Il giorno lun 26 giu 2023 alle ore 09:21 Yubiao Feng
<yubiao.f...@streamnative.io.invalid> ha scritto:
>
> Hi Yan,Asaf
>
> > I want to add only one step to your plan.
> > If you introduce this flag in Y.X, then in Y.(X+1),
> > let's remove this flag
> > and keep the "true" value as the behavior.
>
> I agree with Asaf
+1
Enrico
>
> Thanks
> Yubiao Feng
>
> On Mon, Jun 19, 2023 at 9:57 AM horizonzy <horizo...@apache.org> wrote:
>
> > Background
> >
> > In the Pulsar, it has two features:
> >
> > -
> >
> > The first feature allows users to set group and rack information for
> > bookies using pulsar-admin bookies set-bookie-rack.
> >
> > Here, users set bookie1 to bookie5 to the default group and bookie6 to
> > bookie10 to the share group using commands, they don't care about rack
> > information, they only care about which group the bookie belongs to.
> >
> > default={bookie1:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie2:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie3:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie4:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie5:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null)}
> >
> > _shared_={bookie6:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie7:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie8:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie9:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null), bookie10:3181=BookieInfoImpl(rack=default-rack,
> > hostname=null)}
> >
> >
> > -
> >
> > The second feature allows users to set the priority of traffic for a
> > namespace, where traffic is directed to the primary group first and
> > then to
> > the secondary group. Users can set this priority using pulsar-admin
> > ns-isolation-policy set --namespaces public/default --primary "group"
> > --secondary "group".
> >
> > Here, users set the primary group of the /public/default namespace to
> > "share" using a command.
> >
> > {
> > "bookkeeperAffinityGroupPrimary" : "share"
> > }
> >
> > After this work is completed, all traffic under the /public/default
> > namespace will be directed to bookie6-10 in the "share" group.
> >
> > Drawbacks
> >
> > After a period of time, users added some new bookies [bk11, bk12, bk13,
> > bk14, bk15] to the bookie cluster, they found that some traffic under the
> > /public/default namespace was directed to the newly added machines. After
> > investigation, we eventually found that this was a defect in the working
> > mechanism of bookkeeperAffinityGroupPrimary.
> >
> > *bookkeeperAffinityGroupPrimary work mechanism*
> >
> > All bookies in the cluster: bk1-bk15.
> >
> > Here are the steps of the broker pick bookies.
> >
> > 1.
> >
> > Get the bookie rack info config default: [bk1, bk2, bk3, bk4, bk5];
> > share:
> > [bk6, bk7, bk8, bk9, bk10]
> > 2.
> >
> > Exclude the bookies which are not the bookkeeperAffinityGroupPrimary
> > (share).
> > 3.
> >
> > Exclude the default group bookies [bk1, bk2, bk3, bk4, bk5].
> > 4.
> >
> > Pick bookies from the remaining bookies [bk6, bk7, bk8, bk9, bk10, bk11,
> > bk12, bk13, bk14, bk15]
> >
> > Therefore, some traffic may go to bk11-bk15, which is not what the users
> > expect. The reason is that the new bookies, bk11 to bk15, did not have rack
> > information set and were not part of any group.
> >
> > We provided a workaround for users to set the rack information for bk11 to
> > bk15 in advance using the command pulsar-admin bookies set-bookie-rack
> > before starting them. After user adopting this workaround, the traffic
> > worked as expected.
> >
> > For user, it may be a bit inconvenient as they need to set rack information
> > in advance before bringing new bookies online. In scenarios where there are
> > strict limitations on traffic, if the bookie operation and maintenance
> > personnel overlook this step, it could cause problems.
> >
> > Improvement
> >
> > I would like to introduce a new configuration strict for
> > bookkeeperAffinityGroupPrimary. The default value for this configuration is
> > false, which means that for old users upgrading to the new version, the
> > logic will remain the same and bookies without rack information will not be
> > constrained.
> >
> > If users manually set strict to true using the command pulsar-admin
> > ns-isolation-policy set --namespaces public/default --primary "group"
> > --secondary "group" --strict true, when the broker selects a bookie, it
> > will only choose from the bookies in the primary group. If there are not
> > enough bookies in the primary group, it will choose from the bookies in the
> > secondary group. If there are not enough bookies in either group, an
> > exception will be thrown. Bookies without rack information set using
> > pulsar-admin
> > bookies set-bookie-rack will not be selected.
> >
> > Compatibility
> >
> > When users upgrade from the old version to the new version, the working
> > mechanism of bookkeeperAffinityGroupPrimary remains the same as before.
> > When users upgrade to the new version and set strict to true using the
> > command pulsar-admin ns-isolation-policy set --namespaces public/default
> > --primary "group" --secondary "group" --strict true, and then roll back to
> > the old version, the broker should be able to correctly parse the
> > ns-isolation-policy configuration.
> >
