buffered sql is blocking

[Alan DeKok]

On Mar 21, 2017, at 1:23 AM, Sami Jorl via Freeradius-Users <freeradius-users at lists.freeradius.org> wrote:
> 
> After switching to buffered sql I noticed FreeRadius is still blocked if I lock the sql tables. 

 Yes.  The buffered SQL feature depends on module fail-over.  If the module blocks instead, buffered SQL won't work.

> So FreeRadius doesn't accept new requests and doesn't save them to the detail file until the tables are unlocked. 

 Yes.  How, exactly is the server supposed to write to the detail file when all threads are blocked writing to SQL?

> AND all requests are timed out in NAS. 
> Isn't the whole purpose of using this module to accept requests as fast as possible even when database is busy? 

 ... when the database is *down*, or over-subscribed.  If the database is up, but unresponsive, buffered SQL won't help.

 In short, if FreeRADIUS depends on SQL, you need to be VERY sure that the SQL server is (a) up, and (b) responsive.

 No amount of poking FreeRADIUS can work around a bad database.

 Alan DeKok.