Broker suddenly got disconnected

############################# Socket Server Settings #############################

num.network.threads=3
num.io.threads=8
socket.send.buffer.bytes=102400
socket.receive.buffer.bytes=102400
socket.request.max.bytes=104857600

############################# Log Basics #############################

num.partitions=1
num.recovery.threads.per.data.dir=1

############################# Internal Topic Settings  #############################

offsets.topic.replication.factor=3
transaction.state.log.replication.factor=3
transaction.state.log.min.isr=2

############################# Log Retention Policy #############################
log.retention.hours=168
log.segment.bytes=1073741824
log.retention.check.interval.ms=300000


############################# Group Coordinator Settings #############################
group.initial.rebalance.delay.ms=0

############################# Zookeeper #############################

zookeeper.connection.timeout.ms=6000

broker.id=1
zookeeper.connect=zk1:2181,zk2:2181,zk3:2181
log.dirs=/data/kafka-node
advertised.listeners=PLAINTEXT://node1:9092

[2019-01-26 05:03:52,512] TRACE [Controller id=2] Checking need to trigger auto leader balancing (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] DEBUG [Controller id=2] Preferred replicas by broker Map(TOPICS->MAP) (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] DEBUG [Controller id=2] Topics not in preferred replica for broker 2 Map() (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] TRACE [Controller id=2] Leader imbalance ratio for broker 2 is 0.0 (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] DEBUG [Controller id=2] Topics not in preferred replica for broker 1 Map() (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] TRACE [Controller id=2] Leader imbalance ratio for broker 1 is 0.0 (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] DEBUG [Controller id=2] Topics not in preferred replica for broker 3 Map() (kafka.controller.KafkaController)
[2019-01-26 05:03:52,513] TRACE [Controller id=2] Leader imbalance ratio for broker 3 is 0.0 (kafka.controller.KafkaController)
[2019-01-26 05:08:52,513] TRACE [Controller id=2] Checking need to trigger auto leader balancing (kafka.controller.KafkaController)

[2019-01-26 05:02:05,564] INFO [ReplicaFetcher replicaId=3, leaderId=2, fetcherId=0] Error sending fetch request (sessionId=1637095899, epoch=21379644) to node 2: java.io.IOException: Connection to 2 was disconnected before the response was read. (org.apache.kafka.clients.FetchSessionHandler)
[2019-01-26 05:02:05,573] WARN [ReplicaFetcher replicaId=3, leaderId=2, fetcherId=0] Error in response for fetch request (type=FetchRequest, replicaId=3, maxWait=500, minBytes=1, maxBytes=10485760, fetchData={PlayerGameRounds-8=(offset=2171960, logStartOffset=1483356, maxBytes=1048576, currentLeaderEpoch=Optional[2])}, isolationLevel=READ_UNCOMMITTED, toForget=, metadata=(sessio
nId=1637095899, epoch=21379644)) (kafka.server.ReplicaFetcherThread)
java.io.IOException: Connection to 2 was disconnected before the response was read
        at org.apache.kafka.clients.NetworkClientUtils.sendAndReceive(NetworkClientUtils.java:97)
        at kafka.server.ReplicaFetcherBlockingSend.sendRequest(ReplicaFetcherBlockingSend.scala:97)
        at kafka.server.ReplicaFetcherThread.fetchFromLeader(ReplicaFetcherThread.scala:190)
        at kafka.server.AbstractFetcherThread.kafka$server$AbstractFetcherThread$$processFetchRequest(AbstractFetcherThread.scala:241)
        at kafka.server.AbstractFetcherThread$$anonfun$maybeFetch$1.apply(AbstractFetcherThread.scala:130)
        at kafka.server.AbstractFetcherThread$$anonfun$maybeFetch$1.apply(AbstractFetcherThread.scala:129)
        at scala.Option.foreach(Option.scala:257)
        at kafka.server.AbstractFetcherThread.maybeFetch(AbstractFetcherThread.scala:129)
        at kafka.server.AbstractFetcherThread.doWork(AbstractFetcherThread.scala:111)
        at kafka.utils.ShutdownableThread.run(ShutdownableThread.scala:82)
[2019-01-26 05:02:35,723] WARN Attempting to send response via channel for which there is no open connection, connection id node3:9092-node2:59988-1550 (kafka.network.Processor)
[2019-01-26 05:02:35,731] WARN Attempting to send response via channel for which there is no open connection, connection id node3:9092-node2:59986-1550 (kafka.network.Processor)
[2019-01-26 05:02:35,797] WARN Attempting to send response via channel for which there is no open connection, connection id node3:9092-node2:59494-1549 (kafka.network.Processor)
[2019-01-26 05:02:35,816] WARN Attempting to send response via channel for which there is no open connection, connection id node3:9092-node2:53268-1530 (kafka.network.Processor)
[2019-01-26 05:02:37,603] INFO [ReplicaFetcher replicaId=3, leaderId=2, fetcherId=0] Error sending fetch request (sessionId=1637095899, epoch=INITIAL) to node 2: java.io.IOException: Connection to 2 was disconnected before the response was read. (org.apache.kafka.clients.FetchSessionHandler)