fix message count calculation

Author: SiweiWang

dashboards/Kafka.json

@@ -73,7 +73,7 @@
           },
           "targets": [
             {
-              "expr": "kafka_log_log_value{topic=\"customer\"}",
+              "expr": "sum(kafka_log_log_value{ name=\"LogEndOffset\" , topic = \"customer\" }) - sum(kafka_log_log_value{ name=\"LogStartOffset\", topic = \"customer\" })",
               "intervalFactor": 2,
               "legendFormat": "",
               "metric": "",
@@ -154,7 +154,7 @@
           },
           "targets": [
             {
-              "expr": "kafka_log_log_value{topic=\"audit\"}",
+              "expr": "sum(kafka_log_log_value{ name=\"LogEndOffset\" , topic = \"audit\" }) - sum(kafka_log_log_value{ name=\"LogStartOffset\", topic = \"audit\" })",
               "intervalFactor": 2,
               "legendFormat": "",
               "metric": "",

prometheus-jmx-exporter/confd/templates/kafka.yml.tmpl

@@ -18,4 +18,5 @@ rules:
 - pattern : kafka.cluster<type=Partition, name=UnderReplicated, topic=(.+), partition=(.+)><>Value
 - pattern : kafka.utils<type=Throttler, name=cleaner-io><>OneMinuteRate
 - pattern : kafka.log<type=Log, name=LogEndOffset, topic=(.+), partition=(.+)><>Value
+- pattern : kafka.log<type=Log, name=LogStartOffset, topic=(.+), partition=(.+)><>Value
 - pattern : java.lang<type=(.*)>