Hi All We have a transformer implementation in our Kafka Streams application that raises this exception, sometimes, when starting.
"java.lang.IllegalStateException: This should not happen as timestamp() should only be called while a record is processed" This happens when 'put' is called on a state store within the `transform` method of a custom `Transformer`. The full trace can be seen here, apologies for the JSON formatting: https://pastebin.com/QYKE7bSH * We did not see this when the input and output topic of the topology had only a single partition. * We do not see this when the streams thread is handling only a single partition of data. (ie 4 partitions, 4 consumers in the consumer group) * We see this when deploying the consumer group and the first consumers to connect are handling multiple partitions (assumed). Once all have started and each consumer is processing a single partition each, the issue appears to go away. We are using Kafka Streams Client: 0.10.2.1 Any suggestions would be welcome as for now I am assuming a programming error. I can confirm that within our code, we never call `timestamp()` on the context. Thanks Adrian
