> > But it seems that currently all Durable subscriptions on > non-persistent topics are NonDurable, and I wonder if that confuses > users. >
We can add validation to inform the user that a durable subscription on a non-persistent topic is invalid. Thanks, Baodi Shi 在 2023年2月8日 10:48:32 上，Zike Yang <z...@apache.org> 写道： > 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 > > >
