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.

diff --git a/bin/named/server.c b/bin/named/server.c
index 0cbd462b1de49e3b089fb5a6e2f667ada3dd10a0..e7f87e349e9e72d9180f7abb6a1a500ac86c226f 100644 (file)
--- a/bin/named/server.c
+++ b/bin/named/server.c
@@ -11447,6 +11447,11 @@ 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_status != NAMED_RELOAD_DONE) {
                snprintf(line, sizeof(line), "reload/reconfig %s\n",
                         server->reload_status == NAMED_RELOAD_FAILED

diff --git a/bin/named/statschannel.c b/bin/named/statschannel.c
index d7f864acec26edae58db0e3f7979b0382a7c40d0..a955d7b207fb2ae8d6e4eb7fc6af72d25c2a5008 100644 (file)
--- a/bin/named/statschannel.c
+++ b/bin/named/statschannel.c
@@ -241,6 +241,8 @@ 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");
@@ -322,6 +324,7 @@ 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/isc/stats.c b/lib/isc/stats.c
index 1df53498a95d1d499701b29e593052d7f4212d2e..44cc2d4e1bc648af03979ffecfcb0adcd8a1aaf0 100644 (file)
--- a/lib/isc/stats.c
+++ b/lib/isc/stats.c
@@ -29,17 +29,17 @@
 #define ISC_STATS_VALID(x)             ISC_MAGIC_VALID(x, ISC_STATS_MAGIC)
 
 #if defined(_WIN32) && !defined(_WIN64)
-typedef atomic_int_fast32_t isc_stat_t;
+       typedef atomic_int_fast32_t isc__atomic_statcounter_t;
 #else
-typedef atomic_int_fast64_t isc_stat_t;
+       typedef atomic_int_fast64_t isc__atomic_statcounter_t;
 #endif
 
 struct isc_stats {
-       unsigned int            magic;
-       isc_mem_t               *mctx;
-       isc_refcount_t          references;
-       int                     ncounters;
-       isc_stat_t              *counters;
+       unsigned int                    magic;
+       isc_mem_t                       *mctx;
+       isc_refcount_t                  references;
+       int                             ncounters;
+       isc__atomic_statcounter_t       *counters;
 };
 
 static isc_result_t

diff --git a/lib/ns/client.c b/lib/ns/client.c
index f16ece8c49f1ffa54523256d74f2f7c8a2d8e816..598e41179ec38ed4b3b7a48679aa867f982ff0e7 100644 (file)
--- a/lib/ns/client.c
+++ b/lib/ns/client.c
@@ -3400,7 +3400,6 @@ 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.
@@ -3451,6 +3450,12 @@ 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 f456a971b0a2b112b329dc45071e98aea31c544a..175813113ebffa3ff6f5f797499c533e044869cf 100644 (file)
--- 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