[sr-dev] git:master: db_cluster: new module for generic database clustering

[Daniel-Constantin Mierla]

Hello,

On 3/29/12 7:33 PM, Juha Heinanen wrote:
> daniel,
>
> i gave db_cluster module a try.  i configured serial connections and it
> worked fine:  when i stopped mysql server behind the higher priority
> connection, queries started to work over the lower priority connection.
>
> there is one thing that bothers me.  when higher priority connection is
> not available, i get these kind of error to syslog even when queries
> succeed over the lower priority connection:
>
> Mar 29 20:24:52 sip /usr/sbin/sip-proxy[18966]: ERROR: db_mysql [km_dbase.c:122]: driver error on query: Can't connect to MySQL server on '192.98.102.13' (115)
> Mar 29 20:24:52 sip /usr/sbin/sip-proxy[18966]: ERROR:<core>  [db_query.c:156]: error while submitting query
>
> it would be nice if those error messages could somehow be suppressed
> when one of the connections is still operational and the queries
> actually succeed.  someone may namely run such incomplete cluster many
> hours and during that time syslog will be filled with those (confusing)
> error messages.
maybe we should introduce a log_level parameter for mysql and the other 
db modules that can be controlled via config/rpc.

On the other hand, I still have some items in to-do list for the module. 
The idea is to disable a connection if a query fails and try to 
reconnect either upon a rpc command or after some time or a number 
skipped queries. At that time the error should appear only once, at the 
moment the problem is detected, eventually repeating from time to time 
when the module tries to auto-reconnect. Other suggestions are welcome, 
of course!

Cheers,
Daniel

-- 
Daniel-Constantin Mierla
Kamailio Advanced Training, April 23-26, 2012, Berlin, Germany
http://www.asipto.com/index.php/kamailio-advanced-training/