Why would GlobalKTable with in-memory key-value st

问题:

I am trying to figure out how GlobalKTable is working and noticed that my in memory key value store is not filled in case a restart. However the documentation sounds that it is filled in case a restart since the whole data is duplicated on clients.

When I debug my application see that there is a file on /tmp/kafka-streams/category-client-1/global/.checkpoint and it is including an offset about my topic. This might be maybe necessary for stores which are persisting their data and improve restarts however since there is an offset in this file, my application skips restoring its state.

How can I be sure that each restart or fresh start includes whole data of my topic?

回答1:

Because you are using in-memory store I assume that you are hitting this bug: https://issues.apache.org/jira/browse/KAFKA-6711

As a workaround, you can delete the local checkpoint file for the global store -- this will trigger the bootstrapping on restart. Or you switch back to default RocksDB store.