From: Evan Hunt <each@isc.org>
Date: Tue, 26 Nov 2019 05:28:10 +0000 (-0800)
Subject: add a stats counter for clients dropped due to recursive-clients limit
X-Git-Tag: v9.11.14~23^2
X-Git-Url: http://git.ipfire.org/gitweb/?a=commitdiff_plain;h=47da3129fd6af8cde69703c696514ec1e25b93bb;p=thirdparty%2Fbind9.git

add a stats counter for clients dropped due to recursive-clients limit

(cherry picked from commit 715afa9c5771ca5b483aad77fe21906685d63889)
---

diff --git a/CHANGES b/CHANGES
index c9751295a39..500ff6c1be8 100644
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,7 @@
+5327.	[func]		Added a statistics counter to track queries
+			dropped because the recursive-clients quota was
+			exceeded. [GL #1399]
+
 5326.	[bug]		Add python dependancy on 'distutils.core' to configure.
 			'distutils.core' is required for installation.
 			[GL #1397]
diff --git a/bin/named/client.c b/bin/named/client.c
index 50fa2cd6c4d..f8431bc36ad 100644
--- a/bin/named/client.c
+++ b/bin/named/client.c
@@ -286,8 +286,11 @@ ns_client_killoldestquery(ns_client_t *client) {
 		ISC_LIST_UNLINK(client->manager->recursing, oldest, rlink);
 		UNLOCK(&client->manager->reclock);
 		ns_query_cancel(oldest);
-	} else
+		isc_stats_increment(ns_g_server->nsstats,
+				    dns_nsstatscounter_reclimitdropped);
+	} else {
 		UNLOCK(&client->manager->reclock);
+	}
 }
 
 void
diff --git a/bin/named/include/named/server.h b/bin/named/include/named/server.h
index 7ee8f66d28a..3f96b7b78f8 100644
--- a/bin/named/include/named/server.h
+++ b/bin/named/include/named/server.h
@@ -222,7 +222,9 @@ enum {
 
 	dns_nsstatscounter_tcphighwater = 57,
 
-	dns_nsstatscounter_max = 58
+	dns_nsstatscounter_reclimitdropped = 58,
+
+	dns_nsstatscounter_max = 59
 };
 
 /*%
diff --git a/bin/named/statschannel.c b/bin/named/statschannel.c
index 4cdf7d6fb66..a243599ab17 100644
--- a/bin/named/statschannel.c
+++ b/bin/named/statschannel.c
@@ -297,6 +297,9 @@ init_desc(void) {
 		"QryNXRedirRLookup");
 	SET_NSSTATDESC(badcookie, "sent badcookie response", "QryBADCOOKIE");
 	SET_NSSTATDESC(keytagopt, "Keytag option received", "KeyTagOpt");
+	SET_NSSTATDESC(reclimitdropped,
+		       "queries dropped due to recursive client limit",
+		       "RecLimitDropped");
 	INSIST(i == dns_nsstatscounter_max);
 
 	/* Initialize resolver statistics */
diff --git a/bin/tests/system/fetchlimit/tests.sh b/bin/tests/system/fetchlimit/tests.sh
index b77ba7bb9e2..b27d464fbe3 100644
--- a/bin/tests/system/fetchlimit/tests.sh
+++ b/bin/tests/system/fetchlimit/tests.sh
@@ -179,5 +179,17 @@ echo_i "clients count exceeded 360 on $exceeded trials (expected 0)"
 if [ $ret != 0 ]; then echo_i "failed"; fi
 status=`expr $status + $ret`
 
+echo_i "checking drop statistics"
+rm -f ns3/named.stats
+$RNDCCMD stats
+for try in 1 2 3 4 5; do
+    [ -f ns3/named.stats ] && break
+    sleep 1
+done
+drops=`grep 'queries dropped due to recursive client limit' ns3/named.stats | sed 's/\([0-9][0-9]*\) queries.*/\1/'`
+[ "${drops:-0}" -ne 0 ] || ret=1
+if [ $ret != 0 ]; then echo_i "failed"; fi
+status=`expr $status + $ret`
+
 echo_i "exit status: $status"
 [ $status -eq 0 ] || exit 1