Good catch. Could you create a ticket? You can also submit a PR to fix it if you have time :)

On Tue, Mar 7, 2017 at 1:52 PM, Bowden, Chris <chris.bowden@hpe.com> wrote:

Potential bug when using startingOffsets = SpecificOffsets with Kafka topics containing uppercase characters?

KafkaSourceProvider#L80/86:

val startingOffsets =
caseInsensitiveParams.get(STARTING_OFFSETS_OPTION_KEY).map(_.trim.toLowerCase) match {
case Some("latest") => LatestOffsets
case Some("earliest") => EarliestOffsets
case Some(json) => SpecificOffsets(JsonUtils.partitionOffsets(json))
case None => LatestOffsets
}
Topics in JSON get lowered so underlying assignments in the consumer are incorrect, and the assertion in KafkaSource#L326 triggers:
private def fetchSpecificStartingOffsets(
partitionOffsets: Map[TopicPartition, Long]): Map[TopicPartition, Long] = {
val result = withRetriesWithoutInterrupt {
// Poll to get the latest assigned partitions
consumer.poll(0)
val partitions = consumer.assignment()
consumer.pause(partitions)
assert(partitions.asScala == partitionOffsets.keySet,
"If startingOffsets contains specific offsets, you must specify all TopicPartitions.\n" +
"Use -1 for latest, -2 for earliest, if you don't care.\n" +
s"Specified: ${partitionOffsets.keySet} Assigned: ${partitions.asScala}")