Customer noticed that one of their Foglight Oracle RAC agents executed "select 1 from dual" statement 485000 times within 20 seconds.
The Usability Response Time alarm calculates the response time in milliseconds as defined as the time it takes for a simple "select 1 from dual" when the connection is already opened, until the result gets to the client. Considering that it doesn't take into consideration the connection time, this kind of statement should roundtrip to the customer extremely quickly.
The number of executions may refer to the number of times that query has processed during the open connection, and the elapsed time may be the cumulative time spent for this query since the connection opened.
The query is executed against the monitored database based on the collection in the agent properties. Agent manager logs showed that the query runs every 1 minute, as designed.
The "select 1 from dual" query is a common Oracle query used by many applications. To isolate the query and determine how many of the executions are caused by Foglight: