Kafka Connect Configuration Reference for Confluent Platform¶

This topic provides configuration parameters available for Confluent Platform. The parameters are organized by order of importance, ranked from high to low.

Search by configuration property name¶

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config.storage.topic¶

The name of the Kafka topic where connector configurations are stored

Type:	string
Default:
Valid Values:
Importance:	high

group.id¶

A unique string that identifies the Connect cluster group this worker belongs to.

Type:	string
Default:
Valid Values:
Importance:	high

key.converter¶

Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the keys in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.

Type:	class
Default:
Valid Values:
Importance:	high

offset.storage.topic¶

The name of the Kafka topic where source connector offsets are stored

Type:	string
Default:
Valid Values:
Importance:	high

status.storage.topic¶

The name of the Kafka topic where connector and task status are stored

Type:	string
Default:
Valid Values:
Importance:	high

value.converter¶

Converter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro.

Type:	class
Default:
Valid Values:
Importance:	high

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).

Type:	list
Default:	localhost:9092
Valid Values:
Importance:	high

exactly.once.source.support¶

Whether to enable exactly-once support for source connectors in the cluster by using transactions to write source records and their source offsets, and by proactively fencing out old task generations before bringing up new ones.To enable exactly-once source support on a new cluster, set this property to ‘enabled’. To enable support on an existing cluster, first set to ‘preparing’ on every worker in the cluster, then set to ‘enabled’. A rolling upgrade may be used for both changes. For more information on this feature, see the exactly-once source support documentation.

Type:	string
Default:	disabled
Valid Values:	(case insensitive) [DISABLED, ENABLED, PREPARING]
Importance:	high

heartbeat.interval.ms¶

The expected time between heartbeats to the group coordinator when using Kafka’s group management facilities. Heartbeats are used to ensure that the worker’s session stays active and to facilitate rebalancing when new members 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.

Type:	int
Default:	3000 (3 seconds)
Valid Values:
Importance:	high

rebalance.timeout.ms¶

The maximum allowed time for each worker to join the group once a rebalance has begun. This is basically a limit on the amount of time needed for all tasks to flush any pending data and commit offsets. If the timeout is exceeded, then the worker will be removed from the group, which will cause offset commit failures.

Type:	int
Default:	60000 (1 minute)
Valid Values:
Importance:	high

session.timeout.ms¶

The timeout used to detect worker failures. The worker 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 the worker 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.

Type:	int
Default:	10000 (10 seconds)
Valid Values:
Importance:	high

ssl.key.password¶

The password of the private key in the key store file or the PEM key specified in ‘ssl.keystore.key’.

Type:	password
Default:	null
Valid Values:
Importance:	high

ssl.keystore.certificate.chain¶

Certificate chain in the format specified by ‘ssl.keystore.type’. Default SSL engine factory supports only PEM format with a list of X.509 certificates

Type:	password
Default:	null
Valid Values:
Importance:	high

ssl.keystore.key¶

Private key in the format specified by ‘ssl.keystore.type’. Default SSL engine factory supports only PEM format with PKCS#8 keys. If the key is encrypted, key password must be specified using ‘ssl.key.password’

Type:	password
Default:	null
Valid Values:
Importance:	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.

Type:	string
Default:	null
Valid Values:
Importance:	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. Key store password is not supported for PEM format.

Type:	password
Default:	null
Valid Values:
Importance:	high

ssl.truststore.certificates¶

Trusted certificates in the format specified by ‘ssl.truststore.type’. Default SSL engine factory supports only PEM format with X.509 certificates.

Type:	password
Default:	null
Valid Values:
Importance:	high

ssl.truststore.location¶

The location of the trust store file.

Type:	string
Default:	null
Valid Values:
Importance:	high

ssl.truststore.password¶

The password for the trust store file. If a password is not set, trust store file configured will still be used, but integrity checking is disabled. Trust store password is not supported for PEM format.

Type:	password
Default:	null
Valid Values:
Importance:	high

client.dns.lookup¶

Controls how the client uses DNS lookups. If set to use_all_dns_ips, connect to each returned IP address in sequence until a successful connection is established. After a disconnection, the next IP is used. Once all IPs have been used once, the client resolves the IP(s) from the hostname again (both the JVM and the OS cache DNS name lookups, however). If set to resolve_canonical_bootstrap_servers_only, resolve each bootstrap address into a list of canonical names. After the bootstrap phase, this behaves the same as use_all_dns_ips.

Type:	string
Default:	use_all_dns_ips
Valid Values:	[use_all_dns_ips, resolve_canonical_bootstrap_servers_only]
Importance:	medium

connections.max.idle.ms¶

Close idle connections after the number of milliseconds specified by this config.

Type:	long
Default:	540000 (9 minutes)
Valid Values:
Importance:	medium

connector.client.config.override.policy¶

Class name or alias of implementation of ConnectorClientConfigOverridePolicy. Defines what client configurations can be overridden by the connector. The default implementation is All, meaning connector configurations can override all client properties. The other possible policies in the framework include None to disallow connectors from overriding client properties, and Principal to allow connectors to override only client principals.

Type:	string
Default:	All
Valid Values:
Importance:	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.

Type:	int
Default:	32768 (32 kibibytes)
Valid Values:	[-1,…]
Importance:	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.

Type:	int
Default:	40000 (40 seconds)
Valid Values:	[0,…]
Importance:	medium

sasl.client.callback.handler.class¶

The fully qualified name of a SASL client callback handler class that implements the AuthenticateCallbackHandler interface.

Type:	class
Default:	null
Valid Values:
Importance:	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: loginModuleClass controlFlag (optionName=optionValue)*;. For brokers, the config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.jaas.config=com.example.ScramLoginModule required;

Type:	password
Default:	null
Valid Values:
Importance:	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.

Type:	string
Default:	null
Valid Values:
Importance:	medium

sasl.login.callback.handler.class¶

The fully qualified name of a SASL login callback handler class that implements the AuthenticateCallbackHandler interface. For brokers, login callback handler config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.callback.handler.class=com.example.CustomScramLoginCallbackHandler

Type:	class
Default:	null
Valid Values:
Importance:	medium

sasl.login.class¶

The fully qualified name of a class that implements the Login interface. For brokers, login config must be prefixed with listener prefix and SASL mechanism name in lower-case. For example, listener.name.sasl_ssl.scram-sha-256.sasl.login.class=com.example.CustomScramLogin

Type:	class
Default:	null
Valid Values:
Importance:	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.

Type:	string
Default:	GSSAPI
Valid Values:
Importance:	medium

sasl.oauthbearer.jwks.endpoint.url¶

The OAuth/OIDC provider URL from which the provider’s JWKS (JSON Web Key Set) can be retrieved. The URL can be HTTP(S)-based or file-based. If the URL is HTTP(S)-based, the JWKS data will be retrieved from the OAuth/OIDC provider via the configured URL on broker startup. All then-current keys will be cached on the broker for incoming requests. If an authentication request is received for a JWT that includes a “kid” header claim value that isn’t yet in the cache, the JWKS endpoint will be queried again on demand. However, the broker polls the URL every sasl.oauthbearer.jwks.endpoint.refresh.ms milliseconds to refresh the cache with any forthcoming keys before any JWT requests that include them are received. If the URL is file-based, the broker will load the JWKS file from a configured location on startup. In the event that the JWT includes a “kid” header value that isn’t in the JWKS file, the broker will reject the JWT and authentication will fail.

Type:	string
Default:	null
Valid Values:
Importance:	medium

sasl.oauthbearer.token.endpoint.url¶

The URL for the OAuth/OIDC identity provider. If the URL is HTTP(S)-based, it is the issuer’s token endpoint URL to which requests will be made to login based on the configuration in sasl.jaas.config. If the URL is file-based, it specifies a file containing an access token (in JWT serialized form) issued by the OAuth/OIDC identity provider to use for authorization.

Type:	string
Default:	null
Valid Values:
Importance:	medium

security.protocol¶

Protocol used to communicate with brokers. Valid values are: PLAINTEXT, SSL, SASL_PLAINTEXT, SASL_SSL.

Type:	string
Default:	PLAINTEXT
Valid Values:	(case insensitive) [SASL_SSL, PLAINTEXT, SSL, SASL_PLAINTEXT]
Importance:	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.

Type:	int
Default:	131072 (128 kibibytes)
Valid Values:	[-1,…]
Importance:	medium

ssl.enabled.protocols¶

The list of protocols enabled for SSL connections. The default is ‘TLSv1.2,TLSv1.3’ when running with Java 11 or newer, ‘TLSv1.2’ otherwise. With the default value for Java 11, clients and servers will prefer TLSv1.3 if both support it and fallback to TLSv1.2 otherwise (assuming both support at least TLSv1.2). This default should be fine for most cases. Also see the config documentation for ssl.protocol.

Type:	list
Default:	TLSv1.2
Valid Values:
Importance:	medium

ssl.keystore.type¶

The file format of the key store file. This is optional for client. The values currently supported by the default ssl.engine.factory.class are [JKS, PKCS12, PEM].

Type:	string
Default:	JKS
Valid Values:
Importance:	medium

ssl.protocol¶

The SSL protocol used to generate the SSLContext. The default is ‘TLSv1.3’ when running with Java 11 or newer, ‘TLSv1.2’ otherwise. This value should be fine for most use cases. Allowed values in recent JVMs are ‘TLSv1.2’ and ‘TLSv1.3’. ‘TLS’, ‘TLSv1.1’, ‘SSL’, ‘SSLv2’ and ‘SSLv3’ may be supported in older JVMs, but their usage is discouraged due to known security vulnerabilities. With the default value for this config and ‘ssl.enabled.protocols’, clients will downgrade to ‘TLSv1.2’ if the server does not support ‘TLSv1.3’. If this config is set to ‘TLSv1.2’, clients will not use ‘TLSv1.3’ even if it is one of the values in ssl.enabled.protocols and the server only supports ‘TLSv1.3’.

Type:	string
Default:	TLSv1.2
Valid Values:
Importance:	medium

ssl.provider¶

The name of the security provider used for SSL connections. Default value is the default security provider of the JVM.

Type:	string
Default:	null
Valid Values:
Importance:	medium

ssl.truststore.type¶

The file format of the trust store file. The values currently supported by the default ssl.engine.factory.class are [JKS, PKCS12, PEM].

Type:	string
Default:	JKS
Valid Values:
Importance:	medium

worker.sync.timeout.ms¶

When the worker is out of sync with other workers and needs to resynchronize configurations, wait up to this amount of time before giving up, leaving the group, and waiting a backoff period before rejoining.

Type:	int
Default:	3000 (3 seconds)
Valid Values:
Importance:	medium

worker.unsync.backoff.ms¶

When the worker is out of sync with other workers and fails to catch up within worker.sync.timeout.ms, leave the Connect cluster for this long before rejoining.

Type:	int
Default:	300000 (5 minutes)
Valid Values:
Importance:	medium

access.control.allow.methods¶

Sets the methods supported for cross origin requests by setting the Access-Control-Allow-Methods header. The default value of the Access-Control-Allow-Methods header allows cross origin requests for GET, POST and HEAD.

Type:	string
Default:	“”
Valid Values:
Importance:	low

access.control.allow.origin¶

Value to set the Access-Control-Allow-Origin header to for REST API requests.To enable cross origin access, set this to the domain of the application that should be permitted to access the API, or ‘*’ to allow access from any domain. The default value only allows access from the domain of the REST API.

Type:	string
Default:	“”
Valid Values:
Importance:	low

admin.listeners¶

List of comma-separated URIs the Admin REST API will listen on. The supported protocols are HTTP and HTTPS. An empty or blank string will disable this feature. The default behavior is to use the regular listener (specified by the ‘listeners’ property).

Type:	list
Default:	null
Valid Values:	List of comma-separated URLs, ex: http://localhost:8080,https://localhost:8443.
Importance:	low

auto.include.jmx.reporter¶

Deprecated. Whether to automatically include JmxReporter even if it’s not listed in metric.reporters. This configuration will be removed in Kafka 4.0, users should instead include org.apache.kafka.common.metrics.JmxReporter in metric.reporters in order to enable the JmxReporter.

Type:	boolean
Default:	true
Valid Values:
Importance:	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.

Type:	string
Default:	“”
Valid Values:
Importance:	low

config.providers¶

Comma-separated names of ConfigProvider classes, loaded and used in the order specified. Implementing the interface ConfigProvider allows you to replace variable references in connector configurations, such as for externalized secrets.

Type:	list
Default:	“”
Valid Values:
Importance:	low

config.storage.replication.factor¶

Replication factor used when creating the configuration storage topic

Type:	short
Default:	3
Valid Values:	Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker’s default
Importance:	low

connect.protocol¶

Compatibility mode for Kafka Connect Protocol

Type:	string
Default:	sessioned
Valid Values:	[eager, compatible, sessioned]
Importance:	low

enable.fips¶

Enable FIPS mode on the server. If FIPS mode is enabled, worker listener security protocols, TLS versions and cipher suites and rest protocols will be validated based on FIPS compliance requirement.

Type:	boolean
Default:	false
Valid Values:
Importance:	low

header.converter¶

HeaderConverter class used to convert between Kafka Connect format and the serialized form that is written to Kafka. This controls the format of the header values in messages written to or read from Kafka, and since this is independent of connectors it allows any connector to work with any serialization format. Examples of common formats include JSON and Avro. By default, the SimpleHeaderConverter is used to serialize header values to strings and deserialize them by inferring the schemas.

Type:	class
Default:	org.apache.kafka.connect.storage.SimpleHeaderConverter
Valid Values:
Importance:	low

inter.worker.key.generation.algorithm¶

The algorithm to use for generating internal request keys. The algorithm ‘HmacSHA256’ will be used as a default on JVMs that support it; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.

Type:	string
Default:	HmacSHA256
Valid Values:	Any KeyGenerator algorithm supported by the worker JVM
Importance:	low

inter.worker.key.size¶

The size of the key to use for signing internal requests, in bits. If null, the default key size for the key generation algorithm will be used.

Type:	int
Default:	null
Valid Values:
Importance:	low

inter.worker.key.ttl.ms¶

The TTL of generated session keys used for internal request validation (in milliseconds)

Type:	int
Default:	3600000 (1 hour)
Valid Values:	[0,…,2147483647]
Importance:	low

inter.worker.signature.algorithm¶

The algorithm used to sign internal requestsThe algorithm ‘inter.worker.signature.algorithm’ will be used as a default on JVMs that support it; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.

Type:	string
Default:	HmacSHA256
Valid Values:	Any MAC algorithm supported by the worker JVM
Importance:	low

inter.worker.verification.algorithms¶

A list of permitted algorithms for verifying internal requests, which must include the algorithm used for the inter.worker.signature.algorithm property. The algorithm(s) ‘[HmacSHA256]’ will be used as a default on JVMs that provide them; on other JVMs, no default is used and a value for this property must be manually specified in the worker config.

Type:	list
Default:	HmacSHA256
Valid Values:	A list of one or more MAC algorithms, each supported by the worker JVM
Importance:	low

listeners¶

List of comma-separated URIs the REST API will listen on. The supported protocols are HTTP and HTTPS. Specify hostname as 0.0.0.0 to bind to all interfaces. Leave hostname empty to bind to default interface. Examples of legal listener lists: HTTP://myhost:8083,HTTPS://myhost:8084

Type:	list
Default:	http://:8083
Valid Values:	List of comma-separated URLs, ex: http://localhost:8080,https://localhost:8443.
Importance:	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.

Type:	long
Default:	300000 (5 minutes)
Valid Values:	[0,…]
Importance:	low

metadata.recovery.strategy¶

Controls how the client recovers when none of the brokers known to it is available. If set to none, the client fails. If set to rebootstrap, the client repeats the bootstrap process using bootstrap.servers. Rebootstrapping is useful when a client communicates with brokers so infrequently that the set of brokers may change entirely before the client refreshes metadata. Metadata recovery is triggered when all last-known brokers appear unavailable simultaneously. Brokers appear unavailable when disconnected and no current retry attempt is in-progress. Consider increasing reconnect.backoff.ms and reconnect.backoff.max.ms and decreasing socket.connection.setup.timeout.ms and socket.connection.setup.timeout.max.ms for the client.

Type:	string
Default:	none
Valid Values:	(case insensitive) [REBOOTSTRAP, NONE]
Importance:	low

metric.reporters¶

A list of classes to use as metrics reporters. Implementing the org.apache.kafka.common.metrics.MetricsReporter interface allows plugging in classes that will be notified of new metric creation. The JmxReporter is always included to register JMX statistics.

Type:	list
Default:	“”
Valid Values:
Importance:	low

metrics.num.samples¶

The number of samples maintained to compute metrics.

Type:	int
Default:	2
Valid Values:	[1,…]
Importance:	low

metrics.recording.level¶

The highest recording level for metrics.

Type:	string
Default:	INFO
Valid Values:	[INFO, DEBUG]
Importance:	low

metrics.sample.window.ms¶

The window of time a metrics sample is computed over.

Type:	long
Default:	30000 (30 seconds)
Valid Values:	[0,…]
Importance:	low

offset.flush.interval.ms¶

Interval at which to try committing offsets for tasks.

Type:	long
Default:	60000 (1 minute)
Valid Values:
Importance:	low

offset.flush.timeout.ms¶

Maximum number of milliseconds to wait for records to flush and partition offset data to be committed to offset storage before cancelling the process and restoring the offset data to be committed in a future attempt. This property has no effect for source connectors running with exactly-once support.

Type:	long
Default:	5000 (5 seconds)
Valid Values:
Importance:	low

offset.storage.partitions¶

The number of partitions used when creating the offset storage topic

Type:	int
Default:	25
Valid Values:	Positive number, or -1 to use the broker’s default
Importance:	low

offset.storage.replication.factor¶

Replication factor used when creating the offset storage topic

Type:	short
Default:	3
Valid Values:	Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker’s default
Importance:	low

plugin.discovery¶

Method to use to discover plugins present in the classpath and plugin.path configuration. This can be one of multiple values with the following meanings:* only_scan: Discover plugins only by reflection. Plugins which are not discoverable by ServiceLoader will not impact worker startup.* hybrid_warn: Discover plugins reflectively and by ServiceLoader. Plugins which are not discoverable by ServiceLoader will print warnings during worker startup.* hybrid_fail: Discover plugins reflectively and by ServiceLoader. Plugins which are not discoverable by ServiceLoader will cause worker startup to fail.* service_load: Discover plugins only by ServiceLoader. Faster startup than other modes. Plugins which are not discoverable by ServiceLoader may not be usable.

Type:	string
Default:	hybrid_warn
Valid Values:	(case insensitive) [ONLY_SCAN, SERVICE_LOAD, HYBRID_WARN, HYBRID_FAIL]
Importance:	low

plugin.path¶

List of paths separated by commas (,) that contain plugins (connectors, converters, transformations). The list should consist of top level directories that include any combination of: a) directories immediately containing jars with plugins and their dependenciesb) uber-jars with plugins and their dependenciesc) directories immediately containing the package directory structure of classes of plugins and their dependenciesNote: symlinks will be followed to discover dependencies or plugins.Examples: plugin.path=/usr/local/share/java,/usr/local/share/kafka/plugins,/opt/connectorsDo not use config provider variables in this property, since the raw path is used by the worker’s scanner before config providers are initialized and used to replace variables.

Type:	list
Default:	null
Valid Values:
Importance:	low

reconnect.backoff.max.ms¶

The maximum amount of time in milliseconds to wait when reconnecting 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.

Type:	long
Default:	1000 (1 second)
Valid Values:	[0,…]
Importance:	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. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the reconnect.backoff.max.ms value.

Type:	long
Default:	50
Valid Values:	[0,…]
Importance:	low

response.http.headers.config¶

Rules for REST API HTTP response headers

Type:	string
Default:	“”
Valid Values:	Comma-separated header rules, where each header rule is of the form ‘[action] [header name]:[header value]’ and optionally surrounded by double quotes if any part of a header rule contains a comma
Importance:	low

rest.advertised.host.name¶

If this is set, this is the hostname that will be given out to other workers to connect to.

Type:	string
Default:	null
Valid Values:
Importance:	low

rest.advertised.listener¶

Sets the advertised listener (HTTP or HTTPS) which will be given to other workers to use.

Type:	string
Default:	null
Valid Values:
Importance:	low

rest.advertised.port¶

If this is set, this is the port that will be given out to other workers to connect to.

Type:	int
Default:	null
Valid Values:
Importance:	low

rest.extension.classes¶

Comma-separated names of ConnectRestExtension classes, loaded and called in the order specified. Implementing the interface ConnectRestExtension allows you to inject into Connect’s REST API user defined resources like filters. Typically used to add custom capability like logging, security, etc.

Type:	list
Default:	“”
Valid Values:
Importance:	low

rest.servlet.initializor.classes¶

Defines one or more initializer for the rest endpoint’s ServletContextHandler. Each initializer must implement Consumer. It will be called to perform initialization of the handler, in order. This is an internal feature and subject to change, including changes to the Jetty version .. list-table:

* - Type:
  - list
* - Default:
  - ""
* - Valid Values:
  -
* - Importance:
  - low

retry.backoff.max.ms¶

The maximum amount of time in milliseconds to wait when retrying a request to the broker that has repeatedly failed. If provided, the backoff per client will increase exponentially for each failed request, up to this maximum. To prevent all clients from being synchronized upon retry, a randomized jitter with a factor of 0.2 will be applied to the backoff, resulting in the backoff falling within a range between 20% below and 20% above the computed value. If retry.backoff.ms is set to be higher than retry.backoff.max.ms, then retry.backoff.max.ms will be used as a constant backoff from the beginning without any exponential increase

Type:	long
Default:	1000 (1 second)
Valid Values:	[0,…]
Importance:	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. This value is the initial backoff value and will increase exponentially for each failed request, up to the retry.backoff.max.ms value.

Type:	long
Default:	100
Valid Values:	[0,…]
Importance:	low

sasl.kerberos.kinit.cmd¶

Kerberos kinit command path.

Type:	string
Default:	/usr/bin/kinit
Valid Values:
Importance:	low

sasl.kerberos.min.time.before.relogin¶

Login thread sleep time between refresh attempts.

Type:	long
Default:	60000
Valid Values:
Importance:	low

sasl.kerberos.ticket.renew.jitter¶

Percentage of random jitter added to the renewal time.

Type:	double
Default:	0.05
Valid Values:
Importance:	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.

Type:	double
Default:	0.8
Valid Values:
Importance:	low

sasl.login.refresh.buffer.seconds¶

The amount of buffer time before credential expiration to maintain when refreshing a credential, in seconds. If a refresh would otherwise occur closer to expiration than the number of buffer seconds then the refresh will be moved up to maintain as much of the buffer time as possible. Legal values are between 0 and 3600 (1 hour); a default value of 300 (5 minutes) is used if no value is specified. This value and sasl.login.refresh.min.period.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.

Type:	short
Default:	300
Valid Values:	[0,…,3600]
Importance:	low

sasl.login.refresh.min.period.seconds¶

The desired minimum time for the login refresh thread to wait before refreshing a credential, in seconds. Legal values are between 0 and 900 (15 minutes); a default value of 60 (1 minute) is used if no value is specified. This value and sasl.login.refresh.buffer.seconds are both ignored if their sum exceeds the remaining lifetime of a credential. Currently applies only to OAUTHBEARER.

Type:	short
Default:	60
Valid Values:	[0,…,900]
Importance:	low

sasl.login.refresh.window.factor¶

Login refresh thread will sleep until the specified window factor relative to the credential’s lifetime has been reached, at which time it will try to refresh the credential. Legal values are between 0.5 (50%) and 1.0 (100%) inclusive; a default value of 0.8 (80%) is used if no value is specified. Currently applies only to OAUTHBEARER.

Type:	double
Default:	0.8
Valid Values:	[0.5,…,1.0]
Importance:	low

sasl.login.refresh.window.jitter¶

The maximum amount of random jitter relative to the credential’s lifetime that is added to the login refresh thread’s sleep time. Legal values are between 0 and 0.25 (25%) inclusive; a default value of 0.05 (5%) is used if no value is specified. Currently applies only to OAUTHBEARER.

Type:	double
Default:	0.05
Valid Values:	[0.0,…,0.25]
Importance:	low

sasl.login.retry.backoff.max.ms¶

The (optional) value in milliseconds for the maximum wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.

Type:	long
Default:	10000 (10 seconds)
Valid Values:
Importance:	low

sasl.login.retry.backoff.ms¶

The (optional) value in milliseconds for the initial wait between login attempts to the external authentication provider. Login uses an exponential backoff algorithm with an initial wait based on the sasl.login.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.login.retry.backoff.max.ms setting. Currently applies only to OAUTHBEARER.

Type:	long
Default:	100
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.audience¶

The value to be added to the Audience claim “aud” which will be included in the client assertion created locally

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.expiration¶

The (Optional) expiration time for the client assertion in minutesThe default value is 5 minutes

Type:	int
Default:	5
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.include.jti.claim¶

The (optional) setting for specifying whether to include jti claim or not

Type:	boolean
Default:	false
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.include.nbf.claim¶

The (optional) setting for specifying whether to include “not before” (nbf) claim or notIf set to true, nbf claim with (current time - 1 minute) will be included in the client assertion

Type:	boolean
Default:	false
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.issuer¶

The value to be added to the Issuer claim “iss” which will be included in the client assertion created locally

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.location¶

The location/path on disc at which a signed client assertion is presentThis will be passed directly to the token endpoint.

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.private.key¶

The location for the private key to be used for signing client assertion in PEM formatRequired for local client assertion creation

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.private.key.passphrase¶

The passphrase required for decrypting the private key (in case of PKCS#8 format pem file)

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clientassertion.subject¶

The value to be added to the Subject claim “sub” which will be included in the client assertion created locally

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.clock.skew.seconds¶

The (optional) value in seconds to allow for differences between the time of the OAuth/OIDC identity provider and the broker.

Type:	int
Default:	30
Valid Values:
Importance:	low

sasl.oauthbearer.expected.audience¶

The (optional) comma-delimited setting for the broker to use to verify that the JWT was issued for one of the expected audiences. The JWT will be inspected for the standard OAuth “aud” claim and if this value is set, the broker will match the value from JWT’s “aud” claim to see if there is an exact match. If there is no match, the broker will reject the JWT and authentication will fail.

Type:	list
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.expected.issuer¶

The (optional) setting for the broker to use to verify that the JWT was created by the expected issuer. The JWT will be inspected for the standard OAuth “iss” claim and if this value is set, the broker will match it exactly against what is in the JWT’s “iss” claim. If there is no match, the broker will reject the JWT and authentication will fail.

Type:	string
Default:	null
Valid Values:
Importance:	low

sasl.oauthbearer.jwks.endpoint.refresh.ms¶

The (optional) value in milliseconds for the broker to wait between refreshing its JWKS (JSON Web Key Set) cache that contains the keys to verify the signature of the JWT.

Type:	long
Default:	3600000 (1 hour)
Valid Values:
Importance:	low

sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms¶

The (optional) value in milliseconds for the maximum wait between attempts to retrieve the JWKS (JSON Web Key Set) from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.

Type:	long
Default:	10000 (10 seconds)
Valid Values:
Importance:	low

sasl.oauthbearer.jwks.endpoint.retry.backoff.ms¶

The (optional) value in milliseconds for the initial wait between JWKS (JSON Web Key Set) retrieval attempts from the external authentication provider. JWKS retrieval uses an exponential backoff algorithm with an initial wait based on the sasl.oauthbearer.jwks.endpoint.retry.backoff.ms setting and will double in wait length between attempts up to a maximum wait length specified by the sasl.oauthbearer.jwks.endpoint.retry.backoff.max.ms setting.

Type:	long
Default:	100
Valid Values:
Importance:	low

sasl.oauthbearer.scope.claim.name¶

The OAuth claim for the scope is often named “scope”, but this (optional) setting can provide a different name to use for the scope included in the JWT payload’s claims if the OAuth/OIDC provider uses a different name for that claim.

Type:	string
Default:	scope
Valid Values:
Importance:	low

sasl.oauthbearer.sub.claim.name¶

The OAuth claim for the subject is often named “sub”, but this (optional) setting can provide a different name to use for the subject included in the JWT payload’s claims if the OAuth/OIDC provider uses a different name for that claim.

Type:	string
Default:	sub
Valid Values:
Importance:	low

scheduled.rebalance.max.delay.ms¶

The maximum delay that is scheduled in order to wait for the return of one or more departed workers before rebalancing and reassigning their connectors and tasks to the group. During this period the connectors and tasks of the departed workers remain unassigned

Type:	int
Default:	300000 (5 minutes)
Valid Values:	[0,…,2147483647]
Importance:	low

security.providers¶

A list of configurable creator classes each returning a provider implementing security algorithms. These classes should implement the org.apache.kafka.common.security.auth.SecurityProviderCreator interface.

Type:	string
Default:	“”
Valid Values:
Importance:	low

socket.connection.setup.timeout.max.ms¶

The maximum amount of time the client will wait for the socket connection to be established. The connection setup timeout will increase exponentially for each consecutive connection failure up to this maximum. To avoid connection storms, a randomization factor of 0.2 will be applied to the timeout resulting in a random range between 20% below and 20% above the computed value.

Type:	long
Default:	30000 (30 seconds)
Valid Values:	[0,…]
Importance:	low

socket.connection.setup.timeout.ms¶

The amount of time the client will wait for the socket connection to be established. If the connection is not built before the timeout elapses, clients will close the socket channel. This value is the initial backoff value and will increase exponentially for each consecutive connection failure, up to the socket.connection.setup.timeout.max.ms value.

Type:	long
Default:	10000 (10 seconds)
Valid Values:	[0,…]
Importance:	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.

Type:	list
Default:	null
Valid Values:
Importance:	low

ssl.client.auth¶

Configures kafka broker to request client authentication. The following settings are common:

ssl.client.auth=required If set to required client authentication is required.
ssl.client.auth=requested This means client authentication is optional. unlike required, if this option is set client can choose not to provide authentication information about itself
ssl.client.auth=none This means client authentication is not needed.

Type:	string
Default:	none
Valid Values:	[required, requested, none]
Importance:	low

ssl.endpoint.identification.algorithm¶

The endpoint identification algorithm to validate server hostname using server certificate.

Type:	string
Default:	https
Valid Values:
Importance:	low

ssl.engine.factory.class¶

The class of type org.apache.kafka.common.security.auth.SslEngineFactory to provide SSLEngine objects. Default value is org.apache.kafka.common.security.ssl.DefaultSslEngineFactory. Alternatively, setting this to org.apache.kafka.common.security.ssl.CommonNameLoggingSslEngineFactory will log the common name of expired SSL certificates used by clients to authenticate at any of the brokers with log level INFO. Note that this will cause a tiny delay during establishment of new connections from mTLS clients to brokers due to the extra code for examining the certificate chain provided by the client. Note further that the implementation uses a custom truststore based on the standard Java truststore and thus might be considered a security risk due to not being as mature as the standard one.

Type:	class
Default:	null
Valid Values:
Importance:	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.

Type:	string
Default:	SunX509
Valid Values:
Importance:	low

ssl.secure.random.implementation¶

The SecureRandom PRNG implementation to use for SSL cryptography operations.

Type:	string
Default:	null
Valid Values:
Importance:	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.

Type:	string
Default:	PKIX
Valid Values:
Importance:	low

status.storage.partitions¶

The number of partitions used when creating the status storage topic

Type:	int
Default:	5
Valid Values:	Positive number, or -1 to use the broker’s default
Importance:	low

status.storage.replication.factor¶

Replication factor used when creating the status storage topic

Type:	short
Default:	3
Valid Values:	Positive number not larger than the number of brokers in the Kafka cluster, or -1 to use the broker’s default
Importance:	low

task.shutdown.graceful.timeout.ms¶

Amount of time to wait for tasks to shutdown gracefully. This is the total amount of time, not per task. All task have shutdown triggered, then they are waited on sequentially.

Type:	long
Default:	5000 (5 seconds)
Valid Values:
Importance:	low

topic.creation.enable¶

Whether to allow automatic creation of topics used by source connectors, when source connectors are configured with topic.creation. properties. Each task will use an admin client to create its topics and will not depend on the Kafka brokers to create topics automatically.

Type:	boolean
Default:	true
Valid Values:
Importance:	low

topic.tracking.allow.reset¶

If set to true, it allows user requests to reset the set of active topics per connector.

Type:	boolean
Default:	true
Valid Values:
Importance:	low

topic.tracking.enable¶

Enable tracking the set of active topics per connector during runtime.

Type:	boolean
Default:	true
Valid Values:
Importance:	low

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