Several login succeeded in SQL Server ERRORLOG file

Question

Is this normal to have in SQL Server errorlog file one login succeeded every 10-15 ms ?

Our software use ADO to access to SQL Database. ADO connection is create once while application running and closed when application closed. Is query execution add this line in log ?

The database is in simple recovery mode and autoclose off.

Examples of errorlog :

2017-05-04 18:34:23.46 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.50 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.53 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.57 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.61 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.64 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.68 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.72 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.75 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.79 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.83 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.87 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.91 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.94 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:23.98 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:24.02 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:24.05 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx] 2017-05-04 18:34:24.09 Logon Login succeeded for user 'userSQL'. Connection made using SQL Server authentication. [CLIENT: xxx.xxx.xxx.xxx]

Thanks to help me to understand if it is normal or not

Answer 1

This is perfectly normal.AFAIK, you can turn of this logging as well.please see below screenshot for details