1490708 - (bmo-dbi-connector-refactor) Ensure we always call DBIx::Connector->dbh before any DBI method

Status: RESOLVED FIXED

(bugzilla.mozilla.org :: Extensions, enhancement)

Description

[Dylan Hardison [:dylan] (he/him)]

So instead of:
my $dbh = Bugzilla->dbh;
we need:

Bugzilla->dbix_connector->txn_do(
retry => sub {
    my $dbh = $_;
    # code here.
});

Comment 1

[Dylan Hardison [:dylan] (he/him)]

The code didn't allow a way of doing this without a lot of work.

Instead:

the 'dbh' attribute is now a method that delegates to DBIx::Connector's dbh method.
Per the docs, ->dbh() "Returns the connection's database handle. It will use a an existing handle if there is one, if the process has not been forked or a new thread spawned, and if the database is pingable. Otherwise, it will instantiate, cache, and return a new handle."

Then there is the matter of the 'handles' on dbh.
I've used Package::Stash to insert proxy methods into the class when it is loaded.

Comment 2

[Dylan Hardison [:dylan] (he/him)]

Attachment: GitHub Pull Request

Before this patch, if the mysql server was to restart (for instance), you'd start getting errors like this:

Bugzilla->dbh->do("select 2")

Runtime error: DBD::mysql::db do failed: MySQL server has gone away [for Statement "select 2"] at (eval 697) line 17.

And those errors would stay for the life of the request, because Bugzilla->dbh is caching the real dbh (in Bugzilla->dbh->dbh).

After this patch, what happens while the server is down:

Runtime error: DBI connect('host=198.58.111.123;database=bugs_bmo','bugs',...) failed: Can't connect to MySQL server on '198.58.111.123' (111) at /vagrant/local/lib/perl5/DBIx/Connector.pm line 32.

And after the server returns:

Bugzilla->dbh->do("select 2")
# no error.