Thanks Bill. So poking around the code a bit, it looks like perhaps any kafka streams execution that produces a state store would execute this "restore state store" operation, even creating a new state store, is that correct? If so that indeed could be just what I need.
On Tue, Nov 13, 2018 at 6:38 PM Bill Bejeck <b...@confluent.io> wrote: > Hi Chris, > > I'm not sure I totally understand your requirements but the > StateRestoreListener ( > > https://kafka.apache.org/20/javadoc/org/apache/kafka/streams/processor/StateRestoreListener.html > ) > class provides callbacks when restoring state stores (including > GlobalStores) and may provide what you are looking for. > > Thanks, > Bill > > On Tue, Nov 13, 2018 at 8:49 PM Chris Toomey <ctoo...@gmail.com> wrote: > > > Definitely Ryanne -- that's what I meant by "topics would be compacted". > > > > But that doesn't obviate checking bootstrapping progress. > > > > On Tue, Nov 13, 2018 at 5:04 PM Ryanne Dolan <ryannedo...@gmail.com> > > wrote: > > > > > Chris, consider using log compaction. > > > > > > Ryanne > > > > > > On Tue, Nov 13, 2018, 3:17 PM Chris Toomey <ctoo...@gmail.com> wrote: > > > > > > > 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 > > > > > > > > > >
