kafka sink

Streams `log` events to Apache Kafka via the Kafka protocol.

The kafka sink streams log events to Apache Kafka via the Kafka protocol.

Config File

vector.toml (simple)
vector.toml (advanced)
type = "kafka" # must be: "kafka"
inputs = ["my-source-id"]
bootstrap_servers = ["", ""]
encoding = "json" # enum: "json" or "text"
key_field = "user_id"
topic = "topic-1234"
# For a complete list of options see the "advanced" tab above.

How It Works

Delivery Guarantee

This component offers an at least once delivery guarantee if your pipeline is configured to achieve this.


The kafka sink encodes events before writing them downstream. This is controlled via the encoding option which accepts the following options:




The payload will be encoded as a single JSON payload.


The payload will be encoded as new line delimited text, each line representing the value of the "message" key.

Dynamic encoding

By default, the encoding chosen is dynamic based on the explicit/implcit nature of the event's structure. For example, if this event is parsed (explicit structuring), Vector will use json to encode the structured data. If the event was not explicitly structured, the text encoding will be used.

To further explain why Vector adopts this default, take the simple example of accepting data over the tcp source and then connecting it directly to the kafka sink. It is less surprising that the outgoing data reflects the incoming data exactly since it was not explicitly structured.

Environment Variables

Environment variables are supported through all of Vector's configuration. Simply add ${MY_ENV_VAR} in your Vector configuration file and the variable will be replaced before being evaluated.

You can learn more in the Environment Variables section.

Health Checks

Health checks ensure that the downstream service is accessible and ready to accept data. This check is performed upon sink initialization.

If the health check fails an error will be logged and Vector will proceed to start. If you'd like to exit immediately upon health check failure, you can pass the --require-healthy flag:

vector --config /etc/vector/vector.toml --require-healthy

And finally, if you'd like to disable health checks entirely for this sink you can set the healthcheck option to false.


The kafka sink streams data on a real-time event-by-event basis. It does not batch data.


The best place to start with troubleshooting is to check the Vector logs. This is typically located at /var/log/vector.log, then proceed to follow the Troubleshooting Guide.

If the Troubleshooting Guide does not resolve your issue, please:

  1. Check for any open kafka_sink issues.

  2. If encountered a bug, please file a bug report.

  3. If encountered a missing feature, please file a feature request.

  4. If you need help, join our chat/forum community. You can post a question and search previous questions.