Apache Kafka

Convoy supports ingesting events from Kafka topics. This is currently only supported in outgoing projects.

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Connecting to your Kafka topic

To connect your Kafka topic, you need to supply:

• The kafka cluster hostname and port (e.g., localhost:9092)
• The topic name (e.g., audit-log-events)
• The number of workers — the number of partitions for the topic should match the number of workers.
• The consumer group id —it is recommended that you set one— which by default this is set to an empty string.
• Supply authentication configured on the cluster

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Authentication

• Auth types: PLAIN and SCRAM
• Hash types: SHA512 and SHA256
• TLS: Enabled and Disabled

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Ingestion Options

There are two ways to ingest events into Convoy from your Kafka topic:

• Format the payload using the structure below as a guide and write it to your topic.

  reference payload

   {
      "event_type": "string, required",
      "data": "object, required",
      "custom_headers": { // optional
          "x-convoy-message-type": "single",
          "sample-header": "sample-value"
      },
      "idempotency_key": "string, optional",
      "owner_id": "string, optional", // if included, the event is sent to all endpoints with the owner-id
      "endpoint_id": "string, optional" // if included, the event is sent to a single endpoint
   }
  

  If x-convoy-message-type set to broadcast, the event will be sent to all endpoints in the project, ignoring both the endpoint_id and owner_id values.

  For a full list of reference payloads, see our guide on ingesting events

• Send your arbitrarily formatted event payloads to your topic and use Convoy’s transform functions to mutate them at the point of ingestion.

  transform function

  function transform(payload) {
      return {
          "endpoint_id": "",
          "owner_id": "",
          "event_type": "sample",
          "data": payload, // payload contains arbitrary message data read from your topic
          "custom_headers": {
              "sample-header": "sample-value"
          },
          "idempotency_key": ""
      }
  }
  

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Things to note

• Messages are read of the topic one-by-one by each worker reading off a partition.
• Acknowledgements are done per message.
• Ingestion is rate-limited (50 per second), and this can be configured by setting the CONVOY_INGEST_RATE environment variable.