Kafka - Added session metrics

kafka/datadog_checks/kafka/data/metrics.yaml

@@ -664,3 +664,21 @@ jmx_metrics:
           Count:
             metric_type: rate
             alias: kafka.session.zookeeper.sync.rate
+
+    #
+    # Session stats
+    #
+    - include:
+        domain: 'kafka.server'
+        bean: 'kafka.server:type=FetchSessionCache,name=NumIncrementalFetchSessions'
+        attribute:
+          Value:
+            metric_type: gauge
+            alias: kafka.session.fetch.count
+    - include:
+        domain: 'kafka.server'
+        bean: 'kafka.server:type=FetchSessionCache,name=IncrementalFetchSessionEvictionsPerSec'
+        attribute:
+          Count:
+            alias: kafka.session.fetch.eviction
+            metric_type: rate

kafka/metadata.csv

@@ -85,3 +85,5 @@ kafka.topic.messages_in.rate,gauge,10,message,,Incoming message rate by topic,0,
 kafka.topic.net.bytes_out.rate,gauge,10,byte,second,Outgoing byte rate by topic.,0,kafka,topic bytes out
 kafka.topic.net.bytes_in.rate,gauge,10,byte,second,Incoming byte rate by topic.,0,kafka,topic bytes in
 kafka.topic.net.bytes_rejected.rate,gauge,10,byte,second,Rejected byte rate by topic.,-1,kafka,topic bytes rejected
+kafka.session.fetch.count,gauge,10,,,Number of fetch sessions.,0,kafka,fetch sessions
+kafka.session.fetch.eviction,gauge,10,event,second,Eviction rate of fetch session.,0,kafka,eviction session rate

kafka/tests/common.py

@@ -59,4 +59,7 @@
     "kafka.session.zookeeper.expire.rate",
     "kafka.session.zookeeper.readonly.rate",
     "kafka.session.zookeeper.sync.rate",
+    # Session
+    "kafka.session.fetch.count",
+    "kafka.session.fetch.eviction",
 ]