test(sessds): Fix unstable tests

apps/emqx/integration_test/emqx_persistent_session_ds_SUITE.erl

@@ -91,7 +91,7 @@ end_per_testcase(_TestCase, _Config) ->
     ok.
 
 %%------------------------------------------------------------------------------
-%% Helper fns
+%% Helper functions
 %%------------------------------------------------------------------------------
 
 cluster(#{n := N} = Opts) ->
@@ -147,9 +147,9 @@ start_client(Opts0 = #{}) ->
         proto_ver => v5,
         properties => #{'Session-Expiry-Interval' => 300}
     },
-    Opts = maps:to_list(emqx_utils_maps:deep_merge(Defaults, Opts0)),
-    ct:pal("starting client with opts:\n  ~p", [Opts]),
-    {ok, Client} = emqtt:start_link(Opts),
+    Opts = emqx_utils_maps:deep_merge(Defaults, Opts0),
+    ?tp(notice, "starting client", Opts),
+    {ok, Client} = emqtt:start_link(maps:to_list(Opts)),
     unlink(Client),
     on_exit(fun() -> catch emqtt:stop(Client) end),
     Client.
@@ -186,33 +186,6 @@ list_all_pubranges(Node) ->
 %% Testcases
 %%------------------------------------------------------------------------------
 
-t_non_persistent_session_subscription(_Config) ->
-    ClientId = atom_to_binary(?FUNCTION_NAME),
-    SubTopicFilter = <<"t/#">>,
-    ?check_trace(
-        #{timetrap => 30_000},
-        begin
-            ?tp(notice, "starting", #{}),
-            Client = start_client(#{
-                clientid => ClientId,
-                properties => #{'Session-Expiry-Interval' => 0}
-            }),
-            {ok, _} = emqtt:connect(Client),
-            ?tp(notice, "subscribing", #{}),
-            {ok, _, [?RC_GRANTED_QOS_2]} = emqtt:subscribe(Client, SubTopicFilter, qos2),
-
-            ok = emqtt:stop(Client),
-
-            ok
-        end,
-        fun(Trace) ->
-            ct:pal("trace:\n  ~p", [Trace]),
-            ?assertEqual([], ?of_kind(ds_session_subscription_added, Trace)),
-            ok
-        end
-    ),
-    ok.
-
 t_session_subscription_idempotency(Config) ->
     [Node1Spec | _] = ?config(node_specs, Config),
     [Node1] = ?config(nodes, Config),
@@ -222,7 +195,6 @@ t_session_subscription_idempotency(Config) ->
     ?check_trace(
         #{timetrap => 30_000},
         begin
-            #{timetrap => 20_000},
             ?force_ordering(
                 #{?snk_kind := persistent_session_ds_subscription_added},
                 _NEvents0 = 1,
@@ -553,14 +525,14 @@ t_session_gc(Config) ->
     ?check_trace(
         #{timetrap => 30_000},
         begin
-            ClientId0 = <<"session_gc0">>,
-            Client0 = StartClient(ClientId0, Port1, 30),
-
             ClientId1 = <<"session_gc1">>,
-            Client1 = StartClient(ClientId1, Port2, 1),
+            Client1 = StartClient(ClientId1, Port1, 30),
 
             ClientId2 = <<"session_gc2">>,
-            Client2 = StartClient(ClientId2, Port3, 1),
+            Client2 = StartClient(ClientId2, Port2, 1),
+
+            ClientId3 = <<"session_gc3">>,
+            Client3 = StartClient(ClientId3, Port3, 1),
 
             lists:foreach(
                 fun(Client) ->
@@ -570,49 +542,47 @@ t_session_gc(Config) ->
                     {ok, _} = emqtt:publish(Client, Topic, Payload, ?QOS_1),
                     ok
                 end,
-                [Client0, Client1, Client2]
+                [Client1, Client2, Client3]
             ),
 
             %% Clients are still alive; no session is garbage collected.
-            Res0 = ?block_until(
-                #{
-                    ?snk_kind := ds_session_gc,
-                    ?snk_span := {complete, _},
-                    ?snk_meta := #{node := N}
-                } when
-                    N =/= node(),
-                3 * GCInterval + 1_000
+            ?assertMatch(
+                {ok, _},
+                ?block_until(
+                    #{
+                        ?snk_kind := ds_session_gc,
+                        ?snk_span := {complete, _},
+                        ?snk_meta := #{node := N}
+                    } when N =/= node()
+                )
             ),
-            ?assertMatch({ok, _}, Res0),
-            {ok, #{?snk_meta := #{time := T0}}} = Res0,
             ?assertMatch([_, _, _], list_all_sessions(Node1), sessions),
             ?assertMatch([_, _, _], list_all_subscriptions(Node1), subscriptions),
 
             %% Now we disconnect 2 of them; only those should be GC'ed.
+
             ?assertMatch(
                 {ok, {ok, _}},
                 ?wait_async_action(
-                    emqtt:stop(Client1),
-                    #{?snk_kind := terminate},
-                    1_000
+                    emqtt:stop(Client2),
+                    #{?snk_kind := terminate}
                 )
             ),
-            ct:pal("disconnected client1"),
+            ?tp(notice, "disconnected client1", #{}),
             ?assertMatch(
                 {ok, {ok, _}},
                 ?wait_async_action(
-                    emqtt:stop(Client2),
-                    #{?snk_kind := terminate},
-                    1_000
+                    emqtt:stop(Client3),
+                    #{?snk_kind := terminate}
                 )
             ),
-            ct:pal("disconnected client2"),
+            ?tp(notice, "disconnected client2", #{}),
             ?assertMatch(
                 {ok, _},
                 ?block_until(
                     #{
                         ?snk_kind := ds_session_gc_cleaned,
-                        session_id := ClientId1
+                        session_id := ClientId2
                     }
                 )
             ),
@@ -621,11 +591,11 @@ t_session_gc(Config) ->
                 ?block_until(
                     #{
                         ?snk_kind := ds_session_gc_cleaned,
-                        session_id := ClientId2
+                        session_id := ClientId3
                     }
                 )
             ),
-            ?assertMatch([_], list_all_sessions(Node1), sessions),
+            ?assertMatch([ClientId1], list_all_sessions(Node1), sessions),
             ?assertMatch([_], list_all_subscriptions(Node1), subscriptions),
             ok
         end,

apps/emqx/src/emqx_persistent_session_ds.erl

@@ -79,7 +79,7 @@
     do_ensure_all_iterators_closed/1
 ]).
 
--export([print_session/1]).
+-export([print_session/1, seqno_diff/4]).
 
 -ifdef(TEST).
 -export([
@@ -152,8 +152,7 @@
     inflight_cnt,
     inflight_max,
     mqueue_len,
-    mqueue_dropped,
-    awaiting_rel_cnt
+    mqueue_dropped
 ]).
 
 %%
@@ -233,8 +232,8 @@ info(mqueue_dropped, _Session) ->
 %%     PacketId;
 % info(awaiting_rel, #sessmem{awaiting_rel = AwaitingRel}) ->
 %     AwaitingRel;
-info(awaiting_rel_cnt, #{s := S}) ->
-    seqno_diff(?QOS_2, ?rec, ?committed(?QOS_2), S);
+%% info(awaiting_rel_cnt, #{s := S}) ->
+%%     seqno_diff(?QOS_2, ?rec, ?committed(?QOS_2), S);
 info(awaiting_rel_max, #{props := Conf}) ->
     maps:get(max_awaiting_rel, Conf);
 info(await_rel_timeout, #{props := Conf}) ->
@@ -271,6 +270,8 @@ subscribe(
 ) ->
     case subs_lookup(TopicFilter, S0) of
         undefined ->
+            %% TODO: max subscriptions
+
             %% N.B.: we chose to update the router before adding the
             %% subscription to the session/iterator table. The
             %% reasoning for this is as follows:
@@ -511,16 +512,21 @@ replay_batch(Srs0, Session, ClientInfo) ->
 
 -spec disconnect(session(), emqx_types:conninfo()) -> {shutdown, session()}.
 disconnect(Session = #{s := S0}, ConnInfo) ->
-    OldConnInfo = emqx_persistent_session_ds_state:get_conninfo(S0),
-    NewConnInfo = maps:merge(OldConnInfo, maps:with([expiry_interval], ConnInfo)),
     S1 = emqx_persistent_session_ds_state:set_last_alive_at(now_ms(), S0),
-    S2 = emqx_persistent_session_ds_state:set_conninfo(NewConnInfo, S1),
+    S2 =
+        case ConnInfo of
+            #{expiry_interval := EI} when is_number(EI) ->
+                emqx_persistent_session_ds_state:set_expiry_interval(EI, S1);
+            _ ->
+                S1
+        end,
     S = emqx_persistent_session_ds_state:commit(S2),
     {shutdown, Session#{s => S}}.
 
 -spec terminate(Reason :: term(), session()) -> ok.
-terminate(_Reason, _Session = #{s := S}) ->
+terminate(_Reason, _Session = #{id := Id, s := S}) ->
     _ = emqx_persistent_session_ds_state:commit(S),
+    ?tp(debug, persistent_session_ds_terminate, #{id => Id}),
     ok.
 
 %%--------------------------------------------------------------------
@@ -558,7 +564,7 @@ session_open(SessionId, NewConnInfo) ->
     NowMS = now_ms(),
     case emqx_persistent_session_ds_state:open(SessionId) of
         {ok, S0} ->
-            EI = expiry_interval(emqx_persistent_session_ds_state:get_conninfo(S0)),
+            EI = emqx_persistent_session_ds_state:get_expiry_interval(S0),
             LastAliveAt = emqx_persistent_session_ds_state:get_last_alive_at(S0),
             case NowMS >= LastAliveAt + EI of
                 true ->
@@ -567,7 +573,7 @@ session_open(SessionId, NewConnInfo) ->
                 false ->
                     ?tp(open_session, #{ei => EI, now => NowMS, laa => LastAliveAt}),
                     %% New connection being established
-                    S1 = emqx_persistent_session_ds_state:set_conninfo(NewConnInfo, S0),
+                    S1 = emqx_persistent_session_ds_state:set_expiry_interval(EI, S0),
                     S2 = emqx_persistent_session_ds_state:set_last_alive_at(NowMS, S1),
                     S = emqx_persistent_session_ds_state:commit(S2),
                     Inflight = emqx_persistent_session_ds_inflight:new(
@@ -587,9 +593,10 @@ session_open(SessionId, NewConnInfo) ->
 -spec session_ensure_new(id(), emqx_types:conninfo(), emqx_session:conf()) ->
     session().
 session_ensure_new(Id, ConnInfo, Conf) ->
+    ?tp(debug, persistent_session_ds_ensure_new, #{id => Id}),
     Now = now_ms(),
     S0 = emqx_persistent_session_ds_state:create_new(Id),
-    S1 = emqx_persistent_session_ds_state:set_conninfo(ConnInfo, S0),
+    S1 = emqx_persistent_session_ds_state:set_expiry_interval(expiry_interval(ConnInfo), S0),
     S2 = bump_last_alive(S1),
     S3 = emqx_persistent_session_ds_state:set_created_at(Now, S2),
     S4 = lists:foldl(
@@ -970,8 +977,7 @@ inc_seqno(Qos, SeqNo) ->
             NextSeqno
     end.
 
-%% Note: we use the least significant bit to store the QoS. Even
-%% packet IDs are QoS1, odd packet IDs are QoS2.
+%% Note: we use the most significant bit to store the QoS.
 seqno_to_packet_id(?QOS_1, SeqNo) ->
     SeqNo band ?PACKET_ID_MASK;
 seqno_to_packet_id(?QOS_2, SeqNo) ->

apps/emqx/src/emqx_persistent_session_ds.hrl

@@ -65,4 +65,11 @@
     last_seqno_qos2 = 0 :: emqx_persistent_session_ds:seqno()
 }).
 
+%% Session metadata keys:
+-define(created_at, created_at).
+-define(last_alive_at, last_alive_at).
+-define(expiry_interval, expiry_interval).
+%% Unique integer used to create unique identities
+-define(last_id, last_id).
+
 -endif.

apps/emqx/src/emqx_persistent_session_ds_gc_worker.erl

@@ -69,7 +69,7 @@ handle_info(_Info, State) ->
     {noreply, State}.
 
 %%--------------------------------------------------------------------------------
-%% Internal fns
+%% Internal functions
 %%--------------------------------------------------------------------------------
 
 ensure_gc_timer() ->
@@ -116,22 +116,21 @@ gc_loop(MinLastAlive, It0) ->
         {[], _It} ->
             ok;
         {Sessions, It} ->
-            [
-                do_gc(SessionId, MinLastAlive, LastAliveAt, EI)
-             || {SessionId, #{last_alive_at := LastAliveAt, conninfo := #{expiry_interval := EI}}} <-
-                    Sessions
-            ],
+            [do_gc(SessionId, MinLastAlive, Metadata) || {SessionId, Metadata} <- Sessions],
             gc_loop(MinLastAlive, It)
     end.
 
-do_gc(SessionId, MinLastAlive, LastAliveAt, EI) when LastAliveAt + EI < MinLastAlive ->
-    emqx_persistent_session_ds:destroy_session(SessionId),
-    ?tp(debug, ds_session_gc_cleaned, #{
-        session_id => SessionId,
-        last_alive_at => LastAliveAt,
-        expiry_interval => EI,
-        min_last_alive => MinLastAlive
-    }),
-    ok;
-do_gc(_SessionId, _MinLastAliveAt, _LastAliveAt, _EI) ->
-    ok.
+do_gc(SessionId, MinLastAlive, Metadata) ->
+    #{?last_alive_at := LastAliveAt, ?expiry_interval := EI} = Metadata,
+    case LastAliveAt + EI < MinLastAlive of
+        true ->
+            emqx_persistent_session_ds:destroy_session(SessionId),
+            ?tp(debug, ds_session_gc_cleaned, #{
+                session_id => SessionId,
+                last_alive_at => LastAliveAt,
+                expiry_interval => EI,
+                min_last_alive => MinLastAlive
+            });
+        false ->
+            ok
+    end.

apps/emqx/src/emqx_persistent_session_ds_state.erl

@@ -29,7 +29,7 @@
 -export([open/1, create_new/1, delete/1, commit/1, format/1, print_session/1, list_sessions/0]).
 -export([get_created_at/1, set_created_at/2]).
 -export([get_last_alive_at/1, set_last_alive_at/2]).
--export([get_conninfo/1, set_conninfo/2]).
+-export([get_expiry_interval/1, set_expiry_interval/2]).
 -export([new_id/1]).
 -export([get_stream/2, put_stream/3, del_stream/2, fold_streams/3]).
 -export([get_seqno/2, put_seqno/3]).
@@ -81,18 +81,11 @@
         dirty :: #{K => dirty | del}
     }.
 
-%% Session metadata:
--define(created_at, created_at).
--define(last_alive_at, last_alive_at).
--define(conninfo, conninfo).
-%% Unique integer used to create unique identities
--define(last_id, last_id).
-
 -type metadata() ::
     #{
         ?created_at => emqx_persistent_session_ds:timestamp(),
         ?last_alive_at => emqx_persistent_session_ds:timestamp(),
-        ?conninfo => emqx_types:conninfo(),
+        ?expiry_interval => emqx_types:conninfo(),
         ?last_id => integer()
     }.
 
@@ -122,6 +115,7 @@
 -define(rank_tab, emqx_ds_session_ranks).
 -define(pmap_tables, [?stream_tab, ?seqno_tab, ?rank_tab, ?subscription_tab]).
 
+%% Enable this flag if you suspect some code breaks the sequence:
 -ifndef(CHECK_SEQNO).
 -define(set_dirty, dirty => true).
 -define(unset_dirty, dirty => false).
@@ -268,13 +262,13 @@ get_last_alive_at(Rec) ->
 set_last_alive_at(Val, Rec) ->
     set_meta(?last_alive_at, Val, Rec).
 
--spec get_conninfo(t()) -> emqx_types:conninfo() | undefined.
-get_conninfo(Rec) ->
-    get_meta(?conninfo, Rec).
+-spec get_expiry_interval(t()) -> non_neg_integer() | undefined.
+get_expiry_interval(Rec) ->
+    get_meta(?expiry_interval, Rec).
 
--spec set_conninfo(emqx_types:conninfo(), t()) -> t().
-set_conninfo(Val, Rec) ->
-    set_meta(?conninfo, Val, Rec).
+-spec set_expiry_interval(non_neg_integer(), t()) -> t().
+set_expiry_interval(Val, Rec) ->
+    set_meta(?expiry_interval, Val, Rec).
 
 -spec new_id(t()) -> {emqx_persistent_session_ds:subscription_id(), t()}.
 new_id(Rec) ->

apps/emqx/src/emqx_persistent_session_ds_stream_scheduler.erl

@@ -201,12 +201,10 @@ remove_fully_replayed_streams(S0) ->
     Groups = emqx_persistent_session_ds_state:fold_streams(
         fun({SubId, _Stream}, StreamState = #srs{rank_x = RankX, rank_y = RankY}, Acc) ->
             Key = {SubId, RankX},
-            case
-                {maps:get(Key, Acc, undefined), is_fully_replayed(CommQos1, CommQos2, StreamState)}
-            of
-                {undefined, true} ->
+            case is_fully_replayed(CommQos1, CommQos2, StreamState) of
+                true when is_map_key(Key, Acc) ->
                     Acc#{Key => {true, RankY}};
-                {_, false} ->
+                true ->
                     Acc#{Key => false};
                 _ ->
                     Acc

apps/emqx/test/emqx_persistent_session_SUITE.erl

@@ -74,6 +74,7 @@ init_per_group(persistence_enabled, Config) ->
         {emqx_config,
             "session_persistence {\n"
             "  enable = true\n"
+            "  last_alive_update_interval = 100ms\n"
             "  renew_streams_interval = 100ms\n"
             "}"},
         {persistence, ds}
@@ -534,42 +535,47 @@ t_process_dies_session_expires(Config) ->
     %% Emulate an error in the connect process,
     %% or that the node of the process goes down.
     %% A persistent session should eventually expire.
-    ConnFun = ?config(conn_fun, Config),
-    ClientId = ?config(client_id, Config),
-    Topic = ?config(topic, Config),
-    STopic = ?config(stopic, Config),
-    Payload = <<"test">>,
-    {ok, Client1} = emqtt:start_link([
-        {proto_ver, v5},
-        {clientid, ClientId},
-        {properties, #{'Session-Expiry-Interval' => 1}},
-        {clean_start, true}
-        | Config
-    ]),
-    {ok, _} = emqtt:ConnFun(Client1),
-    {ok, _, [2]} = emqtt:subscribe(Client1, STopic, qos2),
-    ok = emqtt:disconnect(Client1),
-
-    maybe_kill_connection_process(ClientId, Config),
-
-    ok = publish(Topic, Payload),
-
-    timer:sleep(2000),
-
-    {ok, Client2} = emqtt:start_link([
-        {proto_ver, v5},
-        {clientid, ClientId},
-        {properties, #{'Session-Expiry-Interval' => 30}},
-        {clean_start, false}
-        | Config
-    ]),
-    {ok, _} = emqtt:ConnFun(Client2),
-    ?assertEqual(0, client_info(session_present, Client2)),
-
-    %% We should not receive the pending message
-    ?assertEqual([], receive_messages(1)),
-
-    emqtt:disconnect(Client2).
+    ?check_trace(
+        begin
+            ConnFun = ?config(conn_fun, Config),
+            ClientId = ?config(client_id, Config),
+            Topic = ?config(topic, Config),
+            STopic = ?config(stopic, Config),
+            Payload = <<"test">>,
+            {ok, Client1} = emqtt:start_link([
+                {proto_ver, v5},
+                {clientid, ClientId},
+                {properties, #{'Session-Expiry-Interval' => 1}},
+                {clean_start, true}
+                | Config
+            ]),
+            {ok, _} = emqtt:ConnFun(Client1),
+            {ok, _, [2]} = emqtt:subscribe(Client1, STopic, qos2),
+            ok = emqtt:disconnect(Client1),
+
+            maybe_kill_connection_process(ClientId, Config),
+
+            ok = publish(Topic, Payload),
+
+            timer:sleep(1500),
+
+            {ok, Client2} = emqtt:start_link([
+                {proto_ver, v5},
+                {clientid, ClientId},
+                {properties, #{'Session-Expiry-Interval' => 30}},
+                {clean_start, false}
+                | Config
+            ]),
+            {ok, _} = emqtt:ConnFun(Client2),
+            ?assertEqual(0, client_info(session_present, Client2)),
+
+            %% We should not receive the pending message
+            ?assertEqual([], receive_messages(1)),
+
+            emqtt:disconnect(Client2)
+        end,
+        []
+    ).
 
 t_publish_while_client_is_gone_qos1(Config) ->
     %% A persistent session should receive messages in its
@@ -644,7 +650,7 @@ t_publish_many_while_client_is_gone_qos1(Config) ->
         #mqtt_msg{topic = <<"loc/1/2/42">>, payload = <<"M4">>, qos = 1},
         #mqtt_msg{topic = <<"t/42/foo">>, payload = <<"M5">>, qos = 1},
         #mqtt_msg{topic = <<"loc/3/4/5">>, payload = <<"M6">>, qos = 1},
-        #mqtt_msg{topic = <<"msg/feed/me2">>, payload = <<"M7">>, qos = 1}
+        #mqtt_msg{topic = <<"msg/feed/me">>, payload = <<"M7">>, qos = 1}
     ],
     ok = publish_many(Pubs1),
     NPubs1 = length(Pubs1),

changes/ce/feat-12251.en.md

@@ -4,4 +4,4 @@ Reduce RAM usage and frequency of database requests.
 - Introduce dirty session state to avoid frequent mria transactions
 - Introduce an intermediate buffer for the persistent messages
 - Use separate tracks of PacketIds for QoS1 and QoS2 messages
-- Limit the number of continuous ranges of infligtht messages to one per stream
+- Limit the number of continuous ranges of inflight messages to one per stream