From: Diego Fronza <diego@isc.org>
Date: Tue, 5 Nov 2019 20:48:47 +0000 (-0300)
Subject: Added TCP high-water statistics variable
X-Git-Tag: v9.14.8~9^2~4
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=d5cc3ed3813723ee745b3329abace0b4202fe171;p=thirdparty%2Fbind9.git

Added TCP high-water statistics variable

This variable will report the maximum number of simultaneous tcp clients
that BIND has served while running.

It can be verified by running rndc status, then inspect "tcp high-water:
count", or by generating statistics file, rndc stats, then inspect the
line with "TCP connection high-water" text.

The tcp-highwater variable is atomically updated based on an existing
tcp-quota system handled in ns/client.c.

(cherry picked from commit 66fe8627de2c8488b7808c7b342e6ceb51f65414)
---

diff --git a/bin/named/server.c b/bin/named/server.c
index 86d4eb82508..6e54dcaeb42 100644
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -11583,6 +11583,11 @@ named_server_status(named_server_t *server, isc_buffer_t **text) {
 		     isc_quota_getmax(&server->sctx->tcpquota));
 	CHECK(putstr(text, line));
 
+	snprintf(line, sizeof(line), "TCP high-water: %u\n",
+		     (unsigned)ns_stats_get_counter(server->sctx->nsstats,
+					  ns_statscounter_tcphighwater));
+	CHECK(putstr(text, line));
+
 	if (server->reload_in_progress) {
 		CHECK(putstr(text, "reload/reconfig in progress"));
 	}
diff --git a/bin/named/statschannel.c b/bin/named/statschannel.c
index b32d72f6d9e..abaeed5e8ed 100644
--- a/bin/named/statschannel.c
+++ b/bin/named/statschannel.c
@@ -234,6 +234,8 @@ init_desc(void) {
 	SET_NSSTATDESC(invalidsig, "requests with invalid signature",
 		       "ReqBadSIG");
 	SET_NSSTATDESC(requesttcp, "TCP requests received", "ReqTCP");
+	SET_NSSTATDESC(tcphighwater, "TCP connection high-water",
+		       "TCPConnHighWater");
 	SET_NSSTATDESC(authrej, "auth queries rejected", "AuthQryRej");
 	SET_NSSTATDESC(recurserej, "recursive queries rejected", "RecQryRej");
 	SET_NSSTATDESC(xfrrej, "transfer requests rejected", "XfrRej");
@@ -315,6 +317,7 @@ init_desc(void) {
 		       "QryUsedStale");
 	SET_NSSTATDESC(prefetch, "queries triggered prefetch", "Prefetch");
 	SET_NSSTATDESC(keytagopt, "Keytag option received", "KeyTagOpt");
+
 	INSIST(i == ns_statscounter_max);
 
 	/* Initialize resolver statistics */
diff --git a/lib/ns/client.c b/lib/ns/client.c
index e84a3c853cd..22a0cb66289 100644
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -3465,7 +3465,6 @@ client_accept(ns_client_t *client) {
 	isc_result_t result;
 
 	CTRACE("accept");
-
 	/*
 	 * Set up a new TCP connection. This means try to attach to the
 	 * TCP client quota (tcp-clients), but fail if we're over quota.
@@ -3516,6 +3515,12 @@ client_accept(ns_client_t *client) {
 		RUNTIME_CHECK(result == ISC_R_SUCCESS);
 	}
 
+	/* TCP high-water stats update. */
+	unsigned int curr_tcpquota = isc_quota_getused(&client->sctx->tcpquota);
+	ns_stats_update_if_greater(client->sctx->nsstats,
+				   ns_statscounter_tcphighwater,
+				   curr_tcpquota);
+
 	/*
 	 * If this client was set up using get_client() or get_worker(),
 	 * then TCP is already marked active. However, if it was restarted
diff --git a/lib/ns/include/ns/stats.h b/lib/ns/include/ns/stats.h
index f456a971b0a..175813113eb 100644
--- a/lib/ns/include/ns/stats.h
+++ b/lib/ns/include/ns/stats.h
@@ -102,7 +102,9 @@ enum {
 	ns_statscounter_prefetch = 63,
 	ns_statscounter_keytagopt = 64,
 
-	ns_statscounter_max = 65
+	ns_statscounter_tcphighwater = 65,
+
+	ns_statscounter_max = 66,
 };
 
 void