From: Remi Gacogne <remi.gacogne@powerdns.com>
Date: Mon, 6 Apr 2020 13:05:37 +0000 (+0200)
Subject: auth: Add a new 'backend-queries' metric
X-Git-Tag: auth-4.4.0-alpha2~8^2~3
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=d04143d5311b334d5c1362dbc86dc41b08980b04;p=thirdparty%2Fpdns.git

auth: Add a new 'backend-queries' metric

Counting the numbers of queries sent to the backend(s), instead of
relying on the number of cache misses.
---

diff --git a/pdns/dnsbackend.cc b/pdns/dnsbackend.cc
index 12ba56b2fc..8ead24b379 100644
--- a/pdns/dnsbackend.cc
+++ b/pdns/dnsbackend.cc
@@ -32,6 +32,9 @@
 #include "pdns/packetcache.hh"
 #include "dnspacket.hh"
 #include "dns.hh"
+#include "statbag.hh"
+
+extern StatBag S;
 
 // this has to be somewhere central, and not in a file that requires Lua
 // this is so the geoipbackend can set this pointer if loaded for lua-record.cc
@@ -241,6 +244,7 @@ vector<DNSBackend *> BackendMakerClass::all(bool metadataOnly)
 bool DNSBackend::getSOA(const DNSName &domain, SOAData &sd)
 {
   this->lookup(QType(QType::SOA),domain,-1);
+  S.inc("backend-queries");
 
   DNSResourceRecord rr;
   rr.auth = true;
diff --git a/pdns/ueberbackend.cc b/pdns/ueberbackend.cc
index 0a897649db..18a6e4b0be 100644
--- a/pdns/ueberbackend.cc
+++ b/pdns/ueberbackend.cc
@@ -57,6 +57,7 @@ bool UeberBackend::d_go=false;
 bool UeberBackend::s_doANYLookupsOnly=false;
 std::mutex UeberBackend::d_mut;
 std::condition_variable UeberBackend::d_cond;
+AtomicCounter* UeberBackend::s_backendQueries = nullptr;
 
 //! Loads a module and reports it to all UeberBackend threads
 bool UeberBackend::loadmodule(const string &name)
@@ -99,6 +100,9 @@ void UeberBackend::go(void)
     s_doANYLookupsOnly = true;
   }
 
+  S.declare("backend-queries", "Number of queries sent to the backend(s)");
+  s_backendQueries = S.getPointer("backend-queries");
+
   {
     std::unique_lock<std::mutex> l(d_mut);
     d_go = true;
@@ -612,6 +616,7 @@ void UeberBackend::lookup(const QType &qtype,const DNSName &qname, int zoneId, D
       d_negcached=d_cached=false;
       d_answers.clear(); 
       (d_handle.d_hinterBackend=backends[d_handle.i++])->lookup(d_handle.qtype, d_handle.qname, d_handle.zoneId, d_handle.pkt_p);
+      ++(*s_backendQueries);
     } 
     else if(cstat==0) {
       //      cout<<"UeberBackend::lookup("<<qname<<"|"<<DNSRecordContent::NumberToType(qtype.getCode())<<"): NEGcached"<<endl;
@@ -719,6 +724,7 @@ bool UeberBackend::handle::get(DNSZoneRecord &r)
       
       d_hinterBackend=parent->backends[i++];
       d_hinterBackend->lookup(qtype,qname,zoneId,pkt_p);
+      ++(*s_backendQueries);
     }
     else 
       break;
diff --git a/pdns/ueberbackend.hh b/pdns/ueberbackend.hh
index d708569add..09149cdaca 100644
--- a/pdns/ueberbackend.hh
+++ b/pdns/ueberbackend.hh
@@ -153,6 +153,7 @@ private:
 
   bool d_negcached;
   bool d_cached;
+  static AtomicCounter* s_backendQueries;
   static bool d_go;
   bool d_stale;
   static bool s_doANYLookupsOnly;
diff --git a/regression-tests.nobackend/counters/command b/regression-tests.nobackend/counters/command
index 9ff54727d7..91ef56e8dc 100755
--- a/regression-tests.nobackend/counters/command
+++ b/regression-tests.nobackend/counters/command
@@ -27,7 +27,7 @@ $SDIG ::1 $port example.com SOA >&2 >/dev/null
 $SDIG ::1 $port example.com SOA tcp >&2 >/dev/null
 
 $PDNSCONTROL --config-name= --no-config --socket-dir=./ 'show *' | \
-  tr ',' '\n'| grep -v -E '(user-msec|sys-msec|cpu-iowait|cpu-steal|uptime|udp-noport-errors|udp-in-errors|real-memory-usage|special-memory-usage|udp-recvbuf-errors|udp-sndbuf-errors|-hit|-miss|fd-usage|latency)' | LC_ALL=C sort
+  tr ',' '\n'| grep -v -E '(user-msec|sys-msec|cpu-iowait|cpu-steal|uptime|udp-noport-errors|udp-in-errors|real-memory-usage|special-memory-usage|udp-recvbuf-errors|udp-sndbuf-errors|-hit|-miss|fd-usage|latency|backend-queries)' | LC_ALL=C sort
 
 kill $(cat pdns*.pid)
 rm pdns*.pid