Omnia, I agree with you that allowing users to specify the whole topic name
via configuration is likely to create problems. MM2 must distinguish
between internal topics from different clusters, and pushing that
complexity into configuration sounds really complicated.
I like the ReplicationPolicy approach.
Ryanne
On Mon, Jun 21, 2021, 2:04 PM Omnia Ibrahim <o.g.h.ibra...@gmail.com> wrote:
> Any thoughts on this KIP?
>
>
> On Thu, Jun 17, 2021 at 1:38 PM Omnia Ibrahim <o.g.h.ibra...@gmail.com>
> wrote:
>
> > Another reason why I think adding a configuration for each internal
> topic is not a good solution is how MM2 is naming these topics at the
> moment.
> > Right now MM2 sets the name of the offset-syncs topic to
> mm2-offset-syncs.<cluster-alias>.internal and for checkpoints is
> <cluster-alias>.checkpoints.internal so the name has a pattern to link it
> back to the herder of source -> target mirror link so having this in
> configuration will lead to
> > 1. having a method that determines the final name of internal topics for
> backward compatibility and have this method to be the default of the
> configuration values. The challenge here is that we need to load first the
> clusters alias to calculate the default value for offset-syncs.topic.name
> and checkpoints.topic.name.
> > 2. Consider use cases where MM2 is used to mirror between multiple
> clusters, for example:
> > source1 -> target.enabled = true
> > source2 -> target.enabled = true
> > For this use-case the current behaviour will create the following
> offset-syncs and checkpoints on each cluster:
> > source1 cluster
> > - mm2-offset-syncs.target.internal
> > source2 cluster
> > - mm2-offset-syncs.target.internal
> > target cluster
> > - source1.checkpoints.internal
> > - source2.checkpoints.internal
> > As MM2 design in the original KIP-382 is spliting internal topics bsed
> on mirroring links. Now if we let MM2 users set the full name of these
> topics as configuration, how will we detect if the user has a wrong
> configuration where they used the same name for checkpoints topic for both
> source1 and source2. How this will work if both source1 and source2
> clusters have consumer groups with same ids as checkpoints topic messages
> contains consumer group id? Should we warn the MM2 user that this topic has
> been used before for another source cluster? If not how will the MM2 user
> notice that?
> >
> >
> > On Mon, Jun 14, 2021 at 5:54 PM Omnia Ibrahim <o.g.h.ibra...@gmail.com>
> > wrote:
> >
> >> Hi folks, let me try to clarify some of your concerns and questions.
> >>
> >> Mickael: Have you considered making names changeable via configurations?
> >>>
> >>
> >> Gwen: may be missing something, but we are looking at 3 new configs (one
> >>> for each topic). And this rejected alternative is basically identical
> to
> >>> what Connect already does (you can choose names for internal topics
> using
> >>> configs).
> >>>
> >>> These are valid points. The reasons why we should prefer an interface
> >> (the current proposal is using the ReplicationPolicy interface which
> >> already exists in MM2) instead are
> >>
> >> 1. the number of configurations that MM2 has. Right now MM2 has its own
> >> set of configuration in addition to configuration for admin, consumer
> and
> >> producer clients and Connect API. And these configurations in some
> >> use-cases could be different based on the herder.
> >>
> >> Consider a use case where MM2 is used to mirror between a set of
> clusters
> >> running by different teams and have different naming policies. So if we
> are
> >> using 3 configurations for internal topics for a use case like below the
> >> configuration will be like this. If the number of policies grows, the
> >> amount of configuration can get unwieldy.
> >>
> >> clusters = newCenterCluster, teamACluster, teamBCluster, ...
> >>
> >> //newCenterCluster policy is <teamName>.<topicName>
> >> //teamACluster naming policy is <app>_<topicName> when move to
> newCenterCluster it will be teamA.<app>_<topicName>
> >> //teamBCluster naming policy is <domain>.<topicName> when move to
> newCenterCluster it will be teamB.<domain>_<topicName>
> >>
> >> //The goal is to move all topics from team-specific cluster to one new
> cluster
> >> // where the org can unify resource management and naming conventions
> >>
> >> replication.policy.class=MyCustomReplicationPolicy
> >>
> >> teamACluster.heartbeat.topic=mm2_heartbeat_topic // created on source
> cluster
> >>
> teamACluster->newCenterCluster.offsets-sync.topic=mm2_my_offset_sync_topic
> //created on source cluster at the moment
> >>
> teamACluster->newCenterCluster.checkpoints.topic=teamA.mm2_checkpoint_topic
> //created on target cluster which newCenterCluster
> >>
> >> teamBCluster.heartbeat.topic=mm2.heartbeat_topic // created on source
> cluster
> >>
> teamBCluster->newCenterCluster.offsets-sync.topic=mm2.my_offset_sync_topic
> //created on source cluster at the moment
> >>
> teamBCluster->newCenterCluster.checkpoints.topic=teamB.mm2_checkpoint_topic
> //created on target cluster which newCenterCluster
> >>
> >> teamACluster.config.storage.topic=...
> >> teamACluster.offset.storage.topic=...
> >> teamACluster.status.storage.topic=...
> >>
> >> teamBCluster.config.storage.topic=...
> >> teamBCluster.offset.storage.topic=...
> >> teamBCluster.status.storage.topic=...
> >>
> >>
> >> teamACluster→newCenterCluster.enabled=true
> >> teamACluster→newCenterCluster.enabled=true
> >>
> >> 2. The other reason is what Mickael mentioned regards a future KIP to
> >> move offset-syncs on the target cluster.
> >>
> >>> Mickael: I'm about to open a KIP to specify where the offset-syncs
> topic
> >>> is created by MM2. In restricted environments, we'd prefer MM2 to only
> have
> >>> read access to the source cluster and have the offset-syncs on the
> target
> >>> cluster. I think allowing to specify the cluster where to create that
> topic
> >>> would be a natural extension of the interface you propose here.
> >>>
> >>
> >> In this case, where you want to achieve “read-only” on the source
> cluster
> >> then using ReplicationPolicy to name the offset-syncs topic makes more
> >> sense as ReplicationPolicy holds the implementation of how topics will
> be
> >> named on the target cluster where MM2 will have “write” access.
> >> For example, the user can provide their own naming convention for the
> >> target cluster as part of replication.policy.class =
> >> MyCustomReplicationPolicy where it formate the name of the replicated
> >> topic to be <something>.<topic>.<something>.Now if we have also an extra
> >> config for internal topics that will also be created at target with the
> >> similar naming convention <something>.<internal_topic>.<something> this
> >> means the user will need to add
> >> offset-sync.topic=<something>.<offset_topic_name>.<something> this feels
> >> like a duplication for me as we could achieve it by re-using the logic
> from
> >> ReplicationPolicy
> >>
> >> So using the replication interface we can define
> >> MyCustomReplicationPolicy like this following
> >>
> >> public class *MyCustomReplicationPolicy* implements ReplicationPolicy {
> >> @Override
> >> //How to rename remote topics
> >> public String *formatRemoteTopic*(String sourceClusterAlias, String
> topic) {
> >> return nameTopicOnTarger(sourceClusterAlias, topic, "mirrored");
> >> }
> >>
> >> @Override
> >> String *offsetSyncTopic*(String clusterAlias) {
> >> // offset-sync topic will be created on target cluster so it
> need to follow
> >> // naming convention of target cluster
> >> return nameTopicOnTarget(clusterAlias, "mm2-offset-sync",
> "internal");
> >> }
> >>
> >> @Override
> >> String *checkpointsTopic*(String clusterAlias) {
> >> // checkpoints topic is created on target cluster so it need to
> follow
> >> // naming convention of target cluster
> >> return nameTopicOnTarget(clusterAlias, "mm2-checkpoints",
> "internal");
> >> }
> >>
> >> private String *nameTopicOnTarget*(String prefix, String topic,
> String suffix) {
> >> return prefix + separator + topic + seprator + suffix;
> >> }
> >> }
> >>
> >> and MM2 configs will be
> >>
> >> *newCenterCluster.replication.policy.class=MyCustomReplicationPolicy*
> >>
> >> Mickael: I understand an interface gives a lot of flexibility but I'd
> >>> expect topic names to be relatively simple and known in advance in most
> >>> cases.
> >>>
> >>
> >> Gwen: How is it too complex?
> >>>
> >>
> >> The reason I opted for this solution wasn't about complexity but rather
> >> the number of configurations that MM2 already has. In addition to the
> point
> >> above regarding Mickael's future KIP to move offset-sync topic target
> >> cluster.
> >>
> >>
> >> Gwen: There is a discussion about how this gets more complicated in some
> >>> scenarios, but it was a bit abstract - is there a concrete case that
> shows
> >>> why the configuration is more complicated than implementing a plugin?
> >>>
> >>
> >> The use case I have in mind is something like my example above. Also
> >> considering that Mickael is planning to open a KIP to restrict the
> access
> >> to the source cluster and have the offset mapping topics on the target
> >> cluster this means using the ReplicationPolicy that handle naming
> policies
> >> at the target cluster makes it easier because if the target cluster has
> a
> >> restricted naming convention it will be applied on all topics created
> there.
> >>
> >> Another consideration is a future KIP I’ll be raising soon to abstract
> >> how MM2 creates topics on target cluster, say for example to integrate
> with
> >> a centralized resource management system. A custom ReplicationPolicy
> will
> >> give users more flexibility in this kind of integration and having to
> >> manage what can potentially be a lot less configuration.
> >>
> >>
> >> I’m not strongly attached to using an interface as the solution for
> >> naming internal topics however, I feel it will give us more flexibility
> >> with future KIPs.
> >>
> >> I would appreciate getting feedback from you both. And if the majority
> >> feels like the configurations are easier I can change the proposal to
> this.
> >>
> >> --
> >> Omnia
> >>
> >>
> >> On Sat, May 15, 2021 at 5:59 PM Omnia Ibrahim <o.g.h.ibra...@gmail.com>
> >> wrote:
> >>
> >>> Hey Gwen,
> >>> Thanks for having a look into the KIP, regard your question
> >>>
> >>>> is there a concrete case that shows why configuration is more
> >>>> complicated than implementing a plugin?
> >>>>
> >>>
> >>> The case I had in mind is where an organisation with medium-to-large
> >>> size have multiple teams running their own Kafka clusters without a
> >>> centralized team that runs Kafka and enforce the same rule for naming
> >>> resources everywhere.
> >>> In this environment, if the organization for example is trying to use
> >>> MM2 to migrate all their data into one place or the data is needed on
> both
> >>> clusters for any business use cases (like needs aggregate data from
> >>> different clusters), adding extra config for each internal topic will
> >>> increase the amount of configuration need to run MM2 for this case.
> >>>
> >>> The other concerns I have in general are
> >>>
> >>> 1. The popular usage of MM2 is replicating topics between clusters
> >>> running by the same team, in this case, it's most likely that if this
> team
> >>> has a naming topic's rule, this same rule will be applied to both
> >>> replicated and some of the internal topics of MM2. If we added config
> >>> like connect to each internal topic then these customers will end up
> adding
> >>> 4 configs just to handle the same naming rule, 1 to include customised
> >>> replication policy for naming replicated topics + extra 3 configs for
> the
> >>> internals to match the same rule.
> >>>
> >>> 2. The replication policy plugin already implemented in the MM2, and
> >>> many customers have already their own customised implementation
> (there're
> >>> few implementations flying around already for this policy in the
> community)
> >>> so we aren't adding extra configuration instead we are expanding the
> >>> responsibility of the policy.
> >>>
> >>> Am happy to make it align with connect configs if others disagree with
> >>> my concerns, at the end my number one goal is to make it flexible to
> name
> >>> these topics. I opt-in for an interface based solution so I can
> minimize
> >>> the number of config customers need to add.
> >>>
> >>> Omnia
> >>>
> >>>
> >>> On Thu, May 13, 2021 at 9:30 PM Gwen Shapira <g...@confluent.io.invalid
> >
> >>> wrote:
> >>>
> >>>> Hey, sorry for arriving late, but I have a question about the rejected
> >>>> alternative involving configuration.
> >>>>
> >>>> I may be missing something, but we are looking at 3 new configs (one
> for
> >>>> each topic). And this rejected alternative is basically identical to
> >>>> what
> >>>> Connect already does (you can choose names for internal topics using
> >>>> configs). How is it too complex? As a user, configuring 3 fields seems
> >>>> much
> >>>> simpler than implementing a class. As an admin, trusting to run
> >>>> someone's
> >>>> code is scary, but a config with topic name is very safe and easy to
> >>>> test
> >>>> and trust.
> >>>>
> >>>> There is a discussion about how this gets more complicated in some
> >>>> scenarios, but it was a bit abstract - is there a concrete case that
> >>>> shows
> >>>> why configuration is more complicated than implementing a plugin?
> >>>>
> >>>> Gwen
> >>>>
> >>>> On Fri, Apr 30, 2021 at 2:30 AM Omnia Ibrahim <
> o.g.h.ibra...@gmail.com>
> >>>> wrote:
> >>>>
> >>>> > Hi Ryanne, Can you vote for it here
> >>>> > https://www.mail-archive.com/dev@kafka.apache.org/msg113575.html as
> >>>> well,
> >>>> > please?
> >>>> >
> >>>> > On Fri, Apr 30, 2021 at 12:44 AM Ryanne Dolan <
> ryannedo...@gmail.com>
> >>>> > wrote:
> >>>> >
> >>>> > > Thanks Omnia. lgtm!
> >>>> > >
> >>>> > > Ryanne
> >>>> > >
> >>>> > > On Thu, Apr 29, 2021 at 10:50 AM Omnia Ibrahim <
> >>>> o.g.h.ibra...@gmail.com>
> >>>> > > wrote:
> >>>> > >
> >>>> > >> I updated the KIP
> >>>> > >>
> >>>> > >> On Thu, Apr 29, 2021 at 4:43 PM Omnia Ibrahim <
> >>>> o.g.h.ibra...@gmail.com>
> >>>> > >> wrote:
> >>>> > >>
> >>>> > >>> Sure, this would make it easier, we can make these functions
> >>>> returns
> >>>> > the
> >>>> > >>> original behaviour (<clusterAlias>.checkpoints.internal,
> >>>> > >>> "mm2-offset-syncs.<clusterAlias>.internal", heartbeat) without
> >>>> any
> >>>> > >>> customisation using `replication.policy.separator` and use the
> >>>> > separator in
> >>>> > >>> the DefaultReplicationPolicy
> >>>> > >>>
> >>>> > >>> On Wed, Apr 28, 2021 at 1:31 AM Ryanne Dolan <
> >>>> ryannedo...@gmail.com>
> >>>> > >>> wrote:
> >>>> > >>>
> >>>> > >>>> Thanks Omnia, makes sense to me.
> >>>> > >>>>
> >>>> > >>>> > Customers who have their customised ReplicationPolicy will
> >>>> need to
> >>>> > >>>> add the definition of their internal topics naming convention
> >>>> > >>>>
> >>>> > >>>> I wonder should we include default impls in the interface to
> >>>> avoid
> >>>> > that
> >>>> > >>>> requirement?
> >>>> > >>>>
> >>>> > >>>> Ryanne
> >>>> > >>>>
> >>>> > >>>> On Sun, Apr 25, 2021, 2:20 PM Omnia Ibrahim <
> >>>> o.g.h.ibra...@gmail.com>
> >>>> > >>>> wrote:
> >>>> > >>>>
> >>>> > >>>>> Hi Mickael and Ryanne,
> >>>> > >>>>> I updated the KIP to add these methods to the
> ReplicationPolicy
> >>>> > >>>>> instead of an extra interface to simplify the changes. Please
> >>>> have a
> >>>> > look
> >>>> > >>>>> and let me know your thoughts.
> >>>> > >>>>>
> >>>> > >>>>> Thanks
> >>>> > >>>>>
> >>>> > >>>>> On Tue, Mar 30, 2021 at 7:19 PM Omnia Ibrahim <
> >>>> > o.g.h.ibra...@gmail.com>
> >>>> > >>>>> wrote:
> >>>> > >>>>>
> >>>> > >>>>>> *(sorry forgot to Replay to All) *
> >>>> > >>>>>> Hi Ryanne,
> >>>> > >>>>>> It's a valid concern, I was trying to separate the concerns
> of
> >>>> > >>>>>> internal and replicated policy away from each other and to
> >>>> make the
> >>>> > code
> >>>> > >>>>>> readable as extending ReplicationPolicy to manage both
> >>>> internal and
> >>>> > >>>>>> replicated topic is a bit odd. Am not against simplifying
> >>>> things
> >>>> > out to
> >>>> > >>>>>> make ReplicationPolicy handling both at the end of the day if
> >>>> an
> >>>> > MM2 user
> >>>> > >>>>>> has a special naming convention for topics it will be
> >>>> affecting both
> >>>> > >>>>>> replicated and MM2 internal topics.
> >>>> > >>>>>>
> >>>> > >>>>>> For simplifying things we can extend `ReplicationPolicy` to
> the
> >>>> > >>>>>> following instead of adding an extra class
> >>>> > >>>>>>
> >>>> > >>>>>>> *public interface ReplicationPolicy {*
> >>>> > >>>>>>> String topicSource(String topic);
> >>>> > >>>>>>> String upstreamTopic(String topic);
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>> */** Returns heartbeats topic name.*/ String
> >>>> heartbeatsTopic();*
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>> * /** Returns the offset-syncs topic for given cluster
> >>>> alias. */
> >>>> > >>>>>>> String offsetSyncTopic(String targetAlias); /** Returns
> >>>> the
> >>>> > name
> >>>> > >>>>>>> checkpoint topic for given cluster alias. */ String
> >>>> > >>>>>>> checkpointTopic(String sourceAlias); *
> >>>> > >>>>>>>
> >>>> > >>>>>>> default String originalTopic(String topic) {
> >>>> > >>>>>>> String upstream = upstreamTopic(topic);
> >>>> > >>>>>>> if (upstream == null) {
> >>>> > >>>>>>> return topic;
> >>>> > >>>>>>> } else {
> >>>> > >>>>>>> return originalTopic(upstream);
> >>>> > >>>>>>> }
> >>>> > >>>>>>> }
> >>>> > >>>>>>>
> >>>> > >>>>>>>
> >>>> > >>>>>>> * /** Internal topics are never replicated. */
> >>>> > >>>>>>> isInternalTopic(String topic) *//the implementaion will be
> >>>> moved to
> >>>> > >>>>>>> `DefaultReplicationPolicy` to handle both kafka topics and
> MM2
> >>>> > internal
> >>>> > >>>>>>> topics.
> >>>> > >>>>>>> }
> >>>> > >>>>>>>
> >>>> > >>>>>>
> >>>> > >>>>>> On Fri, Mar 26, 2021 at 3:05 PM Ryanne Dolan <
> >>>> ryannedo...@gmail.com
> >>>> > >
> >>>> > >>>>>> wrote:
> >>>> > >>>>>>
> >>>> > >>>>>>> Omnia, have we considered just adding methods to
> >>>> ReplicationPolicy?
> >>>> > >>>>>>> I'm reluctant to add a new class because, as Mickael points
> >>>> out,
> >>>> > we'd need
> >>>> > >>>>>>> to carry it around in client code.
> >>>> > >>>>>>>
> >>>> > >>>>>>> Ryanne
> >>>> > >>>>>>>
> >>>> > >>>>>>> On Fri, Feb 19, 2021 at 8:31 AM Mickael Maison <
> >>>> > >>>>>>> mickael.mai...@gmail.com> wrote:
> >>>> > >>>>>>>
> >>>> > >>>>>>>> Hi Omnia,
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> Thanks for the clarifications.
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> - I'm still a bit uneasy with the overlap between these 2
> >>>> methods
> >>>> > as
> >>>> > >>>>>>>> currently `ReplicationPolicy.isInternalTopic` already
> >>>> handles MM2
> >>>> > >>>>>>>> internal topics. Should we make it only handle Kafka
> internal
> >>>> > topics
> >>>> > >>>>>>>> and `isMM2InternalTopic()` only handle MM2 topics?
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> - I'm not sure I understand what this method is used for.
> >>>> There
> >>>> > are
> >>>> > >>>>>>>> no
> >>>> > >>>>>>>> such methods for the other 2 topics (offset-sync and
> >>>> heartbeat).
> >>>> > >>>>>>>> Also
> >>>> > >>>>>>>> what happens if there are other MM2 instances using
> different
> >>>> > naming
> >>>> > >>>>>>>> schemes in the same cluster. Do all instances have to know
> >>>> about
> >>>> > the
> >>>> > >>>>>>>> other naming schemes? What are the expected issues if they
> >>>> don't?
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> - RemoteClusterUtils is a client-side utility so it does
> not
> >>>> have
> >>>> > >>>>>>>> access to the MM2 configuration. Since this new API can
> >>>> affect the
> >>>> > >>>>>>>> name of the checkpoint topic, it will need to be used
> >>>> client-side
> >>>> > >>>>>>>> too
> >>>> > >>>>>>>> so users can find the checkpoint topic name. I had to
> >>>> realized
> >>>> > this
> >>>> > >>>>>>>> was the case.
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> Thanks
> >>>> > >>>>>>>>
> >>>> > >>>>>>>> On Mon, Feb 15, 2021 at 9:33 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com> wrote:
> >>>> > >>>>>>>> >
> >>>> > >>>>>>>> > Hi Mickael, did you have some time to check my answer?
> >>>> > >>>>>>>> >
> >>>> > >>>>>>>> > On Thu, Jan 21, 2021 at 10:10 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com> wrote:
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> Hi Mickael,
> >>>> > >>>>>>>> >> Thanks for taking another look into the KIP, regards
> your
> >>>> > >>>>>>>> questions
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> - I believe we need both "isMM2InternalTopic" and
> >>>> > >>>>>>>> `ReplicationPolicy.isInternalTopic` as
> >>>> > `ReplicationPolicy.isInternalTopic`
> >>>> > >>>>>>>> does check if a topic is Kafka internal topic, while
> >>>> > `isMM2InternalTopic`
> >>>> > >>>>>>>> is just focusing if a topic is MM2 internal topic or
> >>>> not(which is
> >>>> > >>>>>>>> heartbeat/checkpoint/offset-sync). The fact that the
> >>>> default for
> >>>> > MM2
> >>>> > >>>>>>>> internal topics matches "ReplicationPolicy.isInternalTopic"
> >>>> will
> >>>> > not be an
> >>>> > >>>>>>>> accurate assumption anymore once we implement this KIP.
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> - "isCheckpointTopic" will detect all checkpoint topics
> >>>> for all
> >>>> > >>>>>>>> MM2 instances this is needed for "MirrorClient.
> >>>> checkpointTopics"
> >>>> > which
> >>>> > >>>>>>>> originally check if the topic name ends with
> >>>> > CHECKPOINTS_TOPIC_SUFFIX. So
> >>>> > >>>>>>>> this method just to keep the same functionality that
> >>>> originally
> >>>> > exists in
> >>>> > >>>>>>>> MM2
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> - "checkpointTopic" is used in two places 1. At topic
> >>>> creation
> >>>> > >>>>>>>> in "MirrorCheckpointConnector.createInternalTopics" which
> >>>> use
> >>>> > >>>>>>>> "sourceClusterAlias() + CHECKPOINTS_TOPIC_SUFFIX" and 2. At
> >>>> > >>>>>>>> "MirrorClient.remoteConsumerOffsets" which is called by
> >>>> > >>>>>>>> "RemoteClusterUtils.translateOffsets" the cluster alias
> >>>> here
> >>>> > referred to
> >>>> > >>>>>>>> as "remoteCluster" where the topic name is
> >>>> "remoteClusterAlias +
> >>>> > >>>>>>>> CHECKPOINTS_TOPIC_SUFFIX" (which is an argument in
> >>>> > RemoteClusterUtils, not
> >>>> > >>>>>>>> a config) This why I called the variable cluster instead of
> >>>> > source and
> >>>> > >>>>>>>> instead of using the config to figure out the cluster
> aliases
> >>>> > from config
> >>>> > >>>>>>>> as we use checkpoints to keep `RemoteClusterUtils`
> >>>> compatible for
> >>>> > existing
> >>>> > >>>>>>>> users. I see a benefit of just read the config a find out
> the
> >>>> > cluster
> >>>> > >>>>>>>> aliases but on the other side, I'm not sure why
> >>>> > "RemoteClusterUtils"
> >>>> > >>>>>>>> doesn't get the name of the cluster from the properties
> >>>> instead
> >>>> > of an
> >>>> > >>>>>>>> argument, so I decided to keep it just for compatibility.
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> Hope these answer some of your concerns.
> >>>> > >>>>>>>> >> Best
> >>>> > >>>>>>>> >> Omnia
> >>>> > >>>>>>>> >>
> >>>> > >>>>>>>> >> On Thu, Jan 21, 2021 at 3:37 PM Mickael Maison <
> >>>> > >>>>>>>> mickael.mai...@gmail.com> wrote:
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> Hi Omnia,
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> Thanks for the updates. Sorry for the delay but I have
> a
> >>>> few
> >>>> > >>>>>>>> more
> >>>> > >>>>>>>> >>> small questions about the API:
> >>>> > >>>>>>>> >>> - Do we really need "isMM2InternalTopic()"? There's
> >>>> already
> >>>> > >>>>>>>> >>> "ReplicationPolicy.isInternalTopic()". If so, we need
> to
> >>>> > >>>>>>>> explain the
> >>>> > >>>>>>>> >>> difference between these 2 methods.
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> - Is "isCheckpointTopic()" expected to detect all
> >>>> checkpoint
> >>>> > >>>>>>>> topics
> >>>> > >>>>>>>> >>> (for all MM2 instances) or only the ones for this
> >>>> connector
> >>>> > >>>>>>>> instance.
> >>>> > >>>>>>>> >>> If it's the later, I wonder if we could do without the
> >>>> method.
> >>>> > >>>>>>>> As this
> >>>> > >>>>>>>> >>> interface is only called by MM2, we could first call
> >>>> > >>>>>>>> >>> "checkpointTopic()" and check if that's equal to the
> >>>> topic
> >>>> > we're
> >>>> > >>>>>>>> >>> checking. If it's the former, we don't really know
> topic
> >>>> names
> >>>> > >>>>>>>> other
> >>>> > >>>>>>>> >>> MM2 instances may be using!
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> - The 3 methods returning topic names have different
> >>>> APIs:
> >>>> > >>>>>>>> >>> "heartbeatsTopic()" takes no arguments,
> >>>> "offsetSyncTopic()"
> >>>> > >>>>>>>> takes the
> >>>> > >>>>>>>> >>> target cluster alias and "checkpointTopic()" takes
> >>>> > >>>>>>>> "clusterAlias"
> >>>> > >>>>>>>> >>> (which one is it? source or target?). As the interface
> >>>> extends
> >>>> > >>>>>>>> >>> Configurable, maybe we could get rid of all the
> >>>> arguments and
> >>>> > >>>>>>>> use the
> >>>> > >>>>>>>> >>> config to find the cluster aliases. WDYT?
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> These are minor concerns, just making sure I fully
> >>>> understand
> >>>> > >>>>>>>> how the
> >>>> > >>>>>>>> >>> API is expected to be used. Once these are cleared,
> I'll
> >>>> be
> >>>> > >>>>>>>> happy to
> >>>> > >>>>>>>> >>> vote for this KIP.
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> Thanks
> >>>> > >>>>>>>> >>>
> >>>> > >>>>>>>> >>> On Fri, Jan 8, 2021 at 12:06 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com> wrote:
> >>>> > >>>>>>>> >>> >
> >>>> > >>>>>>>> >>> > Hi Mickael,
> >>>> > >>>>>>>> >>> > Did you get time to review the changes to the KIP? If
> >>>> you
> >>>> > >>>>>>>> okay with it could you vote for the KIP here ttps://
> >>>> > >>>>>>>> www.mail-archive.com/dev@kafka.apache.org/msg113575.html?
> >>>> > >>>>>>>> >>> > Thanks
> >>>> > >>>>>>>> >>> >
> >>>> > >>>>>>>> >>> > On Thu, Dec 10, 2020 at 2:19 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com> wrote:
> >>>> > >>>>>>>> >>> >>
> >>>> > >>>>>>>> >>> >> Hi Mickael,
> >>>> > >>>>>>>> >>> >> 1) That's right the interface and default
> >>>> implementation
> >>>> > >>>>>>>> will in mirror-connect
> >>>> > >>>>>>>> >>> >> 2) Renaming the interface should be fine too
> >>>> especially if
> >>>> > >>>>>>>> you planning to move other functionality related to the
> >>>> creation
> >>>> > there, I
> >>>> > >>>>>>>> can edit this
> >>>> > >>>>>>>> >>> >>
> >>>> > >>>>>>>> >>> >> if you are okay with that please vote for the KIP
> here
> >>>> > >>>>>>>>
> >>>> https://www.mail-archive.com/dev@kafka.apache.org/msg113575.html
> >>>> > >>>>>>>> >>> >>
> >>>> > >>>>>>>> >>> >>
> >>>> > >>>>>>>> >>> >> Thanks
> >>>> > >>>>>>>> >>> >> Omnia
> >>>> > >>>>>>>> >>> >> On Thu, Dec 10, 2020 at 12:58 PM Mickael Maison <
> >>>> > >>>>>>>> mickael.mai...@gmail.com> wrote:
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> Hi Omnia,
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> Thank you for the reply, it makes sense.
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> A couple more comments:
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> 1) I'm assuming the new interface and default
> >>>> > >>>>>>>> implementation will be
> >>>> > >>>>>>>> >>> >>> in the mirror-client project? as the names of some
> of
> >>>> > these
> >>>> > >>>>>>>> topics are
> >>>> > >>>>>>>> >>> >>> needed by RemoteClusterUtils on the client-side.
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> 2) I'm about to open a KIP to specify where the
> >>>> > >>>>>>>> offset-syncs topic is
> >>>> > >>>>>>>> >>> >>> created by MM2. In restricted environments, we'd
> >>>> prefer
> >>>> > MM2
> >>>> > >>>>>>>> to only
> >>>> > >>>>>>>> >>> >>> have read access to the source cluster and have the
> >>>> > >>>>>>>> offset-syncs on
> >>>> > >>>>>>>> >>> >>> the target cluster. I think allowing to specify the
> >>>> > cluster
> >>>> > >>>>>>>> where to
> >>>> > >>>>>>>> >>> >>> create that topic would be a natural extension of
> the
> >>>> > >>>>>>>> interface you
> >>>> > >>>>>>>> >>> >>> propose here.
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> So I wonder if your interface could be named
> >>>> > >>>>>>>> InternalTopicsPolicy?
> >>>> > >>>>>>>> >>> >>> That's a bit more generic than
> >>>> InternalTopicNamingPolicy.
> >>>> > >>>>>>>> That would
> >>>> > >>>>>>>> >>> >>> also match the configuration setting,
> >>>> > >>>>>>>> internal.topics.policy.class,
> >>>> > >>>>>>>> >>> >>> you're proposing.
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> Thanks
> >>>> > >>>>>>>> >>> >>>
> >>>> > >>>>>>>> >>> >>> On Thu, Dec 3, 2020 at 10:15 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com> wrote:
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > Hi Mickael,
> >>>> > >>>>>>>> >>> >>> > Thanks for your feedback!
> >>>> > >>>>>>>> >>> >>> > Regards your question about having more
> >>>> configurations,
> >>>> > I
> >>>> > >>>>>>>> considered adding
> >>>> > >>>>>>>> >>> >>> > configuration per each topic however this meant
> >>>> adding
> >>>> > >>>>>>>> more configurations
> >>>> > >>>>>>>> >>> >>> > for MM2 which already have so many, also the more
> >>>> > >>>>>>>> complicated and advanced
> >>>> > >>>>>>>> >>> >>> > replication pattern you have between clusters the
> >>>> more
> >>>> > >>>>>>>> configuration lines
> >>>> > >>>>>>>> >>> >>> > will be added to your MM2 config which isn't
> going
> >>>> to be
> >>>> > >>>>>>>> pretty if you
> >>>> > >>>>>>>> >>> >>> > don't have the same topics names across your
> >>>> clusters.
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > Also, it added more complexity to the
> >>>> implementation as
> >>>> > >>>>>>>> MM2 need to
> >>>> > >>>>>>>> >>> >>> > 1- identify if a topic is checkpoints so we could
> >>>> list
> >>>> > >>>>>>>> the checkpoints
> >>>> > >>>>>>>> >>> >>> > topics in MirrorMaker 2 utils as one cluster
> could
> >>>> have
> >>>> > X
> >>>> > >>>>>>>> numbers
> >>>> > >>>>>>>> >>> >>> > checkpoints topics if it's connected to X
> >>>> clusters, this
> >>>> > >>>>>>>> is done right now
> >>>> > >>>>>>>> >>> >>> > by listing any topic with suffix
> >>>> > `.checkpoints.internal`.
> >>>> > >>>>>>>> This could be
> >>>> > >>>>>>>> >>> >>> > done by add `checkpoints.topic.suffix` config but
> >>>> this
> >>>> > >>>>>>>> would make an
> >>>> > >>>>>>>> >>> >>> > assumption that checkpoints will always have a
> >>>> suffix
> >>>> > >>>>>>>> also having a suffix
> >>>> > >>>>>>>> >>> >>> > means that we may need a separator as well to
> >>>> > concatenate
> >>>> > >>>>>>>> this suffix with
> >>>> > >>>>>>>> >>> >>> > a prefix to identify source cluster name.
> >>>> > >>>>>>>> >>> >>> > 2- identify if a topic is internal, so it
> >>>> shouldn't be
> >>>> > >>>>>>>> replicated or track
> >>>> > >>>>>>>> >>> >>> > checkpoints for it, right now this is relaying on
> >>>> > >>>>>>>> disallow topics with
> >>>> > >>>>>>>> >>> >>> > `.internal` suffix to be not replicated and not
> >>>> tracked
> >>>> > >>>>>>>> in checkpoints but
> >>>> > >>>>>>>> >>> >>> > with making topics configurable we need a way to
> >>>> define
> >>>> > >>>>>>>> what is an internal
> >>>> > >>>>>>>> >>> >>> > topic. This could be done by making using a list
> >>>> of all
> >>>> > >>>>>>>> internal topics
> >>>> > >>>>>>>> >>> >>> > have been entered to the configuration.
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > So having an interface seemed easier and also
> give
> >>>> more
> >>>> > >>>>>>>> flexibility for
> >>>> > >>>>>>>> >>> >>> > users to define their own topics name, define
> what
> >>>> is
> >>>> > >>>>>>>> internal topic means,
> >>>> > >>>>>>>> >>> >>> > how to find checkpoints topics and it will be one
> >>>> line
> >>>> > >>>>>>>> config for each
> >>>> > >>>>>>>> >>> >>> > herder, also it more consistence with MM2 code as
> >>>> MM2
> >>>> > >>>>>>>> config have
> >>>> > >>>>>>>> >>> >>> > TopicFilter, ReplicationPolicy, GroupFilter, etc
> as
> >>>> > >>>>>>>> interface and they can
> >>>> > >>>>>>>> >>> >>> > be overridden by providing a custom
> implementation
> >>>> for
> >>>> > >>>>>>>> them or have some
> >>>> > >>>>>>>> >>> >>> > config that change their default implementations.
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > Hope this answer your question. I also updated
> the
> >>>> KIP
> >>>> > to
> >>>> > >>>>>>>> add this to the
> >>>> > >>>>>>>> >>> >>> > rejected solutions.
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > On Thu, Dec 3, 2020 at 3:19 PM Mickael Maison <
> >>>> > >>>>>>>> mickael.mai...@gmail.com>
> >>>> > >>>>>>>> >>> >>> > wrote:
> >>>> > >>>>>>>> >>> >>> >
> >>>> > >>>>>>>> >>> >>> > > Hi Omnia,
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> >>> >>> > > Thanks for the KIP. Indeed being able to
> >>>> configure
> >>>> > >>>>>>>> MM2's internal
> >>>> > >>>>>>>> >>> >>> > > topic names would be a nice improvement.
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> >>> >>> > > Looking at the KIP, I was surprised you propose
> >>>> an
> >>>> > >>>>>>>> interface to allow
> >>>> > >>>>>>>> >>> >>> > > users to specify names. Have you considered
> >>>> making
> >>>> > >>>>>>>> names changeable
> >>>> > >>>>>>>> >>> >>> > > via configurations? If so, we should definitely
> >>>> > mention
> >>>> > >>>>>>>> it in the
> >>>> > >>>>>>>> >>> >>> > > rejected alternatives as it's the first method
> >>>> that
> >>>> > >>>>>>>> comes to mind.
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> >>> >>> > > I understand an interface gives a lot of
> >>>> flexibility
> >>>> > >>>>>>>> but I'd expect
> >>>> > >>>>>>>> >>> >>> > > topic names to be relatively simple and known
> in
> >>>> > >>>>>>>> advance in most
> >>>> > >>>>>>>> >>> >>> > > cases.
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> >>> >>> > > I've not checked all use cases but something
> like
> >>>> > below
> >>>> > >>>>>>>> felt appropriate:
> >>>> > >>>>>>>> >>> >>> > > clusters = primary,backup
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> primary->backup.offsets-sync.topic=backup.mytopic-offsets-
> >>>> sync
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>> >>> >>> > > On Tue, Dec 1, 2020 at 3:36 PM Omnia Ibrahim <
> >>>> > >>>>>>>> o.g.h.ibra...@gmail.com>
> >>>> > >>>>>>>> >>> >>> > > wrote:
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > > > Hey everyone,
> >>>> > >>>>>>>> >>> >>> > > > Please take a look at KIP-690:
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>>
> >>>> >
> >>>>
> https://cwiki.apache.org/confluence/display/KAFKA/KIP-690%3A+Add+additional+configuration+to+control+MirrorMaker+2+internal+topics+naming+convention
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > > > Thanks for your feedback and support.
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > > > Omnia
> >>>> > >>>>>>>> >>> >>> > > >
> >>>> > >>>>>>>> >>> >>> > >
> >>>> > >>>>>>>>
> >>>> > >>>>>>>
> >>>> >
> >>>>
> >>>>
> >>>> --
> >>>> Gwen Shapira
> >>>> Engineering Manager | Confluent
> >>>> 650.450.2760 | @gwenshap
> >>>> Follow us: Twitter | blog
> >>>>
> >>>
>
