stats: extend base server metrics

src/knot/common/stats.c

@@ -17,6 +17,8 @@
 #include "knot/nameserver/query_module.h"
 #include "libknot/xdp.h"
 
+#define ARRAY_SIZE(array)       (sizeof(array) / sizeof((array)[0]))
+
 static uint64_t stats_get_counter(knot_atomic_uint64_t **stats_vals, uint32_t offset,
                                   unsigned threads)
 {
@@ -109,6 +111,26 @@ int stats_xdp(stats_dump_ctr_f fcn, stats_dump_ctx_t *ctx)
 	return KNOT_EOK;
 }
 
+const char *server_stat_names[] = {
+	"udp_received",
+	"udp_async_done",
+	"udp_no_req_obj",
+	"udp_req_batch_limited",
+	"tcp_accept",
+	"tcp_received",
+	"tcp_async_done",
+	"tcp_no_req_obj",
+	"tcp_multiple_req",
+};
+
+static knot_atomic_uint64_t server_stat_counters[ARRAY_SIZE(server_stat_names)];
+
+void server_stats_increment_counter(server_stats_counter_t counter, uint64_t value)
+{
+	assert(counter < server_stats_max);
+	ATOMIC_ADD(server_stat_counters[counter], value);
+}
+
 #define DUMP_VAL(params, it, val) { \
 	(params).item = (it); \
 	(params).value = (val); \
@@ -130,6 +152,9 @@ int stats_server(stats_dump_ctr_f fcn, stats_dump_ctx_t *ctx)
 	DUMP_VAL(params, "zone-update-error", ATOMIC_GET(ctx->server->stats.zone_update_error));
 	DUMP_VAL(params, "tcp-io-timeout", ATOMIC_GET(ctx->server->stats.tcp_io_timeout));
 	DUMP_VAL(params, "tcp-idle-timeout", ATOMIC_GET(ctx->server->stats.tcp_idle_timeout));
+	for (size_t i = 0; i < ARRAY_SIZE(server_stat_names); i++) {
+		DUMP_VAL(params, server_stat_names[i], ATOMIC_GET(server_stat_counters[i]));
+	}
 
 	return KNOT_EOK;
 }
@@ -450,6 +475,8 @@ static void *dumper(void *data)
 
 void stats_reconfigure(conf_t *conf, server_t *server)
 {
+	_Static_assert(server_stats_max == ARRAY_SIZE(server_stat_names), ""); // Ensure enum and names are setup consistently.
+
 	if (conf == NULL || server == NULL) {
 		return;
 	}

src/knot/common/stats.h

@@ -49,6 +49,27 @@ typedef struct {
  */
 typedef int (*stats_dump_ctr_f)(stats_dump_params_t *, stats_dump_ctx_t *);
 
+/*!
+ * \brief Statistics metrics item.
+ */
+typedef enum {
+	server_stats_udp_received,
+	server_stats_udp_async_done,
+	server_stats_udp_no_req_obj,
+	server_stats_udp_req_batch_limited,
+	server_stats_tcp_accept,
+	server_stats_tcp_received,
+	server_stats_tcp_async_done,
+	server_stats_tcp_no_req_obj,
+	server_stats_tcp_multiple_req,
+	server_stats_max,
+} server_stats_counter_t;
+
+/*!
+ * \brief Increment the server stats.
+ */
+void server_stats_increment_counter(server_stats_counter_t counter, uint64_t value);
+
 /*!
  * \brief XDP metrics.
  */

src/knot/server/tcp-handler.c

@@ -33,6 +33,7 @@
 #include "contrib/sockaddr.h"
 #include "contrib/time.h"
 #include "contrib/ucw/mempool.h"
+#include "knot/common/stats.h"
 
 /*! \brief TCP context data. */
 typedef struct tcp_context {
@@ -338,12 +339,16 @@ static void tcp_wait_for_events(tcp_context_t *tcp)
 			if (idx < tcp->client_threshold) {
 				/* Don't accept more clients than configured. */
 				if (fdset_get_length(set) < tcp->max_worker_fds) {
+					server_stats_increment_counter(server_stats_tcp_accept, 1);
 					tcp_event_accept(tcp, idx, iface);
 				}
-			/* Client sockets - already accepted connection or
-			   closed connection :-( */
-			} else if (tcp_event_serve(tcp, idx, iface) != KNOT_EOK) {
-				should_close = true;
+			} else {
+				server_stats_increment_counter(server_stats_tcp_received, 1);
+				/* Client sockets - already accepted connection or
+				   closed connection :-( */
+				if (tcp_event_serve(tcp, idx, iface) != KNOT_EOK) {
+					should_close = true;
+				}
 			}
 		}
 

src/knot/server/udp-handler.c

@@ -27,6 +27,7 @@
 #include "contrib/ucw/mempool.h"
 #include "knot/common/fdset.h"
 #include "knot/common/log.h"
+#include "knot/common/stats.h"
 #include "knot/nameserver/process_query.h"
 #include "knot/query/layer.h"
 #include "knot/server/handler.h"
@@ -618,6 +619,7 @@ int udp_master(dthread_t *thread)
 			if (!fdset_it_is_pollin(&it)) {
 				continue;
 			}
+			server_stats_increment_counter(server_stats_udp_received, 1);
 			if (api->udp_recv(fdset_it_get_fd(&it), api_ctx) > 0) {
 				const iface_t *iface = fdset_it_get_ctx(&it);
 				assert(iface);