zentol commented on a change in pull request #7260: [hotfix][docs] Fix typo and make improvement in Kafka Connectors doc URL: https://github.com/apache/flink/pull/7260#discussion_r243232094
########## File path: docs/dev/connectors/kafka.md ########## @@ -713,14 +713,14 @@ the consumers until `transaction1` is committed or aborted. This has two implica **Note**: `Semantic.EXACTLY_ONCE` mode uses a fixed size pool of KafkaProducers per each `FlinkKafkaProducer011` instance. One of each of those producers is used per one checkpoint. If the number of concurrent checkpoints exceeds the pool size, `FlinkKafkaProducer011` -will throw an exception and will fail the whole application. Please configure max pool size and max -number of concurrent checkpoints accordingly. +will throw an exception and will fail the whole application. Please configure max pool size(`FlinkKafkaProducer011.kafkaProducersPoolSize`) +and max number of concurrent checkpoints(`CheckpointConfig.maxConcurrentCheckpoints`) accordingly. **Note**: `Semantic.EXACTLY_ONCE` takes all possible measures to not leave any lingering transactions -that would block the consumers from reading from Kafka topic more then it is necessary. However in the +that would block the consumers from reading from Kafka topic more than it is necessary. However in the event of failure of Flink application before first checkpoint, after restarting such application there is no information in the system about previous pool sizes. Thus it is unsafe to scale down Flink -application before first checkpoint completes, by factor larger then `FlinkKafkaProducer011.SAFE_SCALE_DOWN_FACTOR`. +application(`getNumberOfParallelSubtasks()`) before first checkpoint completes, by factor larger than `FlinkKafkaProducer011.SAFE_SCALE_DOWN_FACTOR`. Review comment: I don't understand the value in adding `getNumberOfParallelSubtasks` here. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] With regards, Apache Git Services
