This might not work because same PulsarClient can be used to create multiple topics and producer/consumer and migration state can be different per topic and even for produce/consumer (of same topic) so, changing service url will not work for blue-green migration redirection for all topics served by that PulsarClient. Sent from my iPhone
> On Jan 25, 2024, at 6:57 PM, Heesung Sohn <hees...@apache.org> wrote: > > Hi dev, > > I would like to discuss this change with the community. > > Motivation: > By this BlueGreenClusterMigration PIP-188( > https://github.com/apache/pulsar/pull/17962), `redirectedClusterURI` member > var has been introduced in the pulsar client to hold the new cluster's > endpoint. Accordingly, pulsar client also added a state of a map of > LookupService to lookup the migrated clusters. If redirectedClusterURI is > not null, then clients look up the mapped, > redirectedClusterURI->LookupService, when clients connect to migrated > brokers. > > Proposal: > In fact, this logic can be simplified by directly updating the > existing lookup service's service url. Then, we don't need to track the new > lookup services in a separate map and remove `redirectedClusterURI`, > either. > > Hers is the sample code for this proposal: > https://github.com/heesung-sn/pulsar/pull/59/ > > Pros: > - The removal of redirectedClusterURI and the lookup service map can > simplify the client code > - It works better with other logics: Bundle Transfer and > AutoClusterFailover, as these features currently only use the original > lookup service. > > Cons: > - To consume backlog from the blue (old) cluster, new clients need to be > created with the old service url(pointing to the old cluster) because the > existing clients' lookup service will be already updated, pointing to the > new cluster. > > However, I think this(requiring a new client with old service url, old > cluster) makes sense because all of the existing pub/sub will anyway be > reconnected to the new clusters as per the broker's close commands. So, to > consume the backlog from the old cluster, new client applications need to > start with the old service url anyway. > > Example: > https://github.com/heesung-sn/pulsar/pull/59/files#diff-3c745333eaeae9e8a87e92495fbf97b7c952c034b8c18ca92156f07cd5b1f5afR308-R312 > > Thanks, > Heesung
