Replace metrics by seshat counters

Makefile

@@ -12,7 +12,8 @@ endef
 
 LOCAL_DEPS = sasl crypto
 dep_gen_batch_server = hex 0.8.6
-DEPS = gen_batch_server
+dep_seshat = git https://github.com/rabbitmq/seshat.git main
+DEPS = gen_batch_server seshat
 
 # TEST_DEPS=eunit_formatters looking_glass
 TEST_DEPS=eunit_formatters

src/osiris_counters.erl

@@ -26,47 +26,25 @@
 
 -spec init() -> ok.
 init() ->
-    _ = ets:new(?MODULE, [set, named_table, public]),
-    ok.
+    seshat_counters:new_group(osiris).
 
--spec new(name(), [atom()]) -> counters:counters_ref().
-new(Name, Fields) when is_list(Fields) ->
-    Size = length(Fields),
-    CRef = counters:new(Size, []),
-    ok = register_counter(Name, CRef, Fields),
-    CRef.
+-spec new(name(), [{Name :: atom(), Position :: non_neg_integer(),
+                    Type :: atom(), Description :: term()}]) ->
+                 counters:counters_ref().
+new(Name, Fields) ->
+    seshat_counters:new(osiris, Name, Fields).
 
 -spec fetch(name()) -> undefined | counters:counters_ref().
 fetch(Name) ->
-    case ets:lookup(?MODULE, Name) of
-        [{Name, Ref, _}] ->
-            Ref;
-        _ ->
-            undefined
-    end.
+    seshat_counters:fetch(osiris, Name).
 
 -spec delete(term()) -> ok.
 delete(Name) ->
-    true = ets:delete(?MODULE, Name),
-    ok.
+    seshat_counters:delete(osiris, Name).
 
 -spec overview() -> #{name() => #{atom() => non_neg_integer()}}.
 overview() ->
-    ets:foldl(fun({Name, Ref, Fields}, Acc) ->
-                 Size = length(Fields),
-                 Values = [counters:get(Ref, I) || I <- lists:seq(1, Size)],
-                 Counters =
-                     maps:from_list(
-                         lists:zip(Fields, Values)),
-                 Acc#{Name => Counters}
-              end,
-              #{}, ?MODULE).
-
-%% internal
-
-register_counter(Name, Ref, Size) ->
-    true = ets:insert(?MODULE, {Name, Ref, Size}),
-    ok.
+    seshat_counters:overview(osiris).
 
 -ifdef(TEST).
 

src/osiris_log.erl

@@ -52,22 +52,19 @@
 % maximum number of chunks per segment
 -define(DEFAULT_MAX_SEGMENT_SIZE_C, 256_000).
 -define(INDEX_RECORD_SIZE_B, 29).
--define(COUNTER_FIELDS,
-        [
-         %% the last offset (not chunk id) in the log (writers)
-         %% the last offset read (readers)
-         offset,
-         %% not updated for readers
-         first_offset,
-         %% number of chunks read or written
-         %% incremented even if a reader only reads the header
-         chunks,
-         %% number of segments
-         segments]).
 -define(C_OFFSET, 1).
 -define(C_FIRST_OFFSET, 2).
 -define(C_CHUNKS, 3).
 -define(C_SEGMENTS, 4).
+-define(COUNTER_FIELDS,
+        [
+         {offset, ?C_OFFSET, counter, "The last offset (not chunk id) in the log for writers. The last offset read for readers"
+         },
+         {first_offset, ?C_FIRST_OFFSET, counter, "First offset, not updated for readers"},
+         {chunks, ?C_CHUNKS, counter, "Number of chunks read or written, incremented even if a reader only reads the header"},
+         {segments, ?C_SEGMENTS, counter, "Number of segments"}
+        ]
+       ).
 
 %% Specification of the Log format.
 %%

src/osiris_replica.erl

@@ -60,11 +60,16 @@
 
 -export_type([state/0]).
 
--define(ADD_COUNTER_FIELDS, [committed_offset, forced_gcs, packets, readers]).
 -define(C_COMMITTED_OFFSET, ?C_NUM_LOG_FIELDS + 1).
 -define(C_FORCED_GCS, ?C_NUM_LOG_FIELDS + 2).
 -define(C_PACKETS, ?C_NUM_LOG_FIELDS + 3).
 -define(C_READERS, ?C_NUM_LOG_FIELDS + 4).
+-define(ADD_COUNTER_FIELDS,
+        [{committed_offset, ?C_COMMITTED_OFFSET, counter, "Last committed offset"},
+         {forced_gcs, ?C_FORCED_GCS, counter, "Number of garbage collection runs"},
+         {packets, ?C_PACKETS, counter, "Number of packets"},
+         {readers, ?C_READERS, counter, "Number of readers"}]).
+
 -define(DEFAULT_ONE_TIME_TOKEN_TIMEOUT, 30000).
 -define(TOKEN_SIZE, 32).
 -define(DEF_REC_BUF, 408300 * 5).

src/osiris_replica_reader.erl

@@ -39,8 +39,12 @@
          committed_offset = -1 :: -1 | osiris:offset(),
          offset_listener :: undefined | osiris:offset()}).
 
--define(COUNTER_FIELDS, [offset_listeners]).
 -define(C_OFFSET_LISTENERS, ?C_NUM_LOG_FIELDS + 1).
+-define(COUNTER_FIELDS,
+        [
+         {offset_listeners, ?C_OFFSET_LISTENERS, counter, "Number of offset listeners"}
+        ]
+       ).
 
 -spec maybe_connect(list(), integer(), list()) ->
                        {ok, term(), term()} | {error, term()}.

src/osiris_writer.erl

@@ -32,9 +32,14 @@
          stop/1,
          delete/1]).
 
--define(ADD_COUNTER_FIELDS, [committed_offset, readers]).
 -define(C_COMMITTED_OFFSET, ?C_NUM_LOG_FIELDS + 1).
 -define(C_READERS, ?C_NUM_LOG_FIELDS + 2).
+-define(ADD_COUNTER_FIELDS,
+        [
+         {committed_offset, ?C_COMMITTED_OFFSET, counter, "Last committed offset"},
+         {readers, ?C_READERS, counter, "Number of readers"}
+        ]
+       ).
 
 %% primary osiris process
 %% batch writes incoming data