diff --git a/examples/kafka-single.yaml b/examples/kafka-single.yaml
index dc6653b..210dfd0 100644
--- a/examples/kafka-single.yaml
+++ b/examples/kafka-single.yaml
@@ -20,10 +20,12 @@
 # ex:
 #   helm install -f examples/kafka-single.yaml --version 0.8.8 -n cord-kafka incubator/kafka
 
-replicas: 1
-
+# ref: https://kafka.apache.org/documentation/#configuration
 configurationOverrides:
   "offsets.topic.replication.factor": 1
+  "log.retention.hours": 4
+
+replicas: 1
 
 persistence:
   enabled: false