Avoid filling range towards the past (that'd be TS-Interval < Start)

deps/rabbitmq_management_agent/src/exometer_slide.erl

@@ -465,7 +465,7 @@ take_since([{DropTS, drop} | T], Now, Start, N, [{TS, Evt} | _] = Acc,
                                                        Interval, N)],
             take_since(Rest, Now, Start, decr(N), [E | Fill ++ Acc], Interval);
         [Prev | _] -> % next sample is out of range so needs to be filled from Start
-            Fill = [{TS1, Evt} || TS1 <- truncated_seq(Start, TS - Interval,
+            Fill = [{TS1, Evt} || TS1 <- truncated_seq(Start, max(Start, TS - Interval),
                                                        Interval, N)],
             {Prev, Fill ++ Acc}
     end;

deps/rabbitmq_management_agent/test/exometer_slide_SUITE.erl

@@ -46,7 +46,8 @@ groups() ->
                   sum_single,
                   to_normalized_list,
                   to_normalized_list_no_padding,
-                  to_list_in_the_past
+                  to_list_in_the_past,
+                  sum_mgmt_352
                  ]}
     ].
 
@@ -498,8 +499,41 @@ to_list_in_the_past(_Config) ->
     % this could happen if a node with and incorrect clock joins the cluster
     [] = exometer_slide:to_list(50, 10, S).
 
+sum_mgmt_352(_Config) ->
+    Slide = sum_mgmt_352_slide(),
+    Last = 1487689330000,
+    First = 1487689270000,
+    Incr = 5000,
+    Empty = {0},
+    Sum = exometer_slide:sum(Last, First, Incr, [Slide], Empty),
+    ct:pal("SUM is ~p~n", [Sum]),
+    ok.
+
 %% -------------------------------------------------------------------
 %% Util
 %% -------------------------------------------------------------------
 
 ele(TS, V) -> {TS, {V}}.
+
+%% -------------------------------------------------------------------
+%% Data
+%% -------------------------------------------------------------------
+sum_mgmt_352_slide() ->
+    %% Provide slide as is, from a debug session triggering mgmt-352 bug
+    {slide,610000,45,122,true,5000,1487689328468,1487689106834,
+     [{1487689328468,{1574200}},
+      {1487689323467,{1538800}},
+      {1487689318466,{1500800}},
+      {1487689313465,{1459138}},
+      {1487689308463,{1419200}},
+      {1487689303462,{1379600}},
+      {1487689298461,{1340000}},
+      {1487689293460,{1303400}},
+      {1487689288460,{1265600}},
+      {1487689283458,{1231400}},
+      {1487689278457,{1215800}},
+      {1487689273456,{1215200}},
+      {1487689262487,drop},
+      {1487689257486,{1205600}}],
+     [],
+     {1591000}}.