7 ms·

Why is that?

• dominotw 6y ago
  millions of topics, no zookeeper ect. Kafka is addressing these shortcomings on the roadmap.
  • nitwit005 6y ago
    The Pulsar documentation says it requires Zookeeper: https://pulsar.apache.org/docs/en/administration-zk-bk/ https://pulsar.apache.org/docs/en/administration-zk-bk/
    • dominotw 6y ago
      oh sorry i meant storing topic info in zookeper that limits kafka to a certain number of topics.
      • EdwardDiego 6y ago
        Nope, it also stores topic metadata in ZK - it's not exactly going to store that in the (near) stateless brokers, or in Bookkeeper - and BK also relies on ZK, but it's common to reuse the ZK quorum between the brokers and the bookies. It also needs an additional ZK for cluster replication.
  • oweiler 6y ago
    For a lot a projects this is hardly a problem. On the other hand Kafka is more mature and has a huge ecosystem (Kafka Connect, Kafka Streams, KSQL, ...).
    • math 6y ago
      Kafka also has less moving parts even today before zookeeper removal is complete (2 vs pulsar 3).
      • biggestlou 6y ago
        But one of those moving parts of Pulsar, BookKeeper, means that you're no longer storing data on message brokers. Worth the extra puzzle piece for a lot of use cases.
    • biggestlou 6y ago
      Pulsar is less mature but does provide functional equivalents to all of the above. Pulsar IO (Kafka Connect), Pulsar SQL (KSQL), Pulsar Functions (Kafka Streams).
      • EdwardDiego 6y ago
        Nah, Pulsar functions is nowhere near Kafka Streams - it's more like AWS lambda. Example off the top of my head, is that you can't, in Pulsar Functions write the equivalent of "aggregate this stream across a 10 minute window and emit the results on window close". But that's fine, it doesn't need to be like Kafka Streams, you can use Flink or Spark or Storm etc. to fill the same niche. In fact one of the founders of StreamNative (Pulsar's equivalent of Confluent) is a core committer on Flink.
    • skyde 6y ago
      Kafka is not more mature just more hyped. I just wish Aphyr jepsen test would also cover more scenario like - what happen to your data if x+1 server permanently fail in the cluster with a replication factor of X. - what happen if a single partition data size or request rate become 90% of the cluster capacity - what happen in multi-tenancy scenario to other user throughput and latency when one user try to use all the capacity of the cluster - ...
      • EdwardDiego 6y ago
        It's way more mature. I just spent a week evaluating Pulsar vs Kafka for a client and the fact Kafka has been open sourced for 10 years vs. Pulsar's 1.5 really shows in documentation, community support etc. > what happen to your data if x+1 server permanently fail in the cluster with a replication factor of X. It depends on how many in sync replica sets existed entirely within those X+1 servers. Their partitions will go offline, and other ISRs will have underreplicated partitions, and the alerting you've set up as a good engineer will have told you this was happening. > what happen in multi-tenancy scenario to other user throughput and latency when one user try to use all the capacity of the cluster Nothing because you're using ACL and have configured quotas appropriately. Bad things otherwise. PS, also been running Kafka since 0.8.
        • skyde 6y ago
          if replication factor is 3 and 3 server go down in the span of 1 or 2 hours no alert will save you
          • EdwardDiego 6y ago
            Yes, but this is true of any system offering N - 1 safety, e.g., HDFS, Vertica, Pulsar. It's not specific to Kafka. And you can switch to your warm replicated cluster in this scenario, if you have one, Mirror Maker 2 supports replicated offsets so consumers can switch without losing state. But what you're describing is going to shaft any replicated system.
            • 6y ago
• wpietri 6y ago
  If anybody has seen a good detailed comparison, I'd love to read one. The first dozen hits were pretty weak.