Re: [sr-dev] accessing database from a child forked proces

Hi Daniel, this is the way we are creating the child processes (1 manager and n workers) the problem is with the workers. the worker will call a event-route and in the script config we try to call pres_refresh_watchers and that's where we get the pa_db = NULL. as i understand from your email, if we change PROC_NOCHLDINIT and let the child_init execute for the forked process then it will also execute child_init in other modules ? it makes sense. going to try this. static int mod_child_init(int rank) { int pid; int i; fire_init_event(rank); if (rank==PROC_MAIN) { pid=fork_process(PROC_NOCHLDINIT, "AMQP Manager", 1); if (pid<0) return -1; /* error */ if(pid==0){ kz_amqp_manager_loop(0); } else { for(i=0; i < dbk_consumer_processes; i++) { pid=fork_process(PROC_NOCHLDINIT, "AMQP Consumer", 1); if (pid<0) return -1; /* error */ if(pid==0){ mod_consumer_proc(i+1); } } } } return 0; } On Mon, Sep 8, 2014 at 1:11 PM, Daniel-Constantin Mierla < miconda(a)gmail.com&gt; wrote: > Hello, > > the database connection should not be shared beween processes, because it > can bring unexpected results in may places. > > Right now, the rule is to have one connection per process, shared by all > modules in that process. > > To achieve that, at mod_init each module opens database connection and > closes it before ending the function. Then in child_init() the connection > is opened again. Another module that will have to open in child_init() will > get the same connection now. > > When you create a new process, you tell the type of child and based on > that child_init() from the other modules are executed. > > What is the function do you use for creating a new process? Maybe you can > paste it here exactly how you do it and I can see if something can be done. > > Cheers, > Daniel > > > On 03/09/14 12:09, Luis Azedo wrote: > > Hi Jason, > > thanks for the reply. > > the last 2 statements in presence module mod_init close the connection > and set pa_db to NULL. when my module main process forks the extra > processes the pa_db in presence is NULL, so when it calls > pres_refresh_watchers it fails because pa_db is NULL. > i commented these last statements in presence mod_init and i got it to > work. > > // pa_dbf.close(pa_db); > // pa_db = NULL; > > does this have any implications on how the module works ? is it ok to > merge this change ? > > Thank you > > >> >> ---------------------------------------------------------------------- >> >> Message: 1 >> Date: Sun, 31 Aug 2014 09:40:49 +0200 >> From: Jason Penton &lt;jason.penton(a)gmail.com&gt; >> To: "Kamailio (SER) - Development Mailing List" >> &lt;sr-dev(a)lists.sip-router.org&gt; >> Subject: Re: [sr-dev] accessing database from a child forked process >> Message-ID: >> < >> CALoGXNWvHhCAO91Tfa0w8W3eYQRvfV7Qkgte7dBnD+ciNr_Kpg(a)mail.gmail.com&gt; >> Content-Type: text/plain; charset="utf-8" >> >> To confirm exactly what processes are being used, maybe check the log >> file >> and take note of process id at each log event. For example you could >> check >> the process id of the messages showing you the connection is null. Then >> run >> kamcmd ps to show the process list with a description of each Kamailio >> process. That will probably point you in the correct direction. >> >> Cheers >> Jason >> >> >> On Fri, Aug 29, 2014 at 3:53 PM, Luis Azedo < >> luis.azedo(a)factorlusitano.com&gt; >> wrote: >> >> > Hi, >> > >> > i have a module that creates 1 extra process where it processes stuff >> in a >> > loop. >> > on some condition i fire a route_event with a fakemsg and its up to the >> > user of the module to take action, it tries to work like dispatcher >> module >> > or htable (mod-init) events. >> > >> > the problem that i have is that, if i call some function on some module >> > that performs a database action, the connection is null when it calls >> > use_table. >> > >> > in this case i'm making this call >> > event_route[my_module:my_event] >> > { >> > $var(my_uri) = <<result of some operations>>; >> > pres_refresh_watchers("$var(my_uri)", "dialog", 1); >> > } >> > presence module makes the call to use_table but this call fails because >> > the connection is null. presence module is working fine besides this. >> > >> > if i make this call inside event_route[dispatcher:dst-up] it works. >> > >> > i think that dispatcher fires the event inside a callback from a >> > registered timer, so, i think (may be wrong) that it comes from a >> different >> > process ? >> > >> > i wonder if i'm missing something from child_init ? need to register >> > something ? >> > >> > thanks for your help. >> > >> > >> > >> > >> > >> > >> > _______________________________________________ >> > sr-dev mailing list >> > sr-dev(a)lists.sip-router.org >> > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev >> > >> > >>