MSSQL: Service is unavailable

[DaLoZ]

I'm whipping up a demo of Zabbix in our environment and have some trouble monitoring a SQL server.

The error: 'MSSQL: Service is unavailable' > 'The TCP port of the MS SQL Server service is currently unavailable.'

Things we need to monitor:

• SVRDBS118 (database server itself) => Works fine with the Zabbix agent
• SVRDBS118\TST01 (database instance)
• SVRDBS118\TST02 (database instance)

I have applied the 'MSSQL by ODBC' template to the server and set the following macro's:
{$MSSQL.DSN} svrdbs118
{$MSSQL.INSTANCE} MSSQL$TST01
{$MSSQL.PORT} 57003


In the template itself I have changed

• {$MSSQL.PASSWORD}
• {$MSSQL.USER}

On the Zabbix server I installed the ODBC driver and configured the .ini-files as follows:

/ect/odbcinst.ini
[ODBC Driver 18 for SQL Server]
Description=Microsoft ODBC Driver 18 for SQL Server
Driver=/opt/microsoft/msodbcsql18/lib64/libmsodbcsql-18.0.so.1.1
UsageCount=1


/etc/odbc.ini
[svrdbs118]
Driver = ODBC Driver 18 for SQL Server
Server = SVRDBS118\TST01


The SQL server does not listen on TCP/1433 but on dedicated ports per instance and named pipes for the instances are enabled.

NMAP confirms the port 1433 is closed but the dedicated ports are open & sqlcmd confirms the credentials work.

The nature of the error has me thinking Zabbix keeps trying to connect on TCP/1433...

Any help getting me past this error and suggestions on how to monitor multiple instances are greatly appreciated

[DaLoZ]

I disabled SELinux and it started working...

sudo setenforce 0

[DaLoZ]

Strange thing is I can connect with the command below:

sqlcmd -S tcp:<servername>,<dynamic port> -U <SQL username> -P <SQL user password>

but not

sqlcmd -D -S example

with

[example]
Driver = ODBC Driver 17 for SQL Server
Server = <servername>
Port = <dynamic port>
User = <SQL username>
Password = <SQL user password>

[vladimir_lv]

Check if the DSN registered:

# odbcinst -q -s

[DaLoZ]

DSN is registered.

[user@server ~]$ odbcinst -q -s
[example]

[vladimir_lv]

I don't know if this helps you, but here is written that some problems were solved by reverting to ODBC driver version 17.

https://www.zabbix.com/forum/zabbix-help/447424-odbc-hell-when-trying-to-monitor-ms-sql-server

[DaLoZ]

Thanks I did get the DSN working changing the server like so:

[svrdbs118]
Driver = ODBC Driver 17 for SQL Server 
Server = tcp:svrdbs118,57003

However, Zabbix still thinks the port is closed... "MSSQL: Service's TCP port state" => Down (0) which is very odd since when I run the command below it returns 1 => Open

[user@server ~]$ zabbix_get -s svrdbs118 -k net.tcp.service[tcp,svrdbs118,57003]
1

[vladimir_lv]

Check connection under zabbix user

su - zabbix -c 'isql -vvv example <user> <password>' -s '/bin/bash'

is it works?

[DaLoZ]

The command works

[DaLoZ]

I disabled SELinux and it started working...

sudo setenforce 0