Thank you very much, the example is really helpful. My last question is : Why is it necessay to seek the consumer offsets into the onPartitionsAssigned method ?
https://github.com/omkreddy/kafka-examples/blob/master/consumer/src/main/java/kafka/examples/consumer/advanced/AdvancedConsumer.java#L120 2016-04-15 15:06 GMT+02:00 Kamal C <kamaltar...@gmail.com>: > Hi Florian, > > This may be helpful > > https://github.com/omkreddy/kafka-examples/blob/master/consumer/src/main/java/kafka/examples/consumer/advanced/AdvancedConsumer.java > > --Kamal > > On Fri, Apr 15, 2016 at 2:57 AM, Jason Gustafson <ja...@confluent.io> > wrote: > > > Hi Florian, > > > > It's actually OK if processing takes longer than the heartbeat interval, > > but it does need to finish before the session timeout expires or the > > consumer will be kicked out of the group (which typically is revealed by > > commit failures). If the problem is just that the consumer is handling > too > > many messages at once, then Kafka 0.10 has an option to tune the number > of > > messages returned from poll() (max.poll.records), which may be helpful. > We > > also have a pause/resume API which allows you to call poll() without > > consuming any data. That's the best option at the moment for 0.9 > consumers. > > > > For what it's worth, we've considered several times adding a heartbeat() > > API, but the challenge is figuring out how to handle rebalancing. > > Underneath the covers, we use heartbeats to find out when the group is > > rebalancing, so a heartbeat() option would probably have to return a flag > > indicating whether a rebalance was needed. If the group has begun > > rebalancing, then you would need to call poll() before the expiration of > > the session timeout so that the consumer can join the rebalance. > > Alternatively, we could let heartbeat() complete the rebalance itself, > but > > then you'd have to be prepared to abort processing from the rebalance > > callback. That's not really different from calling poll() after pausing > > partitions though. The main problem in any case is that once a rebalance > > begins, you have the duration of the session timeout to stop processing > and > > join the rebalance. We're seeing this problem pop up pretty much > everywhere > > that the consumer is used, so we're trying to think of some better > options > > to handle it. > > > > Thanks, > > Jason > > > > > > On Thu, Apr 14, 2016 at 12:32 PM, Florian Hussonnois < > > fhussonn...@gmail.com> > > wrote: > > > > > Hi everyone, > > > > > > I have a use case where a message can take longer than ' > > > heartbeat.interval.ms' to be processed by my application. As I > > understand > > > the heartbeats of consumer are done while the poll method is invoked. > > > > > > I would like to instantiate a worker thread to process the messages > but I > > > need to wait for the messages completion before polling again. > > > > > > Is there a way to force the consumer to make an heartbeat without > polling > > > new messages ? > > > > > > Thanks, > > > > > > -- > > > Florian HUSSONNOIS > > > > > > -- Florian HUSSONNOIS
