Hi Rajan, A few comments on the PIP as I couldn't understand it fully as some pieces of information is missing.
First, I would like to remind about the rules, that exists in the beginning of the PIP template: <!-- RULES * Never place a link to an external site like Google Doc. The proposal should be in this issue entirely. * Use a spelling and grammar checker tools if available for you (there are plenty of free ones) PROPOSAL HEALTH CHECK I can read the design document and understand the problem statement and what you plan to change *without* resorting to a couple of hours of code reading just to start having a high level understanding of the change. --> In this specific case 1. I would include explanation and detail the data structures fields of objects you mentioned, such as: MessageIdImpl and MessageIdData. 2. I would not put a PR as the design section, so I need to read code to understand what the exact solution details. You wrote: > Pulsar api provides MessageId > <https://github.com/apache/pulsar/blob/master/pulsar-client-api/src/main/java/org/apache/pulsar/client/api/MessageId.java> > interface > which is generally used by producer and consumer applications to manage > topic offset. I think it's used to allow consumers to acknowledge (can be per message) so offset if wrong terminology here. For producers, not sure exactly its usage. Maybe if they need to refer to this message later when reading by Reader interface. I would correct this section. However, right now Pulsar doesn't support correct deserialization of > multi-topic or partitioned-topic because of that 1acknowledge` API call > fails for those topics with below error You're saying that the acknowledgement API method signature receives MessageId, but do not receive TopicMessageId? I have a few questions on that: 1. The acknowledgement API is part of Pulsar binary protocol. Is your plan to alter that protocol so it will also include the topic field as part of the message ID? 2. I think your PIP needs to explain the following items which are missing as context: - There are two implementation for MessageId interface, one for topic and one for partitioned topic. - The problem is that the serialization/desrialization method is used mainly for translating the ID into the binary protocol, which only requires the ID (ledger ID, entry ID). - The reason for that is that once you created a consumer, it has a topic attached to it. Transferring the topic for the ack is redundant. All of this needs to be in the background. I have several ideas on solving that, which IMO should mainly be in the client level, but I must get answers to the questions above before I can continue. Last note You have basically placed a link to a pull request as the design solution (high-level/detailed design). The whole idea of the design is that you describe the solution without resorting to code. IMO you should amend the design, state the goal shortly, and have a high level design section which contains 1-2 short paragraphs describing exactly your solution. Thanks, Asaf On Tue, May 9, 2023 at 3:24 PM Yunze Xu <x...@apache.org> wrote: > I'm talking about whether to add a new separate API. I'm concerned > about whether existing applications would be affected, no matter if > the existing implementation has the limitation. If yes, we should > document it in the PIP so that users can know that. > > > it's a new optional field which would not break the compatibility > > And yes, I just confirmed it with simple demos in my local env. So I'm > +1 to this proposal. > > Thanks, > Yunze > > On Tue, May 9, 2023 at 3:05 PM Rajan Dhabalia <rdhaba...@apache.org> > wrote: > > > > Weill there are multiple things: it's a new optional field which would > not > > break the compatibility , also current messaegId serialization and > > deserialization anyway only impact multi-topic consumer which is already > > broken or has the limitation and, adding a new separate API for > partitioned > > topic is not only not acceptable but creates too much confusion for users > > to use separate ack APIs for non-partition and partition topics and that > > also breaks partitioned topic abstraction which we would like to avoid. > > > > Thanks, > > Rajan > > > > On Mon, May 8, 2023 at 11:27 PM Yunze Xu <x...@apache.org> wrote: > > > > > It seems that `TopicMessageIdImpl#toByteArray` now could serialize the > > > optional topic field to the bytes. I didn't test it now but I have a > > > concern about whether it would bring a breaking change. > > > > > > Assuming there are two applications (let's say A and B) based on an > > > older Pulsar client, A writes serialized bytes into a file, B reads > > > bytes from the file and parses it to a MessageId. If A upgraded its > > > Pulsar client to the latest while B did not, what would happen? Could > > > B still get the correct MessageId or the bytes would not be able to > > > parsed? > > > > > > P.S. it's better to add the API changes and potential breaking changes > > > in the proposal. > > > > > > Thanks, > > > Yunze > > > > > > On Tue, May 9, 2023 at 1:59 PM Rajan Dhabalia <rdhaba...@apache.org> > > > wrote: > > > > > > > > Hi, > > > > > > > > Pulsar api provides MessageId interface which is generally used by > > > producer > > > > and consumer applications to manage topic offset. Sometimes, these > > > > applications would like to serialize and deserialize messageIds, > > > > specifically consumer app which would like to persist messageId and > ack > > > > with those messageIds by deserializing them. However, right now > Pulsar > > > > doesn't support correct deserialization of multi-topic or > > > partitioned-topic > > > > because of that 1acknowledge` API call fails for those topics with > below > > > > error: > > > > "Only TopicMessageId is allowed to acknowledge for a multi-topics > > > consumer" > > > > > > > > MessageIdImpl stores id metadata into MessageIdData which doesn't > contain > > > > context about topic name to find out which topic belongs to this > > > MessageID. > > > > Therefore, we need to add topic-name into MessageIdData and allow > > > > multi-topic/partitioned topics to deserialize messages correctly so, > > > > consumer app can perform as expected. > > > > > > > > Please visit PIP for any suggestions: > > > > https://github.com/apache/pulsar/issues/20221 > > > > > > > > This PIP is created with PR: > https://github.com/apache/pulsar/pull/19944 > > > > > > > > Thanks, > > > > Rajan > > > >
