From: John Napiorkowski Date: Mon, 15 Dec 2008 22:02:19 +0000 (+0000) Subject: changes to replication so that if a replicant is offline when we do the initial conne... X-Git-Url: http://git.shadowcat.co.uk/gitweb/gitweb.cgi?a=commitdiff_plain;h=f15afa13598dd767ba9547328a31d4b98313a896;p=dbsrgits%2FDBIx-Class-Historic.git changes to replication so that if a replicant is offline when we do the initial connection (or if we need to globally reconnect later) the connection does not die. This is different from when a replicant is available just not listening, or if the replicant is too laggy. Thanks David Steinbrunner for the patch suggestions. --- diff --git a/lib/DBIx/Class/Storage/DBI/Replicated/Pool.pm b/lib/DBIx/Class/Storage/DBI/Replicated/Pool.pm index b1cdc82..a3db265 100644 --- a/lib/DBIx/Class/Storage/DBI/Replicated/Pool.pm +++ b/lib/DBIx/Class/Storage/DBI/Replicated/Pool.pm @@ -168,14 +168,31 @@ and return it. sub connect_replicant { my ($self, $schema, $connect_info) = @_; my $replicant = $self->create_replicant($schema); - - $replicant->connect_info($connect_info); - $replicant->ensure_connected; - DBIx::Class::Storage::DBI::Replicated::Replicant->meta->apply($replicant); - + $replicant->connect_info($connect_info); + $self->_safely_ensure_connected($replicant); + DBIx::Class::Storage::DBI::Replicated::Replicant->meta->apply($replicant); return $replicant; } +=head2 _safely_ensure_connected ($replicant) + +The standard ensure_connected method with throw an exception should it fail to +connect. For the master database this is desirable, but since replicants are +allowed to fail, this behavior is not desirable. This method wraps the call +to ensure_connected in an eval in order to catch any generated errors. That +way a slave to go completely offline (ie, the box itself can die) without +bringing down your entire pool of databases. + +=cut + +sub _safely_ensure_connected { + my ($self, $replicant, @args) = @_; + my $return; eval { + $return = $replicant->ensure_connected(@args); + }; + return $return; +} + =head2 connected_replicants Returns true if there are connected replicants. Actually is overloaded to @@ -248,9 +265,9 @@ sub validate_replicants { my $self = shift @_; foreach my $replicant($self->all_replicants) { if( + $self->_safely_ensure_connected($replicant) && $replicant->is_replicating && - $replicant->lag_behind_master <= $self->maximum_lag && - $replicant->ensure_connected + $replicant->lag_behind_master <= $self->maximum_lag ) { $replicant->active(1) } else { diff --git a/lib/DBIx/Class/Storage/DBI/Replicated/Replicant.pm b/lib/DBIx/Class/Storage/DBI/Replicated/Replicant.pm index d97120b..e9612f3 100644 --- a/lib/DBIx/Class/Storage/DBI/Replicated/Replicant.pm +++ b/lib/DBIx/Class/Storage/DBI/Replicated/Replicant.pm @@ -52,7 +52,7 @@ has 'active' => ( This class defines the following methods. -=head2 after: _query_start +=head2 around: _query_start advice iof the _query_start method to add more debuggin diff --git a/t/93storage_replication.t b/t/93storage_replication.t index ab2ffe4..161013b 100644 --- a/t/93storage_replication.t +++ b/t/93storage_replication.t @@ -249,6 +249,7 @@ $replicated $replicated->replicate; $replicated->schema->storage->replicants->{$replicant_names[0]}->active(1); $replicated->schema->storage->replicants->{$replicant_names[1]}->active(1); +$replicated->schema->storage->pool->validate_replicants; ## Make sure we can read the data. @@ -355,6 +356,7 @@ ok $replicated->schema->resultset('Artist')->find(2) $replicated->schema->storage->replicants->{$replicant_names[0]}->active(1); $replicated->schema->storage->replicants->{$replicant_names[1]}->active(1); +$replicated->schema->storage->pool->validate_replicants; ok $replicated->schema->resultset('Artist')->find(2) => 'Returned to replicates';