Hi,
Thanks for your reply Kamal and Oleg. Thanks and Regards A.SathishKumar >Also keep in mind that unfortunately KafkaConsumer.poll(..) will deadlock >regardless of the >timeout if connection to the broker can not be established and won't react to >thread interrupts. >This essentially means that the only way to exit is to kill jvm. This is all >because Kafka >fetches topic metadata synchronously before timeout takes effect. >While it is my understanding that the reason for it is there is a background >thread attempting >to reconnect in the event of temporary broker outage, it doesn't help if you >accidentally >specified wrong broker url. Oleg > On Aug 2, 2016, at 10:27, Kamal C <kamaltar...@gmail.com> wrote: > > See the answers inline. > >> On Tue, Aug 2, 2016 at 12:23 AM, sat <sathish.al...@gmail.com> wrote: >> >> Hi, >> >> I am new to Kafka. We are planning to use Kafka messaging for our >> application. I was playing with Kafka 0.9.0.1 version and i have following >> queries. Sorry for asking basic questions. >> >> >> 1) I have instantiated Kafka Consumer and invoked >> consumer.poll(Long.MAX_VALUE). Although i have specified timeout as >> Long.MAX_VALUE, i observe my consumer to fetch records whenever the >> publisher publishes a message to a topic. This makes me wonder whether >> Kafka Consumer is push or pull mechanism. Please help us understand the >> logic of consumer.poll(timeout). > > Fetches the data from the topic, waiting up to the specified wait time *if > necessary *for a record to become available. > Kafka Consumer by design is pull mechanism. > > Take a look into Kafka Consumer java docs[1]. It's explained in detail. > > >> 2) What are the pros and cons of poll for long timeout vs short timeout. >> >> Short Timeout > > Pros: > - On shutdown, if no data available in the topic -- Shutdown will be quick > > Cons: > - Number of network trips will be high > > >> >> Thanks and Regards >> A.SathishKumar > > [1]: > https://kafka.apache.org/090/javadoc/index.html?org/apache/kafka/clients/consumer/KafkaConsumer.html > > -- Kamal On Mon, Aug 1, 2016 at 11:53 AM, sat <sathish.al...@gmail.com> wrote: > Hi, > > I am new to Kafka. We are planning to use Kafka messaging for our > application. I was playing with Kafka 0.9.0.1 version and i have following > queries. Sorry for asking basic questions. > > > 1) I have instantiated Kafka Consumer and invoked > consumer.poll(Long.MAX_VALUE). Although i have specified timeout as > Long.MAX_VALUE, i observe my consumer to fetch records whenever the > publisher publishes a message to a topic. This makes me wonder whether > Kafka Consumer is push or pull mechanism. Please help us understand the > logic of consumer.poll(timeout). > > 2) What are the pros and cons of poll for long timeout vs short timeout. > > > Thanks and Regards > A.SathishKumar > > -- A.SathishKumar 044-24735023
