Database monitoring with ODBC sets only SQL_LOGIN_TIMEOUT as its timeout setting, so there is no timeout for any other processes except login.

MySQL and PostgreSQL ODBC driver does not support SQL_ATTR_CONNECTION_TIMEOUT is noted in the following issue.

https://support.zabbix.com/browse/ZBX-6797

So, I think it is need to add timeout handling to ODBC connection process on Zabbix side.

I have not confirmed that it is related to this, but after restarting the target host for MSSQL monitoring, the logs of the process are no longer output after the following log (DebugLevel=4) and cannot be monitored after that.

In zbx_odbc_connect() dsn:'test' user:'test' 

I suspect that the problem may have been caused by the timeout settings.

Steps to reproduce:

1. Monitoring MSSQL using the Template DB MSSQL by ODBC.
2. Item added by the discovery rule Availability groups discovery and monitored it.
3. Restart the monitored host.

Result:

Cannot be monitored, but there is no error.

Expected:
Monitoring will continue.