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
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. If a password is not set access to the truststore is still available, but integrity checking is disabled.	password	null		high
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	""		medium
connections.max.idle.ms	Close idle connections after the number of milliseconds specified by this config.	long	300000		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	120000	[0,...]	medium
sasl.jaas.config	JAAS login context parameters for SASL connections in the format used by JAAS configuration files. JAAS configuration file format is described here. The format for the value is: ' (=)*;'	password	null		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
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.recording.level	The highest recording level for metrics.	string	INFO	[INFO, DEBUG]	low
metrics.sample.window.ms	The window of time a metrics sample is computed over.	long	30000	[0,...]	low
reconnect.backoff.max.ms	The maximum amount of time in milliseconds to wait when reconnectng to a broker that has repeatedly failed to connect. If provided, the backoff per host will increase exponentially for each consecutive connection failure, up to this maximum. After calculating the backoff increase, 20% random jitter is added to avoid connection storms.	long	1000	[0,...]	low
reconnect.backoff.ms	The base 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 connection attempts by the client to a broker.	long	50	[0,...]	low
retries	The maximum number of times to retry a call before failing it.	int	5	[0,...]	low
retry.backoff.ms	The amount of time to wait before attempting to retry a failed request. 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