[Cloud Computing] Kafka

What is the paper trying to do?

The paper is trying to introduce a novel messaging system for log processing, called Kafka. Kafka is a combination of the benefits of traditional log aggregator and messaging systems. Kafka is useful in processing huge volumes of log data streams, such as a messaging system. It is able to achieve higher throughput than other messaging systems because it focuses on log processing applications. There is a also integration for distributed support and can scale out.

What do you think is the contribution of the paper?

I think the main contribution of Kafka is the decisions the developer made to implement Kafka. For example, to make the system efficient, Kafka has a very simple storage layout, where each partition of a topic corresponds to a logical log. Another interesting decision is by making the consumer keep track of how much each consumer has consumed, as opposed to traditional methods where it is done by the broker. This reduces a lot of complexity and overhead on the broker.

What are its major strengths?

  • distributed and scalable
  • offers high throughput
  • provides API similar to messaging system
  • allow applications to consume log events in real time
  • open source
  • Successfully used in product at LinkedIn for more than 6 months (at the time of the paper’s writing.
In the paper, the authors performed a producer test and their numbers showed that Kafka can public messages with magnitude higher than of ActiveMQ and, at least, 2 times higher than RabbitMQ. There are a few reasons why Kafka performed better. First, Kafka producer doesn’t wait for acknowledgements from the broker. It just sends the messages as fast as the broker can handle. Second, Kafka “has a more efficient storage format”.


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