new rlm_sql connection pool logic

[Phil Mayers]

On 10/17/2011 07:31 PM, Phil Mayers wrote:
> On 10/17/2011 06:11 PM, Arran Cudbard-Bell wrote:
>
>>
>> DEVELOPERS NOTE: From this point onwards any new modules which use a
>> pool of connections, or would benefit from a pool of connections but
>> doesn't use the connection API, will not be accepted.
>
> Can we add / will you accept a patch for opening connections in the
> background / a thread? Could be a generic per-pool option. There's some
> code in that LDAP branch I created a while back.
>
> This is particularly important for rlm_ldap; lots and lots of .ac.uk
> people have problems with FR behaviour during LDAP outages. Even setting
> net_timeout really low, you incur net_timeout on each request before
> RLM_FAIL and configurable failover can kick in.

...or some other async way I should add - I know some people were keen 
on using the "Ldap connect from FD" and managing the TCP connection 
ourselves. I think I even wrote that code too...