[sr-dev] git:master: modules_k/rls: Used db_begin() and db_commit() around blocks of related DB queries and updates
Peter Dunkley
peter.dunkley at crocodile-rcs.com
Fri Apr 20 17:52:09 CEST 2012
Hi,
I am just adding a new db init function (init_nopool) to the generic
_dbf data-structure now. I will implement the actual init_nopool
function just for PostgreSQL. We only need this for a small proprietary
module we have, so I don't expect anyone else to use this right away.
If I have time I will make the BEGIN/COMMIT/ROLLBACK functions API
functions next week, but I want to get the presence notifier stuff done
first.
Thanks,
Peter
On Fri, 2012-04-20 at 17:44 +0200, Daniel-Constantin Mierla wrote:
> Hello,
>
> On 4/20/12 5:18 PM, Peter Dunkley wrote:
>
> > Hi Daniel,
> >
> > How would we do the non-pooling stuff inside the module?
>
>
> it can be via new API field, like 'newinit' -- it is anyhow needed
> only in one or few places, so the other modules using the DB API will
> not change, just the db conenctors.
>
> My concern is actually about the fact that the user will have to know
> that a module requires internally new connections for same db url.
> From my point of view, the user knows that the module has to interact
> with the database and set a DB URL parameter for that.
>
> Jan Janak had also a point about the URL format, the '*' not being
> really right and safe used as part of schema.
>
> Therefore two things here:
> - do we need to specify from config whether it has to be a new
> connection or not? If it is mandatory to work properly, then it is not
> a configuration option
> - how do distinguish from asking a pooled and non-pooled connection.
> If we need non-pooled is needed to be specified via a config option,
> then we should do it according tot he URL format, otherwise, should be
> something internal, with no change in the existing DB url syntax.
>
>
> >
> > I believe BEGIN/COMMIT/ROLLBACK are standard SQL. I did a quick
> > search online before making the change and found that they seem to
> > be documented for PostgreSQL, MySQL SQLlite, and SQL Server. The
> > wrapper functions first check to see if DB_CAP_RAW_QUERY is set for
> > the database connection it the functions just return without error
> > if raw queries are not available. I would have thought it safe to
> > assume that if raw queries are supported the DB module supports SQL?
>
>
> It might be true right now, but even supporting raw_query, it may not
> have support for transactions. Raw query support can be implemented
> also for non-SQL. Relying on another generic API member to assume
> globally an existing specific feature, looks a bit odd for me.
>
> I don't know, right now it just feels that such extensions are more
> appropriate as API members and implemented inside connectors. It has
> also the benefit of being able to control better the behavior, if what
> Klaus pointed is needed, like disabling auto-reconnect.
>
> The feature is there, reworking a bit during the testing does not mean
> new features, so it is not a presure to change everything right now.
> But we should do the right decision so we don 't need to change in
> short term.
>
> Cheers,
> Daniel
>
>
>
>
> >
> > Peter
> >
> > On Fri, 2012-04-20 at 17:09 +0200, Daniel-Constantin Mierla wrote:
> >
> > > Hello,
> > >
> > > since it came back in the spotlight, I think the non-pooling flag
> > > should not be exposed to the config. The admin has usually no
> > > knowledge of modules' internals to know it has to configure with a
> > > new connection -- it should be only inside the module.
> > >
> > > Then, is BEGIN/COMMIT/ROLLBACK a standard everywhere across DB/SQL
> > > servers? Even if in SQL, the DB api is not only for them. I seems
> > > to be that these new functions should be better part of DB api and
> > > implemented inside the db modules. That allows also for
> > > temporarily disabling of reconnect when needed, Eventually, other
> > > DB (non-SQL) connectors can have custom implementation.
> > >
> > > Cheers,
> > > Daniel
> > >
> > > On 4/20/12 4:56 PM, Peter Dunkley wrote:
> > >
> > > > I'll update the RLS documentation to make that clear.
> > > >
> > > > As for the second item... The non-pooling stuff is still done
> > > > with a '*' at the start of the DB URL. The DB stuff doesn't use
> > > > the standard Kamailio URI parser so making DB pooling a proper
> > > > parameter is not as simple as I'd hoped it'd be. Also, the
> > > > parameter stuff would be in lib/srdb1 whereas the retries
> > > > parameter is in the DB modules themselves (modules/db_mysql and
> > > > modules/db_postgres), so I am not sure disabling automatic
> > > > reconnect on a per connection basis will be that simple to add.
> > > >
> > > > I think I'll leave those DB changes to someone a bit more
> > > > familiar with the modules :-)
> > > >
> > > > Thanks,
> > > >
> > > > Peter
> > > >
> > > > On Fri, 2012-04-20 at 16:24 +0200, Klaus Darilion wrote:
> > > >
> > > > > Now you should mention that auto reconnect must be disabled otherwise
> > > > > reconnect during transactions will cause inconsistencies.
> > > > >
> > > > > Probably it would be cool if automatically reconnect would be configured
> > > > > with the db_url (just as the non-pooling parameter)
> > > > >
> > > > > regards
> > > > > Klaus
> > > > >
> > > > > On 20.04.2012 15:02, Peter Dunkley wrote:
> > > > > > Module: sip-router
> > > > > > Branch: master
> > > > > > Commit: f71bdc3cbdf5acdf243217778e4159f2e6ab341d
> > > > > > URL: http://git.sip-router.org/cgi-bin/gitweb.cgi/sip-router/?a=commit;h=f71bdc3cbdf5acdf243217778e4159f2e6ab341d
> > > > > >
> > > > > > Author: Peter Dunkley<peter.dunkley at crocodile-rcs.com>
> > > > > > Committer: Peter Dunkley<peter.dunkley at crocodile-rcs.com>
> > > > > > Date: Fri Apr 20 14:00:22 2012 +0100
> > > > > >
> > > > > > modules_k/rls: Used db_begin() and db_commit() around blocks of related DB queries and updates
> > > > > >
> > > > > > - This makes these related sets of DB queries a single transaction. As Klaus
> > > > > > pointed out this if you don't do this you can get inconsistencies when using
> > > > > > multiple presence servers.
> > > > > >
> > > > > > ---
> > > > > >
> > > > > > modules_k/rls/notify.c | 12 ++++++++++++
> > > > > > modules_k/rls/resource_notify.c | 24 ++++++++++++++++++++++++
> > > > > > modules_k/rls/rls_db.c | 21 +++++++++++++++++++++
> > > > > > 3 files changed, 57 insertions(+), 0 deletions(-)
> > > > > >
> > > > > > diff --git a/modules_k/rls/notify.c b/modules_k/rls/notify.c
> > > > > > index 082fbfa..1836808 100644
> > > > > > --- a/modules_k/rls/notify.c
> > > > > > +++ b/modules_k/rls/notify.c
> > > > > > @@ -128,6 +128,12 @@ int send_full_notify(subs_t* subs, xmlNodePtr rl_node, str* rl_uri,
> > > > > > goto error;
> > > > > > }
> > > > > >
> > > > > > + if (db_begin(&rlpres_dbf, rlpres_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in BEGIN\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > +
> > > > > > if(rlpres_dbf.query(rlpres_db, query_cols, 0, query_vals, result_cols,
> > > > > > 1, n_result_cols,&str_resource_uri_col,&result )< 0)
> > > > > > {
> > > > > > @@ -257,6 +263,12 @@ int send_full_notify(subs_t* subs, xmlNodePtr rl_node, str* rl_uri,
> > > > > > goto error;
> > > > > > }
> > > > > >
> > > > > > + if (db_commit(&rlpres_dbf, rlpres_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in COMMIT\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > +
> > > > > > xmlFree(rlmi_cont->s);
> > > > > > pkg_free(rlmi_cont);
> > > > > >
> > > > > > diff --git a/modules_k/rls/resource_notify.c b/modules_k/rls/resource_notify.c
> > > > > > index 29e0b11..87ce806 100644
> > > > > > --- a/modules_k/rls/resource_notify.c
> > > > > > +++ b/modules_k/rls/resource_notify.c
> > > > > > @@ -893,6 +893,12 @@ static void timer_send_full_state_notifies(int round)
> > > > > > goto done;
> > > > > > }
> > > > > >
> > > > > > + if (db_begin(&rls_dbf, rls_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in BEGIN\n");
> > > > > > + goto done;
> > > > > > + }
> > > > > > +
> > > > > > /* Step 1: Find rls_watchers that require full-state notification */
> > > > > > if (rls_dbf.query(rls_db, query_cols, 0, query_vals, result_cols,
> > > > > > 1, n_result_cols, 0,&result)< 0)
> > > > > > @@ -912,6 +918,12 @@ static void timer_send_full_state_notifies(int round)
> > > > > > goto done;
> > > > > > }
> > > > > >
> > > > > > + if (db_commit(&rls_dbf, rls_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in COMMIT\n");
> > > > > > + goto done;
> > > > > > + }
> > > > > > +
> > > > > > /* Step 3: Full-state notify each watcher we found */
> > > > > > rows = RES_ROWS(result);
> > > > > > for (i = 0; i< RES_ROW_N(result); i++)
> > > > > > @@ -1025,6 +1037,12 @@ static void timer_send_update_notifies(int round)
> > > > > > goto done;
> > > > > > }
> > > > > >
> > > > > > + if (db_begin(&rlpres_dbf, rlpres_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in BEGIN\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > +
> > > > > > if(rlpres_dbf.query(rlpres_db, query_cols, 0, query_vals, result_cols,
> > > > > > 1, n_result_cols,&str_rlsubs_did_col,&result)< 0)
> > > > > > {
> > > > > > @@ -1042,6 +1060,12 @@ static void timer_send_update_notifies(int round)
> > > > > > goto error;
> > > > > > }
> > > > > >
> > > > > > + if (db_commit(&rlpres_dbf, rlpres_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in COMMIT\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > +
> > > > > > send_notifies(result, did_col, resource_uri_col, auth_state_col, reason_col,
> > > > > > pres_state_col, content_type_col);
> > > > > > error:
> > > > > > diff --git a/modules_k/rls/rls_db.c b/modules_k/rls/rls_db.c
> > > > > > index 6a00c21..46bda91 100644
> > > > > > --- a/modules_k/rls/rls_db.c
> > > > > > +++ b/modules_k/rls/rls_db.c
> > > > > > @@ -124,6 +124,7 @@ int delete_expired_subs_rlsdb( void )
> > > > > > int i;
> > > > > > subs_t subs;
> > > > > > str rlsubs_did = {0, 0};
> > > > > > + int transaction_started = 0;
> > > > > >
> > > > > > if(rls_db == NULL)
> > > > > > {
> > > > > > @@ -148,6 +149,13 @@ int delete_expired_subs_rlsdb( void )
> > > > > > result_cols[r_to_tag_col=n_result_cols++] =&str_to_tag_col;
> > > > > > result_cols[r_from_tag_col=n_result_cols++] =&str_from_tag_col;
> > > > > >
> > > > > > + if (db_begin(&rls_dbf, rls_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in BEGIN\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > + transaction_started = 1;
> > > > > > +
> > > > > > if(rls_dbf.query(rls_db, query_cols, query_ops, query_vals, result_cols,
> > > > > > n_query_cols, n_result_cols, 0,&result )< 0)
> > > > > > {
> > > > > > @@ -213,12 +221,25 @@ int delete_expired_subs_rlsdb( void )
> > > > > > pkg_free(rlsubs_did.s);
> > > > > > }
> > > > > >
> > > > > > + if (db_commit(&rls_dbf, rls_db)< 0)
> > > > > > + {
> > > > > > + LM_ERR("in COMMIT\n");
> > > > > > + goto error;
> > > > > > + }
> > > > > > +
> > > > > > if(result) rls_dbf.free_result(rls_db, result);
> > > > > > return 1;
> > > > > >
> > > > > > error:
> > > > > > if (result) rls_dbf.free_result(rls_db, result);
> > > > > > if (rlsubs_did.s) pkg_free(rlsubs_did.s);
> > > > > > +
> > > > > > + if (transaction_started)
> > > > > > + {
> > > > > > + if (db_commit(&rls_dbf, rls_db)< 0)
> > > > > > + LM_ERR("in COMMIT\n");
> > > > > > + }
> > > > > > +
> > > > > > return -1;
> > > > > > }
> > > > > >
> > > > > >
> > > > > >
> > > > > > _______________________________________________
> > > > > > sr-dev mailing list
> > > > > > sr-dev at lists.sip-router.org
> > > > > > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
> > > >
> > > >
> > > > --
> > > > Peter Dunkley
> > > > Technical Director
> > > > Crocodile RCS Ltd
> > > >
> > > >
> > > >
> > > > _______________________________________________
> > > > sr-dev mailing list
> > > > sr-dev at lists.sip-router.org
> > > > http://lists.sip-router.org/cgi-bin/mailman/listinfo/sr-dev
> > >
> > >
> > >
> > > --
> > > Daniel-Constantin Mierla
> > > Kamailio Advanced Training, April 23-26, 2012, Berlin, Germany
> > > http://www.asipto.com/index.php/kamailio-advanced-training/
> >
> >
> > --
> > Peter Dunkley
> > Technical Director
> > Crocodile RCS Ltd
>
>
>
> --
> Daniel-Constantin Mierla
> Kamailio Advanced Training, April 23-26, 2012, Berlin, Germany
> http://www.asipto.com/index.php/kamailio-advanced-training/
--
Peter Dunkley
Technical Director
Crocodile RCS Ltd
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