Foglight with SQL repository: Transaction logs suddenly balloons at a specific time of day even though simple recovery mode is on (4299291)

Foglight with SQL repository: Transaction logs suddenly balloons at a specific time of day even though simple recovery mode is on, causing the transaction logs to fill up.  

Neither the FMS Management Server log nor the SQL Server logs report the root cause.

Engage the DBA and obtain the active SQL during the time of the issue.  

There is probably a daily scheduled expensive transaction that's impacting this site

Cause 1:

• For one event, it was the scheduled "end of day", Purge old alarms.  The rule was reactivated to help clean up old alarm data.  The alarm table was discovered to have 3 million rows.  This transactional event caused the transaction logs to fill.

Solution for Cause 1:

• Manually run a sql to purge the alarm table rows by desired date range
• Truncate the alarms table.