Revert "Revert "Warn if config changes without generation changing""

1 files changed, 3 insertions, 1 deletions

diff --git a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
index caa11b211ac..5d720a74b15 100644
--- a/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
+++ b/config/src/main/java/com/yahoo/config/subscription/impl/ConfigSubscription.java
@@ -206,7 +206,9 @@ public abstract class ConfigSubscription<T extends ConfigInstance> {
             int sizeHint = 500;
             log.log(Level.WARNING, "Config has changed unexpectedly for " + key + ", generation " + generation +
                     ", config in state :" + generator.makeSnippet(previousConfig.toString(), sizeHint) + ", new config: " +
-                    generator.makeSnippet(config.toString(), sizeHint));
+                    generator.makeSnippet(config.toString(), sizeHint) +
+                    ". This likely happened because config changed on a previous generation" +
+                    ", look for earlier entry in log with warning about config changing without a change in config generation.");
         }
         this.config.set(new ConfigState<>(true, generation, applyOnRestart, configChanged, config, payloadChecksums));
     }