From: Michael Tremer <michael.tremer@ipfire.org>
Date: Sun, 12 Jul 2026 11:59:20 +0000 (+0000)
Subject: graphs: knot-resolver: Add a new latency graph
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=da419745e21b814727330ec5fe632049dcefefdd;p=telemetry.git

graphs: knot-resolver: Add a new latency graph

Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>
---

diff --git a/src/daemon/graphs.c b/src/daemon/graphs.c
index 2c0a6c1..071e06d 100644
--- a/src/daemon/graphs.c
+++ b/src/daemon/graphs.c
@@ -99,6 +99,7 @@ static const td_graph_impl* graph_impls[] = {
 	&knot_resolver_transports_graph,
 	&knot_resolver_responses_graph,
 	&knot_resolver_response_time_graph,
+	&knot_resolver_latency_graph,
 
 	// Unbound
 	&unbound_cache_performance_graph,
diff --git a/src/daemon/graphs/graph.h b/src/daemon/graphs/graph.h
index 3c7b4a5..e205fb8 100644
--- a/src/daemon/graphs/graph.h
+++ b/src/daemon/graphs/graph.h
@@ -292,6 +292,15 @@ static inline int __DRAW(td_args* args, const char* what, const char* field,
 
 #define COMPUTE_CDEF(args, cdef, ...)			SCRIPT(args, "CDEF:" cdef, ##__VA_ARGS__)
 
+#define COMPUTE_ADD(args, sum, object1, summand1, object2, summand2) \
+	do { \
+		COMPUTE_CDEF(args, FIELD "=" FIELD "," TOSTRING(summand2) ",+", \
+			FIELD_AND_OBJECT(sum, object1), \
+			FIELD_AND_OBJECT(summand1, object2) \
+		); \
+		VALUE_ALL(args, sum, object1); \
+	} while (0)
+
 #define COMPUTE_SUM(args, sum, object1, summand1, object2, summand2, object3) \
 	do { \
 		COMPUTE_CDEF(args, FIELD "=" FIELD "," FIELD ",+", \
@@ -321,6 +330,25 @@ static inline int __DRAW(td_args* args, const char* what, const char* field,
 		VALUE_ALL(args, product, object1); \
 	} while (0)
 
+#define COMPUTE_DIVIDE(args, fraction, object1, dividend, object2, divisor) \
+	do { \
+		COMPUTE_CDEF(args, FIELD "=" FIELD "," TOSTRING(divisor) ",/", \
+			FIELD_AND_OBJECT(fraction, object1), \
+			FIELD_AND_OBJECT(dividend, object2) \
+		); \
+		VALUE_ALL(args, fraction, object1); \
+	} while (0)
+
+#define COMPUTE_DIVIDE_BY(args, fraction, object1, dividend, object2, divisor, object3) \
+	do { \
+		COMPUTE_CDEF(args, FIELD "=" FIELD "," FIELD ",/", \
+			FIELD_AND_OBJECT(fraction, object1), \
+			FIELD_AND_OBJECT(dividend, object2), \
+			FIELD_AND_OBJECT(divisor,  object3) \
+		); \
+		VALUE_ALL(args, fraction, object1); \
+	} while (0)
+
 // Converts bytes to bits
 #define COMPUTE_BITS(args, bits, object, bytes)	\
 	COMPUTE_MULTIPLY(args, bits, object, bytes, object, 8)
@@ -344,15 +372,6 @@ static inline int __DRAW(td_args* args, const char* what, const char* field,
 		VALUE_ALL(args, FIELD_FAHRENHEIT(field), object); \
 	} while (0)
 
-#define COMPUTE_DIVIDE(args, fraction, object1, dividend, object2, divisor) \
-	do { \
-		COMPUTE_CDEF(args, FIELD "=" FIELD "," TOSTRING(divisor) ",/", \
-			FIELD_AND_OBJECT(fraction, object1), \
-			FIELD_AND_OBJECT(dividend, object2) \
-		); \
-		VALUE_ALL(args, fraction, object1); \
-	} while (0)
-
 #define COMPUTE_PERCENTAGE(args, field, object1, total, object2) \
 	do { \
 		COMPUTE_CDEF(args, FIELD "=100," FIELD ",*," FIELD ",/", \
diff --git a/src/daemon/graphs/knot-resolver.c b/src/daemon/graphs/knot-resolver.c
index bb4e322..1ec08e5 100644
--- a/src/daemon/graphs/knot-resolver.c
+++ b/src/daemon/graphs/knot-resolver.c
@@ -347,3 +347,51 @@ const td_graph_impl knot_resolver_response_time_graph = {
 	.lower_limit = 0,
 	.upper_limit = LONG_MAX,
 };
+
+// Latency
+
+static int knot_resolver_latency_title(td_ctx* ctx, td_graph* graph,
+		const char* object, char* title, size_t length) {
+	return __td_string_set(title, length, _("Latency"));
+}
+
+static int knot_resolver_latency_render(td_ctx* ctx, td_graph* graph,
+		const td_graph_render_options* options, td_args* args, const char* object) {
+	int r;
+
+	// Load all sources
+	r = td_graph_load_source(graph, args, "knot-resolver", NULL);
+	if (r < 0)
+		return r;
+
+	// Add one to the total so we won't divide by zero
+	COMPUTE_ADD(args, "answer_totalp1", NULL, "answer_total", NULL, 1);
+
+	// Compute average response time
+	COMPUTE_DIVIDE_BY(args, "latency_ms", NULL,
+		"answer_sum_ms", NULL, "answer_totalp1", NULL);
+
+	// Convert into seconds
+	COMPUTE_DIVIDE(args, "latency", NULL, "latency_ms", NULL, 1000);
+
+	// Header
+	PRINT_HEADER4(args, _("Current"), _("Average"), _("Minimum"), _("Maximum"));
+
+	// Draw the latency
+	DRAW_LINE_WITH_LABEL(args, 1, "latency", NULL, COLOR_LATENCY, 0, _("Latency"));
+	PRINT_CAMM(args, "latency", NULL, SECONDS_HIGHRES);
+
+	return 0;
+}
+
+const td_graph_impl knot_resolver_latency_graph = {
+	.name        = "KnotResolverLatency",
+	.can_render  = knot_resolver_can_render,
+	.render      = knot_resolver_latency_render,
+	.title       = knot_resolver_latency_title,
+	.vlabel      = td_graph_vlabel_seconds,
+
+	// Limits
+	.lower_limit = 0,
+	.upper_limit = LONG_MAX,
+};
diff --git a/src/daemon/graphs/knot-resolver.h b/src/daemon/graphs/knot-resolver.h
index 849c4c0..266cd2c 100644
--- a/src/daemon/graphs/knot-resolver.h
+++ b/src/daemon/graphs/knot-resolver.h
@@ -28,5 +28,6 @@ extern const td_graph_impl knot_resolver_cache_graph;
 extern const td_graph_impl knot_resolver_transports_graph;
 extern const td_graph_impl knot_resolver_responses_graph;
 extern const td_graph_impl knot_resolver_response_time_graph;
+extern const td_graph_impl knot_resolver_latency_graph;
 
 #endif /* TELEMETRY_GRAPH_KNOT_RESOLVER_H */