Add resiliency to bibliographic tool

app/services/alma_services.rb

@@ -167,7 +167,25 @@ def record(id)
         record_id = BerkeleyLibrary::Alma::RecordId.parse(id)
         return unless record_id
 
-        record_id.get_marc_record
+        fetch_record(record_id, id)
+      end
+
+      private
+
+      def fetch_record(record_id, id)
+        attempts = 0
+
+        begin
+          attempts += 1
+          record_id.get_marc_record
+        rescue Errno::ECONNRESET => e
+          raise if attempts >= 3
+
+          Rails.logger.warn("Retry Alma fetch #{attempts + 1}/3 for #{id}: #{e.message}")
+
+          sleep(1)
+          retry
+        end
       end
     end
   end

spec/models/host_bib_spec.rb

@@ -26,12 +26,46 @@ def marc_stub
     record
   end
 
-  context 'AlmaServices::Marc has' do
-    it 'alma marc' do
+  context 'AlmaServices::Marc' do
+    it 'has alma marc' do
       class_double(BerkeleyLibrary::Alma::RecordId, parse: record_id).as_stubbed_const
       expect(record_id).to receive(:get_marc_record).and_return('marc_stub')
       expect(AlmaServices::Marc.record(mms_id)).to eq('marc_stub')
     end
+
+    it 'retries when the connection is reset' do
+      class_double(BerkeleyLibrary::Alma::RecordId, parse: record_id).as_stubbed_const
+      allow(AlmaServices::Marc).to receive(:sleep)
+
+      attempts = 0
+
+      allow(record_id).to receive(:get_marc_record) do
+        attempts += 1
+        raise Errno::ECONNRESET if attempts == 1
+
+        'marc_stub'
+      end
+
+      expect(AlmaServices::Marc.record(mms_id)).to eq('marc_stub')
+      expect(record_id).to have_received(:get_marc_record).twice
+    end
+
+    it 'raises after exhuasting retries' do
+      class_double(BerkeleyLibrary::Alma::RecordId, parse: record_id).as_stubbed_const
+      allow(AlmaServices::Marc).to receive(:sleep)
+
+      allow(record_id)
+        .to receive(:get_marc_record)
+        .and_raise(Errno::ECONNRESET)
+
+      expect do
+        AlmaServices::Marc.record(mms_id)
+      end.to raise_error(Errno::ECONNRESET)
+
+      expect(record_id)
+        .to have_received(:get_marc_record)
+        .exactly(3).times
+    end
   end
 
   RSpec.shared_examples 'host_bib has alma marc' do |marc_status|