GitHub user lhotari added a comment to the discussion: Whats the right sizing of producers & consumers on a partitioned topic with all subscription types ?
> Similarly, when we create a Pulsar Consumer , want to understand if it > subscribes to all partitions or not, w.r.t 4 subscription modes. When using Shared or Key_Shared, each consumer instance will subscribe to all partitions of a partitioned topic. The only other usable option is Failover consumer where one consumer will be active for a single partition at a time. There's a solution for balancing the consumers of individual partitions across the instances so that a single instance doesn't consume all partitions when there are multiple instances available. I found the documentation in the javadoc of [ConsumerBuilder.priorityLevel](https://pulsar.apache.org/api/client/3.2.x/org/apache/pulsar/client/api/ConsumerBuilder.html#priorityLevel(int)). ConsumerBuilder.priorityLevel applies also to Shared subscription type, but it has a different purpose, it's for assigning the actual priorities or weights. I guess it's rare to have a use case for exclusive consumers for multi-partitioned topics although it would work technically. The use case for an exclusive consumer is for active-passive configurations and usually there needs to be partition level control so that all partitions are handled on a single instance instead of splitting consumers across multiple instances. Perhaps there are good usecases also for exclusive multi-partitioned consumers. Someone else could elaborate on this. GitHub link: https://github.com/apache/pulsar/discussions/22437#discussioncomment-9017684 ---- This is an automatically sent email for [email protected]. To unsubscribe, please send an email to: [email protected]
