I agree to remove all subscriptions when there're no consumers on the non-persistent topic. The configuration `subscriptionExpirationTimeMinutes ` should not take effect on the non-persistent topic.
But it seems that currently all Durable subscriptions on non-persistent topics are NonDurable, and I wonder if that confuses users. > But for `NonPersistentDispatcherMultipleConsumers`, `NonPersistentStickyKeyDispatcherMultipleConsumers`, I’m not sure that if it matters when we auto delete the subscriptions which has no consumers connected. It doesn't matter IMO. Thanks, Zike Yang Zike Yang On Tue, Feb 7, 2023 at 9:22 PM Jiuming Tao <jm...@streamnative.io.invalid> wrote: > > > I think we are talking about the durable subscription of the non-persistent > > topic, right? > > Yes, non-durable subscriptions created by Reader, if the reader disconnected, > the subscription will be deleted automatically. > > > For `NonPersistentDispatcher`, it has the following implementations: > 1. NonPersistentDispatcherMultipleConsumers > 2. NonPersistentDispatcherSingleActiveConsumer > 3. NonPersistentStickyKeyDispatcherMultipleConsumers > > For `NonPersistentDispatcherSingleActiveConsumer`, auto delete the > subscription when there isn’t consumer connected affect nothing. > > But for `NonPersistentDispatcherMultipleConsumers`, > `NonPersistentStickyKeyDispatcherMultipleConsumers`, I’m not sure that if it > matters when we auto delete the subscriptions which has no consumers > connected. > > If it doesn’t matter, I agree with you. > > Auto delete the durable subscriptions when there aren’t consumers connected > to the non-persistent topic. > > > Thanks, > Tao Jiuming > > > > 2023年2月7日 19:58，PengHui Li <peng...@apache.org <mailto:peng...@apache.org>> > > 写道： > > > > I think we are talking about the durable subscription of the non-persistent > > topic, right? For the Reader API (non-durable subscription), the > > subscription will be > > removed after the reader disconnects. If not, it should be BUG. > > > > IMO, we should remove the subscription automatically if all the consumers > > are disconnected for the non-persistent topic. The consumers can only get > > the new incoming messages after they connect to the non-persistent topic. > > It looks like even if we leave the subscription there; it will > > help nothing. > > The behavior should be the same as creating a new subscription with the > > same subscription name. > > > > For subscription management, users are not able to disable the subscription > > auto-creation of the non-persistent topic? We don't have any metadata > > persist > > in the metadata store. After the broker restarts, we will lose everything. > > > > So I think we don't need to introduce a new configuration. Instead, we > > should > > figure out if there is a strong reason to leave the durable subscription > > after > > all the consumers are disconnected. If there is no strong reason, I tend to > > fix > > incorrect behavior directly. > > > > Best, > > Penghui > > > > > > > > > > On Tue, Feb 7, 2023 at 4:14 PM Jiuming Tao <jm...@streamnative.io.invalid > > <mailto:jm...@streamnative.io.invalid>> > > wrote: > > > >> Hi, > >> > >> I’ve opened a new PIP to discuss: > >> > >> Currently, in Pulsar, we have a configuration named > >> `subscriptionExpirationTimeMinutes` to manage the subscription expiration > >> of `PersistentTopic` and `NonPersistentTopic`. > >> > >> When we set a value which is greater than 0 to > >> `subscriptionExpirationTimeMinutes`, it will affect both `PersistentTopic` > >> and `NonPersistentTopic`. Their inactive subscriptions will get expired and > >> will clean automatically. > >> > >> For `NonPersistentTopic`, its subscriptions can be clean because we don't > >> guarantee its data integrity. But for `PersistentTopic`, if we clean its > >> subscriptions automatically may lead to data loss. > >> > >> However, their subscription expiration is managed by the same > >> configuration(`subscriptionExpirationTimeMinutes`), we can't manage their > >> subscription expiration independently. > >> > >> So I want to introduce a new configuration named > >> `nonPersistentSubscriptionExpirationTimeMinutes` to manage > >> `NonPersistentTopic`'s subscription expiration. > >> > >> > >> Please feel free to leave your comments, the PIP link: > >> https://github.com/apache/pulsar/issues/19448 > >> <https://github.com/apache/pulsar/issues/19448> < > >> https://github.com/apache/pulsar/issues/19448 > >> <https://github.com/apache/pulsar/issues/19448>> > >> > >> > >> Thanks, > >> Tao Jiuming >
