Re: Restructure data in GlobakKTable

2019-08-20 Thread Matthias J. Sax
Sounds reasonable. Note that a `GlobalKTable` is designed to read data from an topic only without further processing. That's why you don't get any "output stream". For fault-tolerance, the input topic is used, and hence, there is also no "changelog topic". I agree that option (1) is not ideal wit

Questions for platform to choose

2019-08-20 Thread Eliza
Hello, We have all of spark, flink, storm, kafka installed. For realtime streaming calculation, which one is the best above? Like other big players, the logs in our stack are huge. Thanks.

Re: Kafka Streams incorrect aggregation results when re-balancing occurs

2019-08-20 Thread Alex Brekken
Thanks guys. I knew that re-processing messages was a possibility with at_least_once processing, but I guess I hadn't considered the potential impact on the state stores as far as aggregations are concerned. So with exactly_once, it must roll-back commit(s) to the state store in a failure scenari

Re: Kafka Streams incorrect aggregation results when re-balancing occurs

2019-08-20 Thread Bruno Cadonna
Hi Alex, what you describe about failing before offsets are committed is one reason why records are processed multiple times under the at-least-once processing guarantee. That is reality of life as you stated. Kafka Streams in exactly-once mode guarantees that this duplicate state updates do not h

Re: list of pattern processed topic list

2019-08-20 Thread Matthias J. Sax
#listTopic() is not related to your subscription/assignment as indicated by its JavaDocs: > Get metadata about partitions for all topics that the user is authorized to > view. This method will issue a > remote call to the server. -Matthias On 8/19/19 7:02 AM, Kamal Chandraprakash wrote: > You

Consumer poll / fetch timeout

2019-08-20 Thread Shreesha Hebbar
Hi all, Noticing some of the consumer fetch timing out (2-10 sec), even though there is a steady rate of ingestion that is being seen on the topic. Any leads on how to triage such an issue?

RE: Kafka Streams incorrect aggregation results when re-balancing occurs

2019-08-20 Thread Tim Ward
I asked an essentially similar question a week or two ago. The answer was "this is expected behaviour unless you switch on exactly-once processing". (In my case it was solved by changing the topology, which I had to do for other, unconnected, reasons (the requirements for the application changed