From 0e55dfbb3edf49503c80bd832b37bf9be7d39356 Mon Sep 17 00:00:00 2001
From: Christian Tzolov <christian.tzolov@gmail.com>
Date: Mon, 7 Dec 2020 13:25:58 +0100
Subject: [PATCH] Improve analytcs meter tas consistency

---
 .../fn/consumer/analytics/AnalyticsConsumerConfiguration.java | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/consumer/analytics-consumer/src/main/java/org/springframework/cloud/fn/consumer/analytics/AnalyticsConsumerConfiguration.java b/consumer/analytics-consumer/src/main/java/org/springframework/cloud/fn/consumer/analytics/AnalyticsConsumerConfiguration.java
index 25e0a869..b35f2b01 100644
--- a/consumer/analytics-consumer/src/main/java/org/springframework/cloud/fn/consumer/analytics/AnalyticsConsumerConfiguration.java
+++ b/consumer/analytics-consumer/src/main/java/org/springframework/cloud/fn/consumer/analytics/AnalyticsConsumerConfiguration.java
@@ -111,7 +111,9 @@ public class AnalyticsConsumerConfiguration {
 	 */
 	protected List<String> toList(Object value) {
 		if (value == null) {
-			return Collections.emptyList();
+			// Ensure that the tag is present in the meter metrics, even if empty.
+			// TSDB as Prometheus do not tolerate same meters to have different tags signatures.
+			return Collections.singletonList("n.a");
 		}
 
 		if ((value instanceof Collection) || ObjectUtils.isArray(value)) {