The recommended Isolation Level configuration for SQL server according to our connecting JIRA to SQL Server documentation is setting READ_COMMITTED_SNAPSHOT to ON. Failing to do this may in some scenarios have severe impact as described here JIRA is running out of database connections frequently on MS SQL Server. Currently, there is no warning from JIRA when you don't have the Isolation Level configured correctly.
Add a healthcheck function that checks that the correct isolation level is set, and gives a warning if it isn't. This could be implemented using an SQL query such as the following for instance: