We're considering using GlobalKTables / KeyValueStores for locally caching topic content in services. The topics would be compacted such that only the latest key/value pair would exist for a given key.
One question that's come up is how to determine, when bootstrapping the app, when the cache has been populated with the latest content from the topic (so we start with a "warm" cache). ReadOnlyKeyValueStore has an approximateNumEntries() method that we could use to see how much we've got, but trying to figure out how much there is in the topic looks much more difficult -- the only way I can see via the APIs / code is to use an AdminClient to get the topic partitions and then the KafkaConsumer to get the end offsets for those. Does anyone have experience doing this kind of caching? How did you handle the bootstrapping issue? Any thoughts on easier or better ways to determine when the cache is warm? thx, Chris
