net: change metrics registration logic

Author: WillemKauf

src/v/net/server.cc

@@ -49,13 +49,11 @@ server::~server() = default;
 
 void server::start() {
     if (!cfg.disable_metrics) {
-        setup_metrics();
-        _probe->setup_metrics(_metrics, cfg.name.c_str());
+        setup_internal_metrics();
     }
 
     if (!cfg.disable_public_metrics) {
         setup_public_metrics();
-        _probe->setup_public_metrics(_public_metrics, cfg.name.c_str());
     }
 
     if (cfg.connection_rate_bindings) {
@@ -320,6 +318,10 @@ ss::future<> server::stop() {
     if (_as.abort_requested()) {
         return ss::now();
     }
+
+    _metrics.clear();
+    _public_metrics.clear();
+
     // if shutdown_input wasn't called fallback to previous behavior i.e. stop()
     // waits for shutdown
     return wait_for_shutdown();
@@ -329,7 +331,10 @@ void server::set_memory_capacity(uint64_t new_capacity) {
     _memory.set_capacity(new_capacity);
 }
 
-void server::setup_metrics() {
+void server::setup_internal_metrics() {
+    if (_metrics_setup) {
+        return;
+    }
     namespace sm = ss::metrics;
     _metrics.add_group(
       prometheus_sanitize::metrics_name(cfg.name),
@@ -348,9 +353,14 @@ void server::setup_metrics() {
          "dispatch_handler_latency",
          [this] { return _hist.internal_histogram_logform(); },
          sm::description(ssx::sformat("{}: Latency ", cfg.name)))});
+    _probe->setup_metrics(_metrics, cfg.name.c_str());
+    _metrics_setup = true;
 }
 
 void server::setup_public_metrics() {
+    if (_public_metrics_setup) {
+        return;
+    }
     namespace sm = ss::metrics;
 
     std::string_view server_name(cfg.name);
@@ -369,6 +379,8 @@ void server::setup_public_metrics() {
          {server_label(server_name)},
          [this] { return _hist.public_histogram_logform(); })
          .aggregate({sm::shard_label})});
+    _probe->setup_public_metrics(_public_metrics, cfg.name.c_str());
+    _public_metrics_setup = true;
 }
 
 fmt::iterator server_configuration::format_to(fmt::iterator it) const {

src/v/net/server.h

@@ -149,6 +149,10 @@ class server {
     bool abort_requested() const { return _as.abort_requested(); }
     void set_memory_capacity(uint64_t new_capacity);
 
+protected:
+    void setup_internal_metrics();
+    void setup_public_metrics();
+
 private:
     struct listener {
         ss::sstring name;
@@ -180,6 +184,8 @@ class server {
     std::unique_ptr<server_probe> _probe;
     metrics::internal_metric_groups _metrics;
     metrics::public_metric_groups _public_metrics;
+    bool _metrics_setup{false};
+    bool _public_metrics_setup{false};
 
     std::optional<config_connection_rate_bindings> connection_rate_bindings;
     std::optional<connection_rate<>> _connection_rates;

src/v/rpc/rpc_server.h

@@ -35,19 +35,21 @@ class rpc_server : public net::server {
     rpc_server(const rpc_server&) = delete;
     rpc_server& operator=(const rpc_server&) = delete;
 
-    void set_all_services_added() { _all_services_added = true; }
+    void set_all_services_added() {
+        _all_services_added = true;
+        if (!config::shard_local_cfg().disable_metrics()) {
+            for (auto& s : _services) {
+                s->setup_metrics();
+            }
+        }
+    }
 
     // Adds the given services to the protocol.
     // May be called whether or not the server has already been started.
     void add_services(std::vector<std::unique_ptr<service>> services) {
         vassert(
           !_all_services_added,
           "Adding service after all services already added");
-        if (!config::shard_local_cfg().disable_metrics()) {
-            for (auto& s : services) {
-                s->setup_metrics();
-            }
-        }
         std::move(
           services.begin(), services.end(), std::back_inserter(_services));
     }
@@ -63,6 +65,15 @@ class rpc_server : public net::server {
         _services.push_back(std::make_unique<T>(std::forward<Args>(args)...));
     }
 
+    void setup_metrics() {
+        if (!config::shard_local_cfg().disable_metrics()) {
+            net::server::setup_internal_metrics();
+        }
+        if (!config::shard_local_cfg().disable_public_metrics()) {
+            net::server::setup_public_metrics();
+        }
+    }
+
 private:
     ss::future<>
       dispatch_method_once(header, ss::lw_shared_ptr<net::connection>);