dynamic_ha_SUITE: Ensure conditions for `rebalance_exactly` are met

I.e., queues are using different mirrors so that they are not all
rebalanced on the same node (the testcase expects they are spread on all
three nodes).

1 files changed, 25 insertions, 0 deletions

diff --git a/test/dynamic_ha_SUITE.erl b/test/dynamic_ha_SUITE.erl
index b1171a3f5f..4423ca80cd 100644
--- a/test/dynamic_ha_SUITE.erl
+++ b/test/dynamic_ha_SUITE.erl
@@ -600,6 +600,14 @@ rebalance_exactly(Config) ->
     rabbit_ct_broker_helpers:set_ha_policy(Config, A, <<"q.*">>, {<<"exactly">>, 2}),
     timer:sleep(1000),
 
+    %% Rebalancing happens with existing mirrors. Thus, before we
+    %% can verify it works as expected, we need the queues to be on
+    %% different mirrors.
+    %%
+    %% We only test Q3, Q4 and Q5 because the first two are expected to
+    %% stay where they are.
+    ensure_queues_are_mirrored_on_different_mirrors([Q3, Q4, Q5], A, ACh),
+
     rabbit_ct_client_helpers:publish(ACh, Q1, 5),
     rabbit_ct_client_helpers:publish(ACh, Q2, 3),
 
@@ -623,6 +631,23 @@ rebalance_exactly(Config) ->
 
     ok.
 
+ensure_queues_are_mirrored_on_different_mirrors(Queues, Master, Ch) ->
+    SNodes = [node(SPid)
+              || Q <- Queues,
+                 SPid <- proplists:get_value(slave_pids, find_queue(Q, Master))],
+    UniqueSNodes = lists:usort(SNodes),
+    case UniqueSNodes of
+        [_] ->
+            %% All passed queues are on the same mirror. Let's redeclare
+            %% one of them and test again.
+            Q = hd(Queues),
+            amqp_channel:call(Ch, #'queue.delete'{queue = Q}),
+            amqp_channel:call(Ch, #'queue.declare'{queue = Q}),
+            ensure_queues_are_mirrored_on_different_mirrors(Queues, Master, Ch);
+        _ ->
+            ok
+    end.
+
 rebalance_nodes(Config) ->
     [A, B, _] = rabbit_ct_broker_helpers:get_node_configs(Config, nodename),
     ACh = rabbit_ct_client_helpers:open_channel(Config, A),