Response time section in the Agent properties.
NOTE: Only members of the Foglight Administrator group can change the SQL query used for measuring SQL Server response time.
Packet Errors Alarm
The Packet Errors alarm becomes active when the rate at which SQL Server is encountering network packet errors exceeds a threshold.
When this alarm is fired, investigate what is causing the packet errors on the network.