bootstrap.servers
group.id
fetch.max.bytes   默认1M

max.poll.records  每次poll返回消息的最大条数，默认500
enable.auto.commit   自动提交 offset
auto.commit.interval.ms   每隔多久提交一次offset，默认 5000ms  
max.poll.interval.ms  默认300000ms 300秒 5分钟
这个很重要 ，消费处理时间 超过该值 会导致重平衡 

connection.max.idle.max
连接最大空闲时间， 建议 -1，不回收连接

auto.offset.reset
earliest    offset不存在，从头开始消费
latest      offset不存在，从新消息开始消费 ，默认
none        offset不存在 ，抛异常

session.timeout.ms
Coordinator 检测消费者失败的时间，在该时间内保持心跳即可
更小的值可以更快发现消费者崩溃，更快地开启重平衡，避免消费滞后，但这会导致频繁重平衡

heartbeat.interval.ms  
心跳时间间隔 ，应小于  session.timeout.ms


partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]


auto.commit.interval.ms = 5000
request.timeout.ms = 305000
connections.max.idle.ms = 540000
fetch.max.wait.ms = 500
heartbeat.interval.ms = 3000
reconnect.backoff.max.ms = 1000
reconnect.backoff.ms = 50
request.timeout.ms = 305000
retry.backoff.ms = 100
session.timeout.ms = 10000


isolation.level = read_uncommitted


全部参数及默认值

consumer运行时，会输出配置信息

INFO  org.apache.kafka.clients.consumer.ConsumerConfig -ConsumerConfig values: 
	auto.commit.interval.ms = 5000
	auto.offset.reset = latest
	bootstrap.servers = [127.0.0.1:9092]
	check.crcs = true
	client.id = 
	connections.max.idle.ms = 540000
	enable.auto.commit = true
	exclude.internal.topics = true
	fetch.max.bytes = 52428800
	fetch.max.wait.ms = 500
	fetch.min.bytes = 1
	group.id = kafkademo_test_group
	heartbeat.interval.ms = 3000
	interceptor.classes = []
	internal.leave.group.on.close = true
	isolation.level = read_uncommitted
	key.deserializer = class org.apache.kafka.common.serialization.StringDeserializer
	max.partition.fetch.bytes = 1048576
	max.poll.interval.ms = 300000
	max.poll.records = 500
	metadata.max.age.ms = 300000
	metric.reporters = []
	metrics.num.samples = 2
	metrics.recording.level = INFO
	metrics.sample.window.ms = 30000
	partition.assignment.strategy = [class org.apache.kafka.clients.consumer.RangeAssignor]
	receive.buffer.bytes = 65536
	reconnect.backoff.max.ms = 1000
	reconnect.backoff.ms = 50
	request.timeout.ms = 305000
	retry.backoff.ms = 100
	sasl.jaas.config = null
	sasl.kerberos.kinit.cmd = /usr/bin/kinit
	sasl.kerberos.min.time.before.relogin = 60000
	sasl.kerberos.service.name = null
	sasl.kerberos.ticket.renew.jitter = 0.05
	sasl.kerberos.ticket.renew.window.factor = 0.8
	sasl.mechanism = GSSAPI
	security.protocol = PLAINTEXT
	send.buffer.bytes = 131072
	session.timeout.ms = 10000
	ssl.cipher.suites = null
	ssl.enabled.protocols = [TLSv1.2, TLSv1.1, TLSv1]
	ssl.endpoint.identification.algorithm = null
	ssl.key.password = null
	ssl.keymanager.algorithm = SunX509
	ssl.keystore.location = null
	ssl.keystore.password = null
	ssl.keystore.type = JKS
	ssl.protocol = TLS
	ssl.provider = null
	ssl.secure.random.implementation = null
	ssl.trustmanager.algorithm = PKIX
	ssl.truststore.location = null
	ssl.truststore.password = null
	ssl.truststore.type = JKS
	value.deserializer = class org.apache.kafka.common.serialization.StringDeserializer



例子代码
https://gitee.com/dyyx/kafkademo/blob/master/src/main/java/dyyx/ConsumerTest.java