Fix HTTP hits dashboard graph

Bug: Issue 15342
Change-Id: Ib6afb628b8b275245e7a1d31f9c56f0df4124c55
diff --git a/dual-primary/cf-dashboard.yml b/dual-primary/cf-dashboard.yml
index 9d4e6dc..faba38f 100644
--- a/dual-primary/cf-dashboard.yml
+++ b/dual-primary/cf-dashboard.yml
@@ -237,8 +237,8 @@
                             "height": 6,
                             "properties": {
                                 "metrics": [
-                                    [ { "expression": "m1+m2", "label": "Primary 1 HTTP hits per second", "id": "e2", "region": "${AWS::Region}" } ],
-                                    [ { "expression": "m3+m4", "label": "Primary 2 HTTP hits per second", "id": "e1", "region": "${AWS::Region}" } ],
+                                    [ { "expression": "RATE(m1+m2)", "label": "Primary 1 HTTP hits per second", "id": "e2", "region": "${AWS::Region}" } ],
+                                    [ { "expression": "RATE(m3+m4)", "label": "Primary 2 HTTP hits per second", "id": "e1", "region": "${AWS::Region}" } ],
                                     [ "${MetricsCloudwatchNamespace}", "http/server/success_count_total", "InstanceId", "${Primary1InstanceId}", "Type", "count", { "id": "m2", "visible": false } ],
                                     [ "${MetricsCloudwatchNamespace}", "http/server/error_count_total", "InstanceId", "${Primary1InstanceId}", "Type", "count", { "id": "m1", "visible": false } ],
                                     [ "${MetricsCloudwatchNamespace}", "http/server/success_count_total", "InstanceId", "${Primary2InstanceId}", "Type", "count", { "id": "m3", "visible": false } ],