• A component of thekafka integration plugin
• Integration version: v11.3.2
• Released on: 2023-10-16
• Changelog

For other versions, see theoverview list.

To learn more about Logstash, see theLogstash Reference.

For questions about the plugin, open a topic in theDiscuss forums. For bugs or feature requests, open an issue inGithub. For the list of Elastic supported plugins, please consult theElastic Support Matrix.

Write events to a Kafka topic.

This plugin uses Kafka Client 3.4. For broker compatibility, see the officialKafka compatibility reference. If the linked compatibility wiki is not up-to-date, please contact Kafka support/community to confirm compatibility.

If you require features not yet available in this plugin (including client version upgrades), please file an issue with details about what you need.

This output supports connecting to Kafka over:

• SSL (requires plugin version 3.0.0 or later)
• Kerberos SASL (requires plugin version 5.1.0 or later)

By default security is disabled but can be turned on as needed.

The only required configuration is the topic_id.

The default codec is plain. Logstash will encode your events with not only the message field but also with a timestamp and hostname.

If you want the full content of your events to be sent as json, you should set the codec in the output configuration like this:

output {  kafka {    codec => json    topic_id => "mytopic"  }}

For more information seehttps://kafka.apache.org/34/documentation.html#theproducer

Kafka producer configuration:https://kafka.apache.org/34/documentation.html#producerconfigs

This plugin supports the following configuration options plus theCommon options described later.

Also seeCommon options for a list of options supported by all output plugins.

• Value can be any of:0,1,all
• Default value is"1"

The number of acknowledgments the producer requires the leader to have received before considering a request complete.

acks=0. The producer will not wait for any acknowledgment from the server.

acks=1. The leader will write the record to its local log, but will respond without waiting for full acknowledgement from all followers.

acks=all. The leader will wait for the full set of in-sync replicas before acknowledging the record.

• Value type isnumber
• Default value is16384.

The producer will attempt to batch records together into fewer requests whenever multiple records are being sent to the same partition. This helps performance on both the client and the server. This configuration controls the default batch size in bytes.

• Value type isstring
• Default value is"localhost:9092"

This is for bootstrapping and the producer will only use it for getting metadata (topics, partitions and replicas). The socket connections for sending the actual data will be established based on the broker information returned in the metadata. The format ishost1:port1,host2:port2, and the list can be a subset of brokers or a VIP pointing to a subset of brokers.

• Value type isnumber
• Default value is33554432 (32MB).

The total bytes of memory the producer can use to buffer records waiting to be sent to the server.

• Value type isstring
• Valid options areuse_all_dns_ips,resolve_canonical_bootstrap_servers_only,default
• Default value is"default"

Controls how DNS lookups are done. If set touse_all_dns_ips, Logstash tries all IP addresses returned for a hostname before failing the connection. If set toresolve_canonical_bootstrap_servers_only, each entry will be resolved and expanded into a list of canonical names.

• Value type isstring
• There is no default value for this setting.

The 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 with the request

• Value can be any of:none,gzip,snappy,lz4,zstd
• Default value is"none"

The compression type for all data generated by the producer. The default is none (meaning no compression). Valid values are none, gzip, snappy, lz4, or zstd.

• Value type isnumber
• Default value is540000 milliseconds (9 minutes).

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

• Value type ispath
• There is no default value for this setting.

The Java Authentication and Authorization Service (JAAS) API supplies user authentication and authorization services for Kafka. This setting provides the path to the JAAS file. Sample JAAS file for Kafka client:

KafkaClient {  com.sun.security.auth.module.Krb5LoginModule required  useTicketCache=true  renewTicket=true  serviceName="kafka";  };

Please note that specifyingjaas_path andkerberos_config in the config file will add these to the global JVM system properties. This means if you have multiple Kafka inputs, all of them would be sharing the samejaas_path andkerberos_config. If this is not desirable, you would have to run separate instances of Logstash on different JVM instances.

• Value type ispath
• There is no default value for this setting.

Optional path to kerberos config file. This is krb5.conf style as detailed inhttps://web.mit.edu/kerberos/krb5-1.12/doc/admin/conf_files/krb5_conf.html

• Value type isstring
• Default value is"org.apache.kafka.common.serialization.StringSerializer"

Serializer class for the key of the message

• Value type isnumber
• Default value is0

The producer groups together any records that arrive in between request transmissions into a single batched request. Normally this occurs only under load when records arrive faster than they can be sent out. However in some circumstances the client may want to reduce the number of requests even under moderate load. This setting accomplishes this by adding a small amount of artificial delay—that is, rather than immediately sending out a record the producer will wait for up to the given delay to allow other records to be sent so that the sends can be batched together.

• Value type isnumber
• Default value is1048576 (1MB).

The maximum size of a request

• Value type isstring
• There is no default value for this setting.

The key for the message.

• Value type isnumber
• Default value is60000 milliseconds (60 seconds).

The timeout setting for initial metadata request to fetch topic metadata.

• Value type isnumber
• Default value is300000 milliseconds (5 minutes).

The max time in milliseconds before a metadata refresh is forced.

• Value type isstring
• There is no default value for this setting.

The default behavior is to hash themessage_key of an event to get the partition. When no message key is present, the plugin picks a partition in a round-robin fashion.

Available options for choosing a partitioning strategy are as follows:

• default use the default partitioner as described above
• round_robin distributes writes to all partitions equally, regardless ofmessage_key
• uniform_sticky sticks to a partition for the duration of a batch than randomly picks a new one

• Value type isnumber
• Default value is32768 (32KB).

The size of the TCP receive buffer to use when reading data

• Value type isnumber
• Default value is50.

The amount of time to wait before attempting to reconnect to a given host when a connection fails.

• Value type isnumber
• Default value is40000 milliseconds (40 seconds).

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.

• Value type isnumber
• There is no default value for this setting.

The default retry behavior is to retry until successful. To prevent data loss, the use of this setting is discouraged.

If you choose to setretries, a value greater than zero will cause the client to only retry a fixed number of times. This will result in data loss if a transport fault exists for longer than your retry count (network outage, Kafka down, etc).

A value less than zero is a configuration error.

Starting with version 10.5.0, this plugin will only retry exceptions that are a subclass ofRetriableException andInterruptException. If producing a message throws any other exception, an error is logged and the message is dropped without retrying. This prevents the Logstash pipeline from hanging indefinitely.

In versions prior to 10.5.0, any exception is retried indefinitely unless theretries option is configured.

• Value type isnumber
• Default value is100 milliseconds.

The amount of time to wait before attempting to retry a failed produce request to a given topic partition.

• Value type isstring
• There is no default value for this setting.

JAAS configuration setting local to this plugin instance, as opposed to settings using config file configured usingjaas_path, which are shared across the JVM. This allows each plugin instance to have its own configuration.

If bothsasl_jaas_config andjaas_path configurations are set, the setting here takes precedence.

Example (setting for Azure Event Hub):

output {  kafka {    sasl_jaas_config => "org.apache.kafka.common.security.plain.PlainLoginModule required username='auser'  password='apassword';"  }}

• Value type isstring
• There is no default value for this setting.

The Kerberos principal name that Kafka broker runs as. This can be defined either in Kafka’s JAAS config or in Kafka’s config.

• Value type isstring
• Default value is"GSSAPI"

SASL mechanism used for client connections. This may be any mechanism for which a security provider is available. GSSAPI is the default mechanism.

• Value can be any of:PLAINTEXT,SSL,SASL_PLAINTEXT,SASL_SSL
• Default value is"PLAINTEXT"

Security protocol to use, which can be either of PLAINTEXT,SSL,SASL_PLAINTEXT,SASL_SSL

• Value type isnumber
• Default value is131072 (128KB).

The size of the TCP send buffer to use when sending data.

• Value type isstring
• Default value is"https"

The endpoint identification algorithm, defaults to"https". Set to empty string"" to disable

• Value type ispassword
• There is no default value for this setting.

The password of the private key in the key store file.

• Value type ispath
• There is no default value for this setting.

If client authentication is required, this setting stores the keystore path.

• Value type ispassword
• There is no default value for this setting.

If client authentication is required, this setting stores the keystore password

• Value type isstring
• There is no default value for this setting.

The keystore type.

• Value type ispath
• There is no default value for this setting.

The JKS truststore path to validate the Kafka broker’s certificate.

• Value type ispassword
• There is no default value for this setting.

The truststore password

• Value type isstring
• There is no default value for this setting.

The truststore type.

• This is a required setting.
• Value type isstring
• There is no default value for this setting.

The topic to produce messages to

• Value type isstring
• Default value is"org.apache.kafka.common.serialization.StringSerializer"

Serializer class for the value of the message

These configuration options are supported by all output plugins:

• Value type iscodec
• Default value is"plain"

The codec used for output data. Output codecs are a convenient method for encoding your data before it leaves the output without needing a separate filter in your Logstash pipeline.

• Value type isboolean
• Default value istrue

Disable or enable metric logging for this specific plugin instance. By default we record all the metrics we can, but you can disable metrics collection for a specific plugin.

• Value type isstring
• There is no default value for this setting.

Add a uniqueID to the plugin configuration. If no ID is specified, Logstash will generate one. It is strongly recommended to set this ID in your configuration. This is particularly useful when you have two or more plugins of the same type. For example, if you have 2 kafka outputs. Adding a named ID in this case will help in monitoring Logstash when using the monitoring APIs.

output {  kafka {    id => "my_plugin_id"  }}