More Prometheus metrics

src/resolver.rs

@@ -115,7 +115,12 @@ pub async fn resolve(
         trace!("SERVFAIL/REFUSED: {}", dns::rcode(&response));
         if let Some(cached_response) = cached_response {
             trace!("Serving stale");
+            #[cfg(feature = "metrics")]
+            globals.varz.client_queries_offline.inc();
             return Ok(cached_response.into_response());
+        } else {
+            #[cfg(feature = "metrics")]
+            globals.varz.client_queries_errors.inc();
         }
     } else {
         trace!("Adding to cache");
@@ -133,6 +138,8 @@ pub async fn get_cached_response_or_resolve(
     let packet_qname = dns::qname(&packet)?;
     if let Some(blacklist) = &globals.blacklist {
         if blacklist.find(&packet_qname) {
+            #[cfg(feature = "metrics")]
+            globals.varz.client_queries_blocked.inc();
             return dns::serve_empty_response(packet.to_vec());
         }
     }
@@ -156,9 +163,13 @@ pub async fn get_cached_response_or_resolve(
             cached_response.set_tid(original_tid);
             if !cached_response.has_expired() {
                 trace!("Cached");
+                #[cfg(feature = "metrics")]
+                globals.varz.client_queries_cached.inc();
                 return Ok(cached_response.into_response());
             }
             trace!("Expired");
+            #[cfg(feature = "metrics")]
+            globals.varz.client_queries_expired.inc();
             Some(cached_response)
         }
     };

src/varz.rs

@@ -7,11 +7,6 @@ pub struct StartInstant(pub Instant);
 pub struct Inner {
     pub start_instant: StartInstant,
     pub uptime: Gauge,
-    pub cache_frequent_len: Gauge,
-    pub cache_recent_len: Gauge,
-    pub cache_test_len: Gauge,
-    pub cache_inserted: Gauge,
-    pub cache_evicted: Gauge,
     pub client_queries: Gauge,
     pub client_queries_udp: Counter,
     pub client_queries_tcp: Counter,
@@ -19,6 +14,7 @@ pub struct Inner {
     pub client_queries_expired: Counter,
     pub client_queries_offline: Counter,
     pub client_queries_errors: Counter,
+    pub client_queries_blocked: Counter,
     pub inflight_udp_queries: Gauge,
     pub inflight_tcp_queries: Gauge,
     pub upstream_errors: Counter,
@@ -44,39 +40,6 @@ impl Inner {
                 labels! {"handler" => "all",}
             ))
             .unwrap(),
-            cache_frequent_len: register_gauge!(opts!(
-                "encrypted_dns_cache_frequent_len",
-                "Number of entries in the cached set of \
-                 frequent items",
-                labels! {"handler" => "all",}
-            ))
-            .unwrap(),
-            cache_recent_len: register_gauge!(opts!(
-                "encrypted_dns_cache_recent_len",
-                "Number of entries in the cached set of \
-                 recent items",
-                labels! {"handler" => "all",}
-            ))
-            .unwrap(),
-            cache_test_len: register_gauge!(opts!(
-                "encrypted_dns_cache_test_len",
-                "Number of entries in the cached set of \
-                 staged items",
-                labels! {"handler" => "all",}
-            ))
-            .unwrap(),
-            cache_inserted: register_gauge!(opts!(
-                "encrypted_dns_cache_inserted",
-                "Number of entries added to the cache",
-                labels! {"handler" => "all",}
-            ))
-            .unwrap(),
-            cache_evicted: register_gauge!(opts!(
-                "encrypted_dns_cache_evicted",
-                "Number of entries evicted from the cache",
-                labels! {"handler" => "all",}
-            ))
-            .unwrap(),
             client_queries: register_gauge!(opts!(
                 "encrypted_dns_client_queries",
                 "Number of client queries received",
@@ -124,6 +87,12 @@ impl Inner {
                 labels! {"handler" => "all",}
             ))
             .unwrap(),
+            client_queries_blocked: register_counter!(opts!(
+                "encrypted_dns_client_queries_blocked",
+                "Number of blocked client queries",
+                labels! {"handler" => "all",}
+            ))
+            .unwrap(),
             inflight_udp_queries: register_gauge!(opts!(
                 "encrypted_dns_inflight_udp_queries",
                 "Number of UDP queries currently waiting for a response",