killbill-memoizeit

diff --git a/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessInvoiceFactory.java b/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessInvoiceFactory.java
index 5f85d6b..3174f6d 100644
--- a/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessInvoiceFactory.java
+++ b/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessInvoiceFactory.java
@@ -65,12 +65,14 @@ import static com.ning.billing.osgi.bundles.analytics.utils.BusinessInvoiceUtils
 
 public class BusinessInvoiceFactory extends BusinessFactoryBase {
 
+    private static final int NB_THREADS = 20;
+
     private final Executor executor;
 
     public BusinessInvoiceFactory(final OSGIKillbillLogService logService,
                                   final OSGIKillbillAPI osgiKillbillAPI) {
         super(logService, osgiKillbillAPI);
-        executor = Executors.newFixedThreadPool(20);
+        executor = Executors.newFixedThreadPool(NB_THREADS);
     }
 
     /**
@@ -102,6 +104,7 @@ public class BusinessInvoiceFactory extends BusinessFactoryBase {
         }
 
         // Create the business invoice items
+        // We build them in parallel as invoice items are directly proportional to subscriptions (@see BusinessSubscriptionTransitionFactory)
         final CompletionService<BusinessInvoiceItemBaseModelDao> completionService = new ExecutorCompletionService<BusinessInvoiceItemBaseModelDao>(executor);
         final Multimap<UUID, BusinessInvoiceItemBaseModelDao> businessInvoiceItemsForInvoiceId = ArrayListMultimap.<UUID, BusinessInvoiceItemBaseModelDao>create();
         for (final InvoiceItem invoiceItem : allInvoiceItems.values()) {

diff --git a/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessSubscriptionTransitionFactory.java b/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessSubscriptionTransitionFactory.java
index 5573bbd..dfc2750 100644
--- a/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessSubscriptionTransitionFactory.java
+++ b/osgi-bundles/bundles/analytics/src/main/java/com/ning/billing/osgi/bundles/analytics/dao/factory/BusinessSubscriptionTransitionFactory.java
@@ -46,19 +46,22 @@ import com.ning.killbill.osgi.libs.killbill.OSGIKillbillLogService;
 
 public class BusinessSubscriptionTransitionFactory extends BusinessFactoryBase {
 
+    private static final int NB_THREADS = 20;
+
     private final Executor executor;
 
     public BusinessSubscriptionTransitionFactory(final OSGIKillbillLogService logService,
                                                  final OSGIKillbillAPI osgiKillbillAPI) {
         super(logService, osgiKillbillAPI);
-        executor = Executors.newFixedThreadPool(20);
+        executor = Executors.newFixedThreadPool(NB_THREADS);
     }
 
     public Collection<BusinessSubscriptionTransitionModelDao> createBusinessSubscriptionTransitions(final UUID accountId,
                                                                                                     final Long accountRecordId,
                                                                                                     final Long tenantRecordId,
                                                                                                     final CallContext context) throws AnalyticsRefreshException {
-        // We build bsts for each subscription in parallel - we don't care about the overall ordering but we do care about ordering for
+        // We build bsts for each subscription in parallel as large accounts may have 50,000+ bundles
+        // We don't care about the overall ordering but we do care about ordering for
         // a given subscription (we'd like the generated record ids to be sequential).
         final CompletionService<Collection<BusinessSubscriptionTransitionModelDao>> completionService = new ExecutorCompletionService<Collection<BusinessSubscriptionTransitionModelDao>>(executor);