Configure ra metrics handler

[#157193081]

Author: dcorbacho

mk/rabbitmq-run.mk

@@ -167,7 +167,8 @@ define test_rabbitmq_config
       {loopback_users, []}
     ]},
   {ra, [
-      {data_dir, "$(RABBITMQ_QUORUM_DIR)"}
+      {data_dir, "$(RABBITMQ_QUORUM_DIR)"},
+      {metrics_handler, {rabbit_quorum_queue, io_metrics_handler}}
     ]}
 ].
 endef
@@ -201,7 +202,8 @@ define test_rabbitmq_config_with_tls
         ]}
   ]},
   {ra, [
-      {data_dir, "$(RABBITMQ_QUORUM_DIR)"}
+      {data_dir, "$(RABBITMQ_QUORUM_DIR)"},
+      {metrics_handler, {rabbit_quorum_queue, io_metrics_handler}}
     ]}
 ].
 endef
@@ -320,6 +322,7 @@ start-brokers start-cluster:
 		  RABBITMQ_SERVER_START_ARGS=" \
 		  -rabbit loopback_users [] \
 		  -ra data_dir "$(RABBITMQ_QUORUM_DIR)"
+	          -ra metrics_handler {rabbit_quorum_queue, io_metrics_handler}
 		  -rabbitmq_management listener [{port,$$((15672 + $$n - 1))}] \
 		  "; \
 		if test '$@' = 'start-cluster' && test "$$nodename1"; then \

src/file_handle_cache_stats.erl

@@ -19,6 +19,7 @@
 %% stats about read / write operations that go through the fhc.
 
 -export([init/0, update/3, update/2, update/1, get/0]).
+-export([safe_update/2]).
 
 -define(TABLE, ?MODULE).
 
@@ -51,6 +52,19 @@ update(Op, Thunk) ->
     _ = ets:update_counter(?TABLE, {Op, time}, Time),
     Res.
 
+safe_update(Op, Thunk) ->
+    {Time, Res} = timer_tc(Thunk),
+    try
+        _ = ets:update_counter(?TABLE, {Op, count}, 1),
+        _ = ets:update_counter(?TABLE, {Op, time}, Time)
+    catch
+        error:badarg ->
+            %% This can happen on startup, when ra tries to open a file before
+            %% the core is initialised.
+            ok
+    end,
+    Res.
+
 update(Op) ->
     ets:update_counter(?TABLE, {Op, count}, 1),
     ok.