Appearance

MigrationDocs 1.3.x

Kafka Adapter Validation ​

Applies to @connectum/events-kafka 1.3.0.

Does this apply to you? ​

You need to act if KafkaAdapter() receives any of these, because it now throws when it is called instead of failing later:

  • no options object (KafkaAdapter(undefined) used to throw Cannot use 'in' operator from inside the adapter);
  • brokers that is not an array of non-empty strings, or is empty (brokers: [] used to fail at connect(); brokers: 'localhost:9092' was accepted);
  • a clientId that is an empty string;
  • a consumerOptions.sessionTimeout that is not a finite number above 3000 ms (the client refused it at the first subscribe());
  • a retry.retries that is not a non-negative integer, or a retry.maxRetryTime, initialRetryTime, factor or multiplier that is negative or not finite;
  • a sasl.mechanism outside plain, scram-sha-256, scram-sha-512, oauthbearer and aws.

If none of these applies, nothing changes for you. Valid values behave as before.

Required changes ​

  • Pass brokers as an array: ['kafka-1:9093', 'kafka-2:9093']. A function that resolves the list is not part of the adapter's types and is no longer accepted.
  • Remove an empty clientId, or give it a name. Without it the adapter uses the service identifier of the event bus, or connectum.
  • Raise consumerOptions.sessionTimeout above 3000. Brokers also enforce their own minimum (group.min.session.timeout.ms, 6000 by default in Apache Kafka).
  • Use one of the five SASL mechanisms in the typed sasl option. A mechanism that only the client library implements goes in clientOptions.sasl.
typescript
// Before: accepted, failed at connect()
KafkaAdapter({ brokers: [] });

// After: throws RangeError "KafkaAdapter: brokers must contain at least one broker address"
KafkaAdapter({ brokers: ['kafka-1:9092'] });

Behavior that changed without an option ​

  • With consumerOptions.allowAutoTopicCreation: true, subscribe() waits up to ten seconds for the broker to create a missing topic. Without the option it rejects with an error that names the topic. See topics that do not exist yet.
  • Overlapping connect() calls share one attempt, and error messages for an unreachable localhost and for an invalid topic name now carry the reason and the topic. See connection errors.

Verify the upgrade ​

Create the adapter in a startup test: an invalid option throws at that call, before any connection is made.