Merge branch 'Ayanda-D-configurable-mgmt-delegate-pool'

(cherry picked from commit 569edb0)

Author: michaelklishin

deps/rabbitmq_management/BUILD.bazel

@@ -35,7 +35,8 @@ APP_ENV = """[
 	    {cors_allow_origins, []},
 	    {cors_max_age, 1800},
 	    {content_security_policy, "script-src 'self' 'unsafe-eval' 'unsafe-inline'; object-src 'self'"},
-	    {max_http_body_size, 10000000}
+	    {max_http_body_size, 10000000},
+        {delegate_count, 5}
 	  ]"""
 
 genrule(

deps/rabbitmq_management/Makefile

@@ -13,7 +13,8 @@ define PROJECT_ENV
 	    {cors_allow_origins, []},
 	    {cors_max_age, 1800},
 	    {content_security_policy, "script-src 'self' 'unsafe-eval' 'unsafe-inline'; object-src 'self'"},
-	    {max_http_body_size, 10000000}
+	    {max_http_body_size, 10000000},
+	    {delegate_count, 5}
 	  ]
 endef
 

deps/rabbitmq_management/priv/schema/rabbitmq_management.schema

@@ -37,6 +37,15 @@ fun(Conf) ->
 end}.
 
 
+%% Number of delegate processes to use for metrics acquisition intra-cluster
+%% communication. On a machine which has a very large number of cores and is
+%% also part of a cluster, you may wish to increase this value.
+%%
+
+{mapping, "management.delegate_count", "rabbitmq_management.delegate_count", [
+    {datatype, integer}, {validators, ["non_negative_integer"]}
+]}.
+
 %% HTTP (TCP) listener options ========================================================
 
 %% HTTP listener consistent with Web STOMP and Web MQTT.

deps/rabbitmq_management_agent/src/rabbit_mgmt_agent_sup.erl

@@ -37,9 +37,10 @@ maybe_enable_metrics_collector() ->
     case rabbit_mgmt_agent_config:is_metrics_collector_enabled() of
         true ->
             ok = pg:join(?MANAGEMENT_PG_SCOPE, ?MANAGEMENT_PG_GROUP, self()),
+            MDC = get_management_delegate_count(),
             ST = {rabbit_mgmt_storage, {rabbit_mgmt_storage, start_link, []},
                   permanent, ?WORKER_WAIT, worker, [rabbit_mgmt_storage]},
-            MD = {delegate_management_sup, {delegate_sup, start_link, [5, ?DELEGATE_PREFIX]},
+            MD = {delegate_management_sup, {delegate_sup, start_link, [MDC, ?DELEGATE_PREFIX]},
                   permanent, ?SUPERVISOR_WAIT, supervisor, [delegate_sup]},
             MC = [{rabbit_mgmt_metrics_collector:name(Table),
                    {rabbit_mgmt_metrics_collector, start_link, [Table]},
@@ -55,3 +56,6 @@ maybe_enable_metrics_collector() ->
         false ->
             []
     end.
+
+get_management_delegate_count() ->
+    application:get_env(rabbitmq_management, delegate_count, 5).