Thank you Rajan for explaining the crucial importance of client compatibility in a very clear way. Ensuring client compatibility is a "must" requirement.
We happened to have some discussions about this topic at ApacheCon, and how to ensure protocol compatibility in the cases where there would be a need to move forward with the protocol to add an important new feature. The use case for this is Pulsar load balancing without any interruptions for producers and clients, thus a transparent handover of topics across brokers. This would require Pulsar protocol changes, and that is a problem for existing clients. We accepted this challenge and brainstormed. In this discussion, Chris Bartholomew introduced us to a genius idea: to have a proxy layer which supports the older protocol version and which adapts to any newer protocol version that contains some advanced features such as transparent handover for load balancing a topic across brokers. There could also be additional features, such as minimizing TCP/IP reconnects during topic unloads and making those completely transparent for clients that don't currently tolerate that properly (some existing Golang client versions). This additional feature could be controlled in some way. We evolved this idea together further and came up with the idea that this proxy layer could be a built-in part of the brokers themselves. This story that happened at a ApacheCon lunch is a good example how we are much greater together as a community than working independently in isolation. I'm really excited to have more Pulsar enthusiasts join this journey of co-creation. It is super fun! BR, -Lari On 2022/10/07 22:37:19 Rajan Dhabalia wrote: > Hi, > > Can we get the list of changes at one place which we are planning to get as > part of 3.0. One thing I would like to see as a part of a major release, it > CAN NOT impact existing usecases and users in any way which can force them > to upgrade the client library. Applications using < 3.0 version should > continue getting all the client and server side enhancements and bug fixes. > Failing to provide bug-fixes and features to client < 3.0 means we are > forcing them to upgrade client version by putting efforts to handle all > incompatibility. and that's something we should definitely prevent because > Apache Pulsar is used by many large scale business usecases and we should > accommodate and motivate them to continue using Apache Pulsar. > I understand as a Pulsar community we should always try to progress and > build better but not at the cost of losing or reducing the Apache Pulsar > community. > > Thanks, > Rajan > > > On Fri, Oct 7, 2022 at 12:41 PM Lari Hotari <lhot...@apache.org> wrote: > > > Thank you, Matteo. I agree that features should be delivered continuously > > when that is possible. In this case, that might not apply. > > > > I also agree that calling this Pulsar 3.0 isn't necessarily aligned with > > PIP-175 since an LTS release is when the major version is bumped. I'm fine > > in calling this "Pulsar Next Gen" or something that calls out that this is > > planning for making a major leap in Pulsar. > > > > There are several unresolved issues with PIP-45 and the Pulsar Load > > balancer. The previously referred email threads contain a lot of context to > > this. Resolving the issues efficiently will most likely result in breaking > > changes, which will be the reason why it deserves a major version upgrade. > > > > We have discussed it before that it's crucial to have a path to migrate > > users when there are breaking changes. This should be covered in any of the > > solutions that are introduced. Optimally, users of Pulsar would be able to > > upgrade seamlessly to Pulsar Next Gen / Pulsar 3.0, but rolling back might > > not be directly supported. > > > > I am welcoming everyone to join this planning for the Apache Pulsar Next > > Gen architecture. Please check the first email in this thread for details > > of context, and start participating and contributing today. The best way to > > contribute is to participate in the email threads, since they contain > > details with better context. > > > > -Lari > > > > On 2022/10/07 18:03:00 Matteo Merli wrote: > > > Given the past experiences and the discussions that already happened > > > around "PIP-175: Extend time based release process", the idea is to > > > detach the 3.0 from "big-features" items or "incompatible changes". > > > > > > The changes are going to get included as they are ready, within > > > feature releases, and in a fully compatible way. We don't need to > > > group them together and create unnecessary risk for the release > > > schedule and the users. > > > > > > > > > -- > > > Matteo Merli > > > <matteo.me...@gmail.com> > > > > > > On Fri, Oct 7, 2022 at 10:47 AM Lari Hotari <lhot...@apache.org> wrote: > > > > > > > > Hi all, > > > > > > > > Greeting from ApacheCon North America 2022 from New Orleans! > > > > We had a great conference with a dedicated Pulsar track. Thanks to all > > presenters and everyone who attended. The talks weren't recorded, but the > > slides will be later on posted on the conference website [1]. > > > > > > > > At ApacheCon there were several presentations about "the Apache way" > > and what that means in practice. Based on that, we all know that no person > > is nominated as the CTO of Apache Pulsar who decides on Pulsar 3.0 and when > > that happens. It's us, the community, that serve that role together. We > > come together as individuals with the Apache hat on. Everyone is equal in > > the community, regardless of whether they are contributors, committers or > > PMC members. > > > > We welcome everyone to participate. The small detail about voting > > shouldn't stop anyone from participating in any aspects of the planning for > > the roadmap. > > > > > > > > I'll like to get the discussions going for Pulsar 3.0. We don't need a > > separate decision to start planning that. Please correct me if I'm wrong or > > if you have a different opinion. > > > > > > > > There are a few previous discussion threads that are related to Pulsar > > 3.0 planning. > > > > If you are interested in getting involved with Apache Pulsar 3.0 > > planning, I think that it makes sense for you to read these threads > > carefully and reply to them. Please also suggest what you think makes sense. > > > > > > > > PIP-45 related: > > https://lists.apache.org/thread/tvco1orf0hsyt59pjtfbwoq0vf6hfrcj > > > > Pulsar Load balancer / namespace bundle related: > > > > https://lists.apache.org/thread/roohoc9h2gthvmd7t81do4hfjs2gphpk > > > > renaming topics: > > > > https://lists.apache.org/thread/vrr75rrh4trqlp14objh3snlfvmzdrp2 > > > > backpressure: > > https://lists.apache.org/thread/v7xy57qfzbhopoqbm75s6ng8xlhbr2q6 > > > > > > > > Long list of Metadata inconsistency issues by Zac Bentley: > > > > https://github.com/apache/pulsar/issues/12555 > > > > That would be a good starting point to understanding the data > > inconsistency issues related to current PIP-45 design. Perhaps those could > > be addressed already before Pulsar 3.0? > > > > > > > > I'm looking forward to everyone's participation in the Apache Pulsar > > 3.0 planning discussions. > > > > > > > > Best Regards, > > > > > > > > -Lari > > > > > > > > 1 - https://www.apachecon.com/acna2022/schedule.html > > > > > >
