Re: [PATCH] Reload SSL certificates on SIGHUP

On Wed, Jul 22, 2015 at 9:52 AM, Andreas Karlsson <andreas@proxel.se> wrote:
> On 07/02/2015 06:13 PM, Peter Eisentraut wrote:
>>
>> I think this would be a useful feature, and the implementation looks
>> sound.  But I don't like how the reload is organized.  Reinitializing
>> the context in the sighup handler, aside from questions about how much
>> work one should do in a signal handler, would cause SSL reinitialization
>> for unrelated reloads.  We have the GUC assign hook mechanism for
>> handling this sort of thing.  The trick would be that when multiple
>> SSL-related settings change, you only want to do one reinitialization.
>> You could either have the different assign hooks communicate with each
>> other somehow, or have them set a "need SSL init" flag that is checked
>> somewhere else.
>
>
> It is not enough to just add a hook to the GUCs since I would guess most
> users would expect the certificate to be reloaded if just the file has been
> replaced and no GUC was changed.

Why? It seems to me that the assign hook gets called once per process
at reload for a SIGHUP parameter even if its value is not changed, no?

> To support this we would need to also check
> the mtimes of the SSL files, would that complexity really be worth it?

Or we could reload the SSL context unconditionally once per reload
loop. I am wondering how costly that may prove to be though.
-- 
Michael