sql failover

[Richard J Palmer]

Hi

I think this is where I am going wrong.

The aim is I want FR to handle the failover - We should be using the 
primary SQL server at all times UNLESS it fails.

MS SQL is set as a mirrored pair (nothing to do with FR) the 'Live' 
Server will answer queries - the backup will allow connections BUT the 
queries will fail.
IF the primary fails the backup automatically allows queries and the 
primary will not

>From https://wiki.freeradius.org/config/Fail-over
I have set


redundant {
    # try module sql1
          sql1
          # if that's down, try module sql2
          sql2
          # otherwise drop the request as
          # it's been "handled" by the "always"
          # module (see doc/rlm_always)
          handled
    }

Within the authenticate / authorise / accounting / postauth sections

The issue is the startup of the modules that is causing the issue 
given that the Database on sql2 is not available unless it is the 
'live' server

With regards to

>
>>
>> IF I use the odbc driver I can set the radius database to be blank AND 
>> set the table names to be radius..<table name> BUT If I leave the 
>> database name blank in the freetds driver I get 'rlm_sql_freetds: 
>> Server msg from "<Server Name>": severity(102), number(15), origin(1), 
>> layer(1), procedure "none": Incorrect syntax near ';'.' Which I assume 
>> is from when it is trying to select the database.
>
>   Sounds like and ODBC syntax error to me.
This is because the database is not available on the backup server - 
so the select db to radius fails. Using the unixodbc driver I can 
leave the database name to blank - and edit the table names to eg 
radius..radacct for example - but with the freetds driver if I leave 
the database name blank It seems to be trying the select anyway which 
fails - as the db name is blank. For now I have changed to using 
unixodbc.

It is totally possible I have the wrong end of the stick somewhere - 
If I have misunderstood / read this I am always happy for some 
pointers.

Richard



> --- Original message ---
> Subject: Re: sql failover
> From: Alan DeKok <aland at deployingradius.com>
> To: FreeRadius users mailing list 
> <freeradius-users at lists.freeradius.org>
> Date: Monday, 15/05/2017 1:45 PM
>
> On May 14, 2017, at 8:38 PM, Richard J Palmer <richard at merula.net> 
> wrote:
>>
>> This may be a simple question but I am a little stuck.
>>
>> We are using mssql as a backend for a radius server - this generally 
>> works fine.
>>
>> A new mirror server was recently installed and I am trying to create 
>> redundancy within freeradius - However I have a problem to which I am 
>> not sure of the answer
>>
>> I have created sql1 and sql2 One pointing to the primary server - the 
>> second to the backup
>>
>> the config loads OK etc however with the current mirror setup only one 
>> of the two SQL servers will allow the radius databases to be accessed. 
>> The other when connected gives 'Database 'radius' cannot be opened. It 
>> is in the middle of a restore.' At this point the radius server stops 
>> loading rather than using the working SQL connection.
>
>    You can set "start = 0" in the SQL module configuration.  This is 
> documented in the comments in the SQL module, for the "start" 
> configuration.
>
>    But it's generally a bad idea to have your system lie to 
> FreeRADIUS.  If you want fail-over, do it in FreeRADIUS.  *Don't* do 
> it somewhere else, and then also try to do it in FreeRADIUS.  That's a 
> recipe for disaster.
>
>    The two systems can get out of sync, and then the "redundant" 
> solution will end up causing problems instead of solving them.
>
>>
>> IF I use the odbc driver I can set the radius database to be blank AND 
>> set the table names to be radius..<table name> BUT If I leave the 
>> database name blank in the freetds driver I get 'rlm_sql_freetds: 
>> Server msg from "<Server Name>": severity(102), number(15), origin(1), 
>> layer(1), procedure "none": Incorrect syntax near ';'.'  Which I 
>> assume is from when it is trying to select the database.
>
>    Sounds like and ODBC syntax error to me.
>
>>
>> Can you confirm if there is a way to work with the current SQL setup ?
>
>    Let FreeRADIUS do fail-over if you want it to do fail-over.
>
>    Extra layers between FR and SQL just causes problems 99% of the 
> time.
>
>    Alan DeKok.
>
>
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