Hi Nicolae In KStream-KStream, KStream-KTable, and KTable-KTable joins, both sides of the join need to have the same number of partitions. Kafka Streams will check for this, and if the number of partitions isn’t the same, Kafka Streams will throw a TopologyException.
Foreign key joins don’t require the same number of partitions between the two tables, since you provide a foreignKeyExtractor function that extracts the key for the join from the “calling” or left side table of the join. HTH, Bill FYI I've answered the question in the forum as well. On Thu, Feb 25, 2021 at 8:15 AM Dumitru Nicolae Marasoiu < nicolae.maras...@gmail.com> wrote: > Hi guys, in case of KTable with KTable joins, is co-location a requirement? > Do the 2 topics need to have the same number of partitions? > https://forum.confluent.io/t/ktable-ktable-joins-is-colocation-needed/1034 > Thank you, > Nicolae >