Re: Adding topics to KafkaStreams after ingestion has been started?

I suppose the topic won't be deleted, but this would be a rare enough occurrence that there won't be too many dormant topics hanging around. Alternatively perhaps I can store the undeleted topics somewhere, and whenever a new node starts, it could check this list and delete them. On Sat, Dec 3,

Re: Adding topics to KafkaStreams after ingestion has been started?

Not sure. Would need to think about it more. However, default commit interval in streams is 30 sec. You can configure is via StreamConfig COMMIT_INTERVAL_MS. So using the additional thread and waiting for 5 minutes sounds ok. Question is, what would happen if the JVM goes down before you delete

Re: Adding topics to KafkaStreams after ingestion has been started?

Is there a way to make sure the offsets got committed? Perhaps, after the last msg has been consumed, I can setup a task to run after a safe time (say 5 mins? ) in another thread which would delete the topic? What would be a safe time to use? On Sat, Dec 3, 2016 at 3:04 PM, Matthias J. Sax

Re: Adding topics to KafkaStreams after ingestion has been started?

I guess yes. You might only want to make sure the topic offsets got committed -- not sure if committing offsets of a deleted topic could cause issue (ie, crashing you Streams app) -Matthias On 12/2/16 11:04 PM, Ali Akhtar wrote: > Thank you very much. Last q - Is it safe to do this from within a

Re: Adding topics to KafkaStreams after ingestion has been started?

Thank you very much. Last q - Is it safe to do this from within a call back processing that topic , once it reaches the last message? (It keeps a count of how many messages processed vs how many remaining) On 3 Dec 2016 11:36 a.m., "Matthias J. Sax" wrote: > You can use

Re: Adding topics to KafkaStreams after ingestion has been started?

You can use TopicCommand to delete a topic within Java: > final TopicCommand.TopicCommandOptions commandOptions = new > TopicCommand.TopicCommandOptions(new String[]{ > "--zookeeper", "zookeperHost:2181", > "--delete", > "--topic", "TOPIC-TO-BE-DELETED"}); >

Re: Adding topics to KafkaStreams after ingestion has been started?

Is there a way to delete the processed topics via streams or the java driver? Or only thru the bash script? On 3 Dec 2016 5:27 a.m., "Matthias J. Sax" wrote: > If you keep old topics that are completely processed, there would be > increasing overhead, because Streams

Re: Adding topics to KafkaStreams after ingestion has been started?

If you keep old topics that are completely processed, there would be increasing overhead, because Streams would try to read from those topics as long as they exist. Thus, more fetch request will be sent to those more topics over time, while most fetch request will return without any new data (as

Re: Adding topics to KafkaStreams after ingestion has been started?

Hey Matthias, So I have a scenario where I need to batch a group of messages together. I'm considering creating a new topic for each batch that arrives, i.e batch_. Each batch_ topic will have a finite number of messages, and then it will remain empty. Essentially these will be throwaway

Re: Adding topics to KafkaStreams after ingestion has been started?

1) There will be once consumer per thread. The number of thread is defined by the number of instances you start and how many threads you configure for each instance via StreamConfig parameter NUM_STREAM_THREADS_CONFIG. Thus, you control this completely by yourself. Depending on the number to

Re: Adding topics to KafkaStreams after ingestion has been started?

That's pretty useful to know - thanks. 1) If I listened too foo-.*, and there were 5 foo topics created after kafka streaming was running: foo1, foo2, foo3, foo4, foo5, will this create 5 consumers / threads / instances, or will it be just 1 instance that receives the messages for all of those

Re: Adding topics to KafkaStreams after ingestion has been started?

Hi Ali, The only way KafkaStreams will process new topics after start is if the original stream was defined with a regular expression, i.e, kafka.stream(Pattern.compile("foo-.*"); If any new topics are added after start that match the pattern, then they will also be consumed. Thanks, Damian On

Adding topics to KafkaStreams after ingestion has been started?

Heya, Normally, you add your topics and their callbacks to a StreamBuilder, and then call KafkaStreams.start() to start ingesting those topics. Is it possible to add a new topic to the StreamBuilder, and start ingesting that as well, after KafkaStreams.start() has been called? Thanks.