Add extra metrics to session_mgr

- Sessions killed by activity
- Current number of sessions across all types

src/Stats.cc

@@ -119,7 +119,7 @@ void ProfileLogger::Log() {
 
     // TODO: This previously output the number of connections, but now that we're storing
     // sessions as well as connections, this might need to be renamed.
-    file->Write(util::fmt("%.06f Conns: total=%" PRIu64 " current=%" PRIu64 "/%u\n", run_state::network_time,
+    file->Write(util::fmt("%.06f Conns: total=%" PRIu64 " current=%" PRIu64 "/%zu\n", run_state::network_time,
                           Connection::TotalConnections(), Connection::CurrentConnections(),
                           session_mgr->CurrentSessions()));
 

src/session/Manager.cc

@@ -46,9 +46,9 @@ public:
 
     ProtocolMap::iterator InitCounters(const std::string& protocol) {
         auto active_family =
-            telemetry_mgr->GaugeFamily("zeek", "active-sessions", {"protocol"}, "Active Zeek Sessions");
+            telemetry_mgr->GaugeFamily("zeek", "active_sessions", {"protocol"}, "Active Zeek Sessions");
         auto total_family =
-            telemetry_mgr->CounterFamily("zeek", "total-sessions", {"protocol"}, "Total number of sessions");
+            telemetry_mgr->CounterFamily("zeek", "total_sessions", {"protocol"}, "Total number of sessions");
 
         auto [it, inserted] = entries.insert({protocol, Protocol{active_family, total_family, protocol}});
 
@@ -75,7 +75,17 @@ private:
 
 } // namespace detail
 
-Manager::Manager() { stats = new detail::ProtocolStats(); }
+Manager::Manager() {
+    stats = new detail::ProtocolStats();
+    ended_sessions_metric_family = telemetry_mgr->CounterFamily("zeek", "ended_sessions", {"reason"},
+                                                                "Number of sessions ended for specific reasons");
+    ended_by_inactivity_metric =
+        ended_sessions_metric_family->GetOrAdd({{"reason", "inactivity"}}, []() -> prometheus::ClientMetric {
+            prometheus::ClientMetric metric;
+            metric.counter.value = static_cast<double>(zeek::detail::killed_by_inactivity);
+            return metric;
+        });
+}
 
 Manager::~Manager() {
     Clear();

src/session/Manager.h

@@ -13,6 +13,13 @@
 
 namespace zeek {
 
+namespace telemetry {
+class CounterFamily;
+using CounterFamilyPtr = std::shared_ptr<CounterFamily>;
+class Counter;
+using CounterPtr = std::shared_ptr<Counter>;
+} // namespace telemetry
+
 namespace detail {
 class PacketFilter;
 }
@@ -82,7 +89,7 @@ public:
     void Weird(const char* name, const Packet* pkt, const char* addl = "", const char* source = "");
     void Weird(const char* name, const IP_Hdr* ip, const char* addl = "");
 
-    unsigned int CurrentSessions() { return session_map.size(); }
+    size_t CurrentSessions() { return session_map.size(); }
 
 private:
     using SessionMap = std::unordered_map<detail::Key, Session*, detail::KeyHash>;
@@ -96,6 +103,8 @@ private:
 
     SessionMap session_map;
     detail::ProtocolStats* stats;
+    telemetry::CounterFamilyPtr ended_sessions_metric_family;
+    telemetry::CounterPtr ended_by_inactivity_metric;
 };
 
 } // namespace session

src/stats.bif

@@ -83,7 +83,7 @@ function get_conn_stats%(%): ConnStats
 
 	r->Assign(n++, Connection::TotalConnections());
 	r->Assign(n++, Connection::CurrentConnections());
-	r->Assign(n++, session_mgr->CurrentSessions());
+	r->Assign(n++, static_cast<uint64_t>(session_mgr->CurrentSessions()));
 
 	session::Stats s;
 	if ( session_mgr )

testing/btest/Baseline/scripts.base.frameworks.telemetry.basic/out

@@ -1,5 +1,6 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
-### zeek_session_metrics |2|
+### zeek_session_metrics |3|
+Telemetry::COUNTER, zeek, zeek_ended_sessions_total, [reason], [inactivity], 0.0
 Telemetry::COUNTER, zeek, zeek_total_sessions_total, [protocol], [tcp], 500.0
 Telemetry::GAUGE, zeek, zeek_active_sessions, [protocol], [tcp], 500.0
 ### bt* metrics |5|

testing/btest/Baseline/scripts.policy.frameworks.telemetry.log/telemetry.log.filtered

@@ -1,5 +1,7 @@
 ### BTest baseline data generated by btest-diff. Do not edit. Use "btest -U/-u" to update. Requires BTest >= 0.63.
+XXXXXXXXXX.XXXXXX	zeek	counter	zeek_ended_sessions_total	reason	inactivity	0.0
 XXXXXXXXXX.XXXXXX	zeek	counter	zeek_total_sessions_total	protocol	tcp	1.0
 XXXXXXXXXX.XXXXXX	zeek	gauge	zeek_active_sessions	protocol	tcp	1.0
+XXXXXXXXXX.XXXXXX	zeek	counter	zeek_ended_sessions_total	reason	inactivity	0.0
 XXXXXXXXXX.XXXXXX	zeek	counter	zeek_total_sessions_total	protocol	tcp	500.0
 XXXXXXXXXX.XXXXXX	zeek	gauge	zeek_active_sessions	protocol	tcp	500.0