On Wed, Jul 13, 2022 at 1:55 AM Asaf Mesika <asaf.mes...@gmail.com> wrote:
> Few questions
>
> "CompletableFuture<Position> asyncMigrate();"
> Does this method only change the status of the managed ledger?
>
No, as it's mentioned in PIP: this API will terminate the topic so, it will
not allow any new write and producers on that topic, and then it flags the
topic as migrated and finally it sends migrated-topic response to
producers/caught-up consumers(with 0 backlog) for further redirection.
>
> "message ManagedLedgerInfo {
>
> // Flag to check if topic is terminated and migrated to different
> cluster
> optional bool migrated = 4;
>
> }"
>
> This flag then is only changed to true when it has finished migration: i.e.
> no new messages were written, all existing consumers finished reading all
> messages and disconnected and the topic can now be deleted?
>
This flag is to persist the state of managed-ledger that it's considered
for migration so, if a broker crashes then it knows about the
managed-ledger state.
> "Broker sends topic migration message to client so, producer/consumer at
> client side can handle redirection accordingly"
>
> For producers, the message will be sent the moment the status of the topic
> has changed, so all messages from there on will be written to the new
> cluster?
>
Yes.
> For consumers, the message will be sent when there are no more messages to
> read?
>
Yes.
>
>
>
> On Tue, Jul 12, 2022 at 8:23 PM Rajan Dhabalia <rdhaba...@apache.org>
> wrote:
>
> > Hi,
> >
> > We have created PIP-184 which helps users to perform cluster migration
> with
> > Apache Pulsar. Cluster migration or Blue-Green cluster deployment is one
> of
> > the proven solutions to migrate live traffic from one cluster to another.
> > One of the examples is applications running on Kubernetes sometimes
> require
> > a Kubernetes cluster upgrade which can cause downtime for the entire
> > application during a Kubernetes cluster upgrade. Blue-green deployment is
> > an application release model that gradually transfers user traffic from a
> > previous version of an app or microservice to a nearly identical new
> > release—both of which are running in production.
> >
> > The old version can be called the blue environment while the new version
> > can be known as the green environment. Once production traffic is fully
> > transferred from blue to green, blue can standby in case of rollback or
> be
> > pulled from production and updated to become the template upon which the
> > next update is made. We need such capability in Apache pulsar to migrate
> > live traffic from the blue cluster to the green cluster so, eventually,
> the
> > entire traffic moves from the blue cluster to the green cluster without
> > causing downtime for the topics.
> >
> > PIP: https://github.com/apache/pulsar/issues/16551
> >
> > Thanks,
> > Rajan
> >
>
