[SR-Users] db_cluster together with the registrar module = signal 11

[Daniel-Constantin Mierla]

Hello,

On 8/28/12 6:34 PM, Øyvind Kolbu wrote:
> On 2012-08-24 at 10:48, Øyvind Kolbu wrote:
>> First impression is that everything is working now, thanks! At least
>> registrations are getting populated in both databases from both servers. As
>> I'm out traveling I havn't yet tested calling and whether or not the
>> failover works as expected. I assume setting usrloc's db_mode to 3 is
>> recommended in this kind of setup?
>>
>> For now I'm using:
>>      modparam("db_cluster", "cluster","data2=>voip1_data2=9s9p;voip2_data2=8s9p")
>> on my voip1 machine, and the line below on the voip2 machine:
>>      modparam("db_cluster", "cluster","data2=>voip2_data2=9s9p;voip1_data2=8s9p")
>>
>> The same configuration created coredumps on both machines previously.
> Have played with usrloc and db_cluster a bit in the lab and think I found
> two bugs. I have not inspected the actual sql-commands, but this is based
> in my observations. Both sql-servers are running postgresql 9.1.4.
>
> 1) If the second server lacks an entry in the location table it will never
>     be populated, while the primary is updated. This is a major flaw if
>     the second server has been unavailable and then is back again it will
>     never contain the same information as the primary.
>
>     I think this is because usrloc issues an UPDATE for the row it read,
>     but the second server can not UPDATE an non existent row.
>
>     Deleting the entry from the primary server will issue an INSERT to both
>     databases and then they are identical again, for that row at least.
>
> 2) If the primary lacks an entry and the second already has it, it will
>     get an extra entry for that user. After a while though the stale entry
>     will be pruned.
>
>     Probably similar reason as above. usrloc finds no entries in the table
>     when reading, thus issuing INSERT.
>
> Tried setting
>
>      modparam("usrloc", "db_check_update", 1)
>
> but to no avail.

what do you mean by the last line? This should be the solution to for 
the issue.

>
> Even enabling
>
>     modparam("usrloc", "db_update_as_insert", 1)
>
> will not fix issue #1.

This parameter is for some special backends, like cassadra, that don't 
take commands similar to sql update.

Cheers,
Daniel

-- 
Daniel-Constantin Mierla - http://www.asipto.com
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Kamailio Advanced Training, Berlin, Nov 5-8, 2012 - http://asipto.com/u/kat