apache-pulsar

问题 I know you can set topic subscription to be shared subscription to allow for multiple Consumers on the same topic. Can this also be done for multiple Producers? For some reason when I try to, I get a Producer with name '<topic_name>' is already connected to topic 回答1: Yes, you can have multiple producers on a topic. You just have to make sure each producer has a unique name. From the ProducerBuilder.producerName section of the Java client API docs: When specifying a name, it is up to the user

问题 What is the cost of creating multiple subscriptions on a topic? Does creating more subscriptions affect the broker, Bookkeeper or both? I'm assuming it only adds work load to the broker but the work increased by adding another subscription is minimal since it would only have to duplicate the messages? 回答1: In Pulsar, a topic (or a partition) is owned by a single Broker meaning that all reads and writes go through that broker. Brokers cache bookies entries in memory so that it can dispatch

问题 Is it possible to scale Axon Framework without Axon Server Enterprise ? I'm interested in creating a prototype CQRS app with Axon, but the final, deployable system has to be be free from licensing fees. If Axon Framework can't be scaled to half a dozen nodes using free software, then I should probably look elsewhere. If Axon Framework turn out not to be a good choice for the system, what would you recommend? Would building something around Apache Pulsar be a sensible alternative? 回答1: I think

问题 Is it possible to scale Axon Framework without Axon Server Enterprise ? I'm interested in creating a prototype CQRS app with Axon, but the final, deployable system has to be be free from licensing fees. If Axon Framework can't be scaled to half a dozen nodes using free software, then I should probably look elsewhere. If Axon Framework turn out not to be a good choice for the system, what would you recommend? Would building something around Apache Pulsar be a sensible alternative? 回答1: I think

问题 Is it possible to scale Axon Framework without Axon Server Enterprise ? I'm interested in creating a prototype CQRS app with Axon, but the final, deployable system has to be be free from licensing fees. If Axon Framework can't be scaled to half a dozen nodes using free software, then I should probably look elsewhere. If Axon Framework turn out not to be a good choice for the system, what would you recommend? Would building something around Apache Pulsar be a sensible alternative? 回答1: I think

问题 From the doc: https://pulsar.apache.org/docs/en/cookbooks-retention-expiry/#get-the-ttl-configuration-for-a-namespace, it is a little bit confusing about the difference between backlog quotas and TTL. As I understand so far, a message arrives broker, and broker will find out all subscriptions on that topic, and retrieve their backlog, and put the message to those backlog. If this message is acknowledged by one subscription, it will be removed from its backlog (backlog is per subscription). If