From: Steinar H. Gunderson <sgunderson@bigfoot.com>
Date: Wed, 21 Jun 2017 19:50:37 +0000 (+0200)
Subject: Fix another Prometheus NaN problem.
X-Git-Tag: 1.6.1~29
X-Git-Url: https://git.sesse.net/?a=commitdiff_plain;h=6a52be5ea94241f6307a953788811c2f2ed2ac77;p=nageru

Fix another Prometheus NaN problem.
---

diff --git a/metrics.cpp b/metrics.cpp
index eae1e25..86c3d59 100644
--- a/metrics.cpp
+++ b/metrics.cpp
@@ -317,7 +317,13 @@ string Summary::serialize(Metrics::Laziness laziness, const string &name, const
 		vector<pair<string, string>> quantile_labels = labels;
 		quantile_labels.emplace_back("quantile", quantile_ss.str());
 
-		ss << Metrics::serialize_name(name, quantile_labels) << " " << quantile_and_value.second << "\n";
+		double val = quantile_and_value.second;;
+		if (isnan(val)) {
+			// Prometheus can't handle “-nan”.
+			ss << Metrics::serialize_name(name, quantile_labels) << " NaN\n";
+		} else {
+			ss << Metrics::serialize_name(name, quantile_labels) << " " << val << "\n";
+		}
 	}
 
 	ss << Metrics::serialize_name(name + "_sum", labels) << " " << sum.load() << "\n";