feat(metrics): timeout matrix count

lib/pact_broker/app.rb

@@ -126,6 +126,7 @@ def any?
       PactBroker::DB.validate_connection_config if configuration.validate_database_connection_config
       PactBroker::DB.set_mysql_strict_mode_if_mysql
       PactBroker::DB.connection.extension(:pagination)
+      PactBroker::DB.connection.extension(:statement_timeout)
 
       Sequel.datetime_class = DateTime
       Sequel.database_timezone = :utc # Store all dates in UTC, assume any date without a TZ is UTC

lib/pact_broker/configuration.rb

@@ -38,7 +38,8 @@ class Configuration
       :log_dir,
       :allow_missing_migration_files,
       :auto_migrate_db_data,
-      :use_rack_protection
+      :use_rack_protection,
+      :metrics_sql_statement_timeout
     ]
 
     attr_accessor :base_url, :log_dir, :database_connection, :auto_migrate_db, :auto_migrate_db_data, :allow_missing_migration_files, :example_data_seeder, :seed_example_data, :use_hal_browser, :html_pact_renderer, :use_rack_protection
@@ -57,6 +58,7 @@ class Configuration
     attr_reader :api_error_reporters
     attr_reader :custom_logger
     attr_accessor :policy_builder, :policy_scope_builder, :base_resource_class_factory
+    attr_accessor :metrics_sql_statement_timeout
 
     alias_method :policy_finder=, :policy_builder=
     alias_method :policy_scope_finder=, :policy_scope_builder=
@@ -126,6 +128,7 @@ def self.default_configuration
         PactBroker::Api::Resources::DefaultBaseResource
       }
       config.warning_error_class_names = ['Sequel::ForeignKeyConstraintViolation']
+      config.metrics_sql_statement_timeout = 30
       config
     end
 

lib/pact_broker/metrics/service.rb

@@ -1,3 +1,4 @@
+require 'pact_broker/configuration'
 require 'pact_broker/pacts/pact_publication'
 require 'pact_broker/pacts/pact_version'
 require 'pact_broker/domain/pacticipant'
@@ -66,7 +67,7 @@ def metrics
             count: PactBroker::Webhooks::Execution.count
           },
           matrix: {
-            count: PactBroker::Matrix::Row.count
+            count: matrix_count
           }
         }
       end
@@ -87,6 +88,16 @@ def verification_distribution
           order by 1"
           PactBroker::Pacts::PactPublication.db[query].all.each_with_object({}) { |row, hash| hash[row[:number_of_verifications]] = row[:pact_version_count] }
       end
+
+      def matrix_count
+        begin
+          PactBroker::Matrix::Row.db.with_statement_timeout(PactBroker.configuration.metrics_sql_statement_timeout) do
+            PactBroker::Matrix::Row.count
+          end
+        rescue Sequel::DatabaseError => e
+          -1
+        end
+      end
     end
   end
 end

lib/sequel/extensions/statement_timeout.rb

@@ -0,0 +1,22 @@
+module Sequel
+  module StatementTimeout
+    def with_statement_timeout(timeout_seconds = 20)
+      # Might not have postgres class loaded, use class name
+      if self.class.name == "Sequel::Postgres::Database"
+          # Don't want to use a transaction because this will often be a read and a transaction is unnecessary.
+          # Also, when using it for clean, want to control the transactions outside this.
+          current_statement_timeout = execute("show statement_timeout") { |r| r.first.values.first }
+          run("SET statement_timeout = '#{timeout_seconds}s'")
+          begin
+            yield
+          ensure
+            run("SET statement_timeout = '#{current_statement_timeout}'")
+          end
+      else
+        yield
+      end
+    end
+  end
+
+  Database.register_extension(:statement_timeout){|db| db.extend(StatementTimeout) }
+end