Name	Description	Type	Default	Valid Values	Importance
bootstrap.servers	A list of host/port pairs to use for establishing the initial connection to the Kafka cluster. The client will make use of all servers irrespective of which servers are specified here for bootstrapping—this list only impacts the initial hosts used to discover the full set of servers. This list should be in the form host1:port1,host2:port2,.... Since these servers are just used for the initial connection to discover the full cluster membership (which may change dynamically), this list need not contain the full set of servers (you may want more than one, though, in case a server is down).	list			high
key.deserializer	Deserializer class for key that implements the Deserializer interface.	class			high
value.deserializer	Deserializer class for value that implements the Deserializer interface.	class			high
fetch.min.bytes	The minimum amount of data the server should return for a fetch request. If insufficient data is available the request will wait for that much data to accumulate before answering the request. The default setting of 1 byte means that fetch requests are answered as soon as a single byte of data is available or the fetch request times out waiting for data to arrive. Setting this to something greater than 1 will cause the server to wait for larger amounts of data to accumulate which can improve server throughput a bit at the cost of some additional latency.	int	1	[0,...]	high
group.id	A unique string that identifies the consumer group this consumer belongs to. This property is required if the consumer uses either the group management functionality by using subscribe(topic) or the Kafka-based offset management strategy.	string	""		high
heartbeat.interval.ms	The expected time between heartbeats to the consumer coordinator when using Kafka's group management facilities. Heartbeats are used to ensure that the consumer's session stays active and to facilitate rebalancing when new consumers join or leave the group. The value must be set lower than session.timeout.ms, but typically should be set no higher than 1/3 of that value. It can be adjusted even lower to control the expected time for normal rebalances.	int	3000		high
max.partition.fetch.bytes	The maximum amount of data per-partition the server will return. If the first message in the first non-empty partition of the fetch is larger than this limit, the message will still be returned to ensure that the consumer can make progress. The maximum message size accepted by the broker is defined via message.max.bytes (broker config) or max.message.bytes (topic config). See fetch.max.bytes for limiting the consumer request size	int	1048576	[0,...]	high
session.timeout.ms	The timeout used to detect consumer failures when using Kafka's group management facility. The consumer sends periodic heartbeats to indicate its liveness to the broker. If no heartbeats are received by the broker before the expiration of this session timeout, then the broker will remove this consumer from the group and initiate a rebalance. Note that the value must be in the allowable range as configured in the broker configuration by group.min.session.timeout.ms and group.max.session.timeout.ms.	int	10000		high
ssl.key.password	The password of the private key in the key store file. This is optional for client.	password	null		high
ssl.keystore.location	The location of the key store file. This is optional for client and can be used for two-way authentication for client.	string	null		high
ssl.keystore.password	The store password for the key store file. This is optional for client and only needed if ssl.keystore.location is configured.	password	null		high
ssl.truststore.location	The location of the trust store file.	string	null		high
ssl.truststore.password	The password for the trust store file.	password	null		high
auto.offset.reset	What to do when there is no initial offset in Kafka or if the current offset does not exist any more on the server (e.g. because that data has been deleted): earliest: automatically reset the offset to the earliest offset latest: automatically reset the offset to the latest offset none: throw exception to the consumer if no previous offset is found for the consumer's group anything else: throw exception to the consumer.	string	latest	[latest, earliest, none]	medium
connections.max.idle.ms	Close idle connections after the number of milliseconds specified by this config.	long	540000		medium
enable.auto.commit	If true the consumer's offset will be periodically committed in the background.	boolean	true		medium
exclude.internal.topics	Whether records from internal topics (such as offsets) should be exposed to the consumer. If set to true the only way to receive records from an internal topic is subscribing to it.	boolean	true		medium
fetch.max.bytes	The maximum amount of data the server should return for a fetch request. This is not an absolute maximum, if the first message in the first non-empty partition of the fetch is larger than this value, the message will still be returned to ensure that the consumer can make progress. The maximum message size accepted by the broker is defined via message.max.bytes (broker config) or max.message.bytes (topic config). Note that the consumer performs multiple fetches in parallel.	int	52428800	[0,...]	medium
max.poll.interval.ms	The maximum delay between invocations of poll() when using consumer group management. This places an upper bound on the amount of time that the consumer can be idle before fetching more records. If poll() is not called before expiration of this timeout, then the consumer is considered failed and the group will rebalance in order to reassign the partitions to another member.	int	300000	[1,...]	medium
max.poll.records	The maximum number of records returned in a single call to poll().	int	500	[1,...]	medium
partition.assignment.strategy	The class name of the partition assignment strategy that the client will use to distribute partition ownership amongst consumer instances when group management is used	list	[class org.apache.kafka.clients.consumer.RangeAssignor]		medium
receive.buffer.bytes	The size of the TCP receive buffer (SO_RCVBUF) to use when reading data. If the value is -1, the OS default will be used.	int	65536	[-1,...]	medium
request.timeout.ms	The configuration controls the maximum amount of time the client will wait for the response of a request. If the response is not received before the timeout elapses the client will resend the request if necessary or fail the request if retries are exhausted.	int	305000	[0,...]	medium
sasl.kerberos.service.name	The Kerberos principal name that Kafka runs as. This can be defined either in Kafka's JAAS config or in Kafka's config.	string	null		medium
sasl.mechanism	SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.	string	GSSAPI		medium
security.protocol	Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.	string	PLAINTEXT		medium
send.buffer.bytes	The size of the TCP send buffer (SO_SNDBUF) to use when sending data. If the value is -1, the OS default will be used.	int	131072	[-1,...]	medium
ssl.enabled.protocols	The list of protocols enabled for SSL connections.	list	[TLSv1.2, TLSv1.1, TLSv1]		medium
ssl.keystore.type	The file format of the key store file. This is optional for client.	string	JKS		medium
ssl.protocol	The SSL protocol used to generate the SSLContext. Default setting is TLS, which is fine for most cases. Allowed values in recent JVMs are TLS, TLSv1.1 and TLSv1.2. SSL, SSLv2 and SSLv3 may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities.	string	TLS		medium
ssl.provider	The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.	string	null		medium
ssl.truststore.type	The file format of the trust store file.	string	JKS		medium
auto.commit.interval.ms	The frequency in milliseconds that the consumer offsets are auto-committed to Kafka if enable.auto.commit is set to true.	int	5000	[0,...]	low
check.crcs	Automatically check the CRC32 of the records consumed. This ensures no on-the-wire or on-disk corruption to the messages occurred. This check adds some overhead, so it may be disabled in cases seeking extreme performance.	boolean	true		low
client.id	An id string to pass to the server when making requests. The purpose of this is to be able to track the source of requests beyond just ip/port by allowing a logical application name to be included in server-side request logging.	string	""		low
fetch.max.wait.ms	The maximum amount of time the server will block before answering the fetch request if there isn't sufficient data to immediately satisfy the requirement given by fetch.min.bytes.	int	500	[0,...]	low
interceptor.classes	A list of classes to use as interceptors. Implementing the ConsumerInterceptor interface allows you to intercept (and possibly mutate) records received by the consumer. By default, there are no interceptors.	list	null		low
metadata.max.age.ms	The period of time in milliseconds after which we force a refresh of metadata even if we haven't seen any partition leadership changes to proactively discover any new brokers or partitions.	long	300000	[0,...]	low
metric.reporters	A list of classes to use as metrics reporters. Implementing the MetricReporter interface allows plugging in classes that will be notified of new metric creation. The JmxReporter is always included to register JMX statistics.	list	[]		low
metrics.num.samples	The number of samples maintained to compute metrics.	int	2	[1,...]	low
metrics.sample.window.ms	The window of time a metrics sample is computed over.	long	30000	[0,...]	low
reconnect.backoff.ms	The amount of time to wait before attempting to reconnect to a given host. This avoids repeatedly connecting to a host in a tight loop. This backoff applies to all requests sent by the consumer to the broker.	long	50	[0,...]	low
retry.backoff.ms	The amount of time to wait before attempting to retry a failed request to a given topic partition. This avoids repeatedly sending requests in a tight loop under some failure scenarios.	long	100	[0,...]	low
sasl.kerberos.kinit.cmd	Kerberos kinit command path.	string	/usr/bin/kinit		low
sasl.kerberos.min.time.before.relogin	Login thread sleep time between refresh attempts.	long	60000		low
sasl.kerberos.ticket.renew.jitter	Percentage of random jitter added to the renewal time.	double	0.05		low
sasl.kerberos.ticket.renew.window.factor	Login thread will sleep until the specified window factor of time from last refresh to ticket's expiry has been reached, at which time it will try to renew the ticket.	double	0.8		low
ssl.cipher.suites	A list of cipher suites. This is a named combination of authentication, encryption, MAC and key exchange algorithm used to negotiate the security settings for a network connection using TLS or SSL network protocol. By default all the available cipher suites are supported.	list	null		low
ssl.endpoint.identification.algorithm	The endpoint identification algorithm to validate server hostname using server certificate.	string	null		low
ssl.keymanager.algorithm	The algorithm used by key manager factory for SSL connections. Default value is the key manager factory algorithm configured for the Java Virtual Machine.	string	SunX509		low
ssl.secure.random.implementation	The SecureRandom PRNG implementation to use for SSL cryptography operations.	string	null		low
ssl.trustmanager.algorithm	The algorithm used by trust manager factory for SSL connections. Default value is the trust manager factory algorithm configured for the Java Virtual Machine.	string	PKIX		low