[SR-Users] subscriber table reload

[Daniel-Constantin Mierla]

Hello,

On 8/12/11 9:12 AM, Klaus Darilion wrote:
>
> Am 11.08.2011 19:39, schrieb Fabian Borot:
>> thank you alex
>>
>> so that means that we can populate the subscribers table manually, so
>> that when a user is going to register the first time kamailio will look
>> the account up and get the user, passwd etc to prepare the md5
>> challenge.
> Yes
>
>> Then once the user is able to  register depending on the
>> settings for usrloc db [db_mode=0,1,2,3]  the record will be in memory
>> and/or db.
> No. The subscriber table is never cached. Every authentication request
> will cause a lookup in the database.
>
>> and if we have a huge subscribers table, since apparently kamailio wont
>> load those values in memory [only the AOR for the registered users] that
>> is not a problem at all right?
> Thus, Kamailio does not care how many subscribers are in the table.
> Regarding load, the only thing that matters is the number of
> authentication requests per time interval.
>
> You can not avoid the authentication load for INVITEs, but you can
> increase the "idle load" caused by REGISTER requests by increasing the
> expire value.
just to point some caching solution in case one wants to avoid too many 
DB lookup. htable module can be used to store the password after a 
successful authentication for a period of time. The logic will be like:

- request comes in
- get from htable the password for the user
- if password not in HT, do auth using database and load the password in 
credentials and store it in HT if auth ok
- if password in HT, do auth using variables

HT has auto-expires capabilities, so cached passwords will be deleted 
after a while and the password value will be loaded next time when is 
needed. The drawback is that when the password is changed, it may take 
up to auto-expire interval to be effective.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla -- http://www.asipto.com
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