Any time Yu Li!

No meeting tomorrow... Lets meet next week, the 10th.

Thanks,
S

On Wed, Jul 28, 2021 at 11:25 PM Yu Li <[email protected]> wrote:

> Thanks for the notes and efforts Stack, it's pretty helpful to know the
> progress and latest status of the work!
>
> Best Regards,
> Yu
>
>
> On Wed, 28 Jul 2021 at 12:13, Stack <[email protected]> wrote:
>
> > Note, no meeting tomorrow. We'll meet next week on the 4th or 5th of
> > August.
> > Thanks,
> > S
> >
> > On Thu, Jul 22, 2021 at 8:53 PM Stack <[email protected]> wrote:
> >
> > > Notes from yesterday's meeting (attendees, please amend if I
> misrepresent
> > > or if you have anything extra to add!)
> > >
> > > Split Meta Design Reset Status
> > >
> > > Wed Jul 21 21:24:38 PDT 2021
> > >
> > > Attendees: Bharath, Stack, Duo, and Francis
> > >
> > > We went over the new updates to the Brainstorming [1] section under
> > >
> > > Design in the Super Split Meta Design doc [2].
> > >
> > > First was the new addition, 4.1.2 Extend (& Move) ConnectionRegistry;
> > hide
> > >
> > > ROOT from Client [3]. In particular, filling out how "ROOT" might be
> > >
> > > implemented behind the new API in ConnectionRegistry. On option 1.,
> > >
> > > replicating master-local Region to RegionServers, options considered
> > >
> > > included
> > >
> > >  * Listener on master-local Region WAL to replicate.
> > >
> > >  * Perhaps Read-Replica but master-local is not an actual Region
> > >
> > >  * Needs to be incremental edits because ROOT could get too big to ship
> > >
> > >    in a lump; need to visit how...
> > >
> > >  * Possibly in-memory-only Regions on RS replicated from master-local
> > >
> > >    Region via WAL tailing <= [email protected]
> > >
> > >  * Which RegionServers? Those hosting ROOT replicas?
> > >
> > >  * How to bootstrap? Failure scenarios.
> > >
> > >  * This would be a new replication system alongside current; could
> > >
> > >    evolve to replace/improve old?
> > >
> > > Duo offered to look into means of replicating the master-local Region
> > >
> > > out to RegionServers.
> > >
> > > Next up was discussion constrasting ROOT as a standalone table vs
> > >
> > > First-meta Region-as-Root (see 4.1.1 hbase:meta,,1 as ROOT [4]); i.e.
> > >
> > > options 2 and 3 for how we'd implement a ROOT. One item that came up
> > >
> > > was whether a need to specify one replica count for a ROOT table vs
> > >
> > > another for hbase:meta. If so, then it would be argument for ROOT as
> > >
> > > standalone table (Others of us argued it not a concern of consequence).
> > >
> > > If ROOT access is behind a new simple API in ConnectionRegistry, how
> > >
> > > to stop clients reading hbase:meta table if not Master or fronted by
> > >
> > > a ConnectionRegistry request? (Should be able to switch on client
> > >
> > > identity/source). One suggestion for First-meta-Region-as-ROOT was
> > >
> > > NOT returning the first Region to the client post-meta split when
> > >
> > > accessing via the simple API. Some concern this would confuse old
> > >
> > > Clients (Francis was going to take a look).
> > >
> > > Moved to discussion how we'd move ConnectionRegistry from
> > >
> > > hosted-by-Master to hosted-by-RegionServers. How to bootstrap such a
> > >
> > > system came up? Where do clients go? How do they know which
> > >
> > > RegionServers (special regionserver group?  Every RS fields
> > >
> > > ConnectionRegistry requests but only designated core serve the ROOT
> > >
> > > lookup APIs?). This was a TODO.
> > >
> > > This led naturally into 4.1.5 System RS group for client meta services
> > >
> > > [5], a new addition under Brainstorming. Discussion. Bharath to look
> > >
> > > into feedback.
> > >
> > > On the end of the discussion, group expressed support for adding
> > >
> > > simple API to the ConnectionRegistry to hide ROOT implementation
> > >
> > > detail from client. Support was expressed for moving ConnectionRegistry
> > >
> > > from Master to RegionServers. Intent is to move forward on design of
> > >
> > > these pieces: e.g. how client bootstraps.
> > >
> > > Support was expressed for getting at least the bones of a split meta
> > >
> > > into an hbase3 before the RCs.
> > >
> > > Where we'd actually store hbase:meta Region locations -- i.e. how a
> > >
> > > "ROOT' would be implemented -- was for our next meeting informed by
> > >
> > > research of the various approaches noted mostly above. It was
> > >
> > > also thought that the new ConnectionRegistry should not preclude
> > >
> > > making progress on the "ROOT" implementation.
> > >
> > > Will post notice of next meeting (next Weds or the one
> > >
> > > following).
> > >
> > > 1.
> > >
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.wr0fwvw06j7n
> > >
> > > 2.
> > >
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.9s666p6no9cq
> > >
> > > 3.
> > >
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.90th11txi153
> > >
> > > 4.
> > >
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.ikbhxlcthjle
> > >
> > > 5.
> > >
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.utoenf10t05b
> > >
> > > On Tue, Jul 20, 2021 at 11:00 AM Stack <[email protected]> wrote:
> > >
> > >> Lets meet tomorrow. Please review the design doc
> "Design/Brainstorming"
> > >> Section 4.1 [1] before the meeting if you can (No harm if a refresh of
> > the
> > >> requirements section while you are at it).
> > >>
> > >> Topic: Split Meta Design Reset Status
> > >> Time: Jul 21, 2021 05:00 PM Pacific Time (US and Canada)
> > >>
> > >> Join Zoom Meeting
> > >>
> >
> https://us04web.zoom.us/j/77318920525?pwd=OFZXZFVPSHJLaGNsby9SN25OV1F2Zz09
> > >>
> > >> Meeting ID: 773 1892 0525
> > >> Passcode: hbase
> > >>
> > >> Thanks,
> > >> S
> > >>
> > >> 1. 1.
> > >>
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.wr0fwvw06j7n
> > >>
> > >> On Thu, Jul 8, 2021 at 1:04 PM Stack <[email protected]> wrote:
> > >>
> > >>> Meeting notes (Meeting happend after I figured the zoom had a
> 'waiting
> > >>> room' -- sorry Duo)
> > >>>
> > >>> Split Meta Status Zoom Meeting
> > >>> Wed Jul  7, 2021 @ 5pm for ~90minutes
> > >>> Attendees: Duo, Francis, Stack, and Clay
> > >>> Agenda: Mainly talk about the one-pager design and PoC proposed in
> [2]
> > >>> and added to the
> > >>> split-meta design doc here [1] (hereafter, the 'hbase:meta,,1 as
> ROOT'
> > >>> approach)
> > >>>
> > >>> Duo suggested no advantage treating the first meta of hbase:meta
> table
> > >>> special; as a "root"
> > >>> and other comments (see remarks in [2]).
> > >>>
> > >>> Some pushback. When meta is NOT split, all works as it did before
> (big
> > >>> on backward-compatible).
> > >>>
> > >>> Duo suggested just intro a ROOT table altogether rather than treat
> the
> > >>> first Region
> > >>> in the hbase:meta table as a 'root' and then mirror to zk the first
> > meta
> > >>> region; if no
> > >>> split, then old clients should just work even though now hbase
> cluster
> > >>> has a ROOT table.
> > >>> Discussion. If no split, what's to do, etc.?
> > >>>
> > >>> Duo expressed concern that if split-meta is not on always -- enabled
> > >>> optionally -- then
> > >>> the code path will not see exercise and split-meta will likely fail
> and
> > >>> go the way of
> > >>> prefix tree and distributed log replay -- a feature that failed,
> > >>> cluttered up the
> > >>> code base, and only later was removed. Discussion. Was allowed this
> > >>> could happen.
> > >>> Counter examples: RegionServer Groups. A few of the attendees
> > >>> volunteered they need
> > >>> split meta for their production so would try to see it through.
> > >>>
> > >>> Some back and forth. Duo allowed that merit to the 'hbase:meta,,1 as
> > >>> ROOT' if we don't
> > >>> split; not much changes.
> > >>>
> > >>> Comment on the PoC that its all
> > >>>
> > >>>   if 'first special meta region' do this
> > >>>   else do something else...
> > >>>
> > >>> (all over the codebase) but it was suggested that this will be the
> case
> > >>> if ROOT table
> > >>> added also and argued any implementation will have this issue (if
> ROOT
> > >>> then....) and
> > >>> THAT ugly 'root' comparator too whether a ROOT table or the
> > >>>  'hbase:meta,,1 as ROOT'
> > >>> approach.
> > >>>
> > >>> Clay asking if meta is a bottleneck (Clay played the 'operator' and
> > >>> 'new-to-the-topic'
> > >>> roles). Some discussion around how indeed it is and why we want to
> > split
> > >>> meta at all.
> > >>>
> > >>> Clay mentioned how Master is inline for data now (Master-hosted
> > >>> Registry)....
> > >>> Discussion. Hopefully temporary state -- Registry doesn't need to be
> > >>> hosted on
> > >>> Master -- and Master will return to its background role -- soon.
> > >>>
> > >>> Clay brought up rollback after meta split. Discussion. Some agreement
> > it
> > >>> could be done for
> > >>> 'hbase:meta,,1 as ROOT' approach (but would be UGLY!). If root table
> > and
> > >>> client had
> > >>> started to use ROOT, it might be harder...
> > >>>
> > >>> Duo suggested that we not change the client at all; that client stays
> > >>> same however split
> > >>> meta is implemented (with addition of a root table or using
> > >>> hbase:meta,,1 as 'root').
> > >>> This sounded attractive. We discussed how this could be done in a
> > >>> backward compatible way;
> > >>> add simple location lookup API to Registry...A write-up on how this
> > >>> might work will be posted
> > >>> in next day or so for others to review (Need to figure getting
> Registry
> > >>> off Master).
> > >>>
> > >>> Clay suggested, as an operator, how he thought the split meta should
> > >>> roll out. One of us
> > >>> claimed this described the 'hbase:meta,,1 as ROOT' approach.
> > >>>
> > >>> Duo had to go to work so we called it quits and said we'd meet again
> > >>> same time, next week.
> > >>>
> > >>> 1.
> > >>>
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.ikbhxlcthjle
> > >>> 2. https://issues.apache.org/jira/browse/HBASE-25761
> > >>>
> > >>> On Wed, Jul 7, 2021 at 5:09 PM 张铎(Duo Zhang) <[email protected]>
> > >>> wrote:
> > >>>
> > >>>> Is it only me? I tried to join the meeting but it always tell me
> that
> > I
> > >>>> need to wait for the presenter to invite me to join...
> > >>>>
> > >>>> Stack <[email protected]> 于2021年7月8日周四 上午1:04写道:
> > >>>>
> > >>>> > Short notice but reminder that this meeting is today at 5pm PST
> (We
> > >>>> talked
> > >>>> > of doing it earlier but in the end lets just keep the original 5pm
> > >>>> time).
> > >>>> > Thanks,
> > >>>> > S
> > >>>> >
> > >>>> > On Tue, Jul 6, 2021 at 11:36 AM Stack <[email protected]> wrote:
> > >>>> >
> > >>>> > > Lets do a quick chat on current state of hbase split-meta
> project.
> > >>>> > >
> > >>>> > > Francis has posted a suggested one-pager design in HBASE-25761
> > which
> > >>>> > would
> > >>>> > > be good to review before the meeting if you can. Lets discuss
> this
> > >>>> and
> > >>>> > any
> > >>>> > > other suggestions for moving the project forward.
> > >>>> > >
> > >>>> > > Meeting details below.
> > >>>> > >
> > >>>> > > Thanks,
> > >>>> > > S
> > >>>> > >
> > >>>> > > Topic Split Meta Design Reset Status
> > >>>> > > Description Review one-pager design attached to
> > >>>> > > https://issues.apache.org/jira/browse/HBASE-25761
> > >>>> > > Time Jul 7, 2021 05:00 PM Pacific Time (US and Canada)
> > >>>> > >
> > >>>> > > Meeting ID 736 3907 8852
> > >>>> > > Security
> > >>>> > > Passcode *hbase* Hide
> > >>>> > > Waiting Room
> > >>>> > > Invite Link
> > >>>> > >
> > >>>> >
> > >>>>
> >
> https://us04web.zoom.us/j/73639078852?pwd=eHE2VCt2RG5FV2V2RXVNazlPVTVyQT09
> > >>>> > Copy
> > >>>> > > Invitation
> > >>>> > >
> > >>>> > > On Mon, Mar 22, 2021 at 4:28 PM Stack <[email protected]> wrote:
> > >>>> > >
> > >>>> > >> Now the requirements are in [1], we're going to move to the
> next
> > >>>> stage
> > >>>> > --
> > >>>> > >> actual design for split-meta -- and have set up a chat for this
> > >>>> thursday
> > >>>> > >> afternoon (4PM California time/8AM Beijing time) to get the
> ball
> > >>>> > rolling.
> > >>>> > >> Please come if interested. Zoom details are below.
> > >>>> > >>
> > >>>> > >> Yours,
> > >>>> > >> S
> > >>>> > >> 1.
> > >>>> > >>
> > >>>> >
> > >>>>
> >
> https://docs.google.com/document/d/11ChsSb2LGrSzrSJz8pDCAw5IewmaMV0ZDN1LrMkAj4s/edit#heading=h.hdf0rnyevxz2
> > >>>> > >>
> > >>>> > >>
> > >>>> > >> Topic: hbase split-meta design warmup chat
> > >>>> > >> Time: Mar 25, 2021 04:00 PM Pacific Time (US and Canada)
> > >>>> > >>
> > >>>> > >> Join Zoom Meeting
> > >>>> > >>
> > >>>> >
> > >>>>
> >
> https://us04web.zoom.us/j/75988003798?pwd=Wi9mU0w0T2ZjTFNBaE9lUmtTbHRpQT09
> > >>>> > >>
> > >>>> > >> Meeting ID: 759 8800 3798
> > >>>> > >> Passcode: hbase
> > >>>> > >>
> > >>>> > >>
> > >>>> > >> On Tue, Jan 5, 2021 at 9:13 AM Stack <[email protected]> wrote:
> > >>>> > >>
> > >>>> > >>> FYI, a few of us have been working on the redo/reset of the
> > split
> > >>>> meta
> > >>>> > >>> design (HBASE-25382). We (think we've) finished the
> > requirements.
> > >>>> Are
> > >>>> > there
> > >>>> > >>> any others to consider?
> > >>>> > >>>
> > >>>> > >>> Feedback and contribs welcome. Otherwise, on to the next phase
> > --
> > >>>> > design.
> > >>>> > >>>
> > >>>> > >>> Thanks,
> > >>>> > >>> S
> > >>>> > >>>
> > >>>> > >>
> > >>>> >
> > >>>>
> > >>>
> >
>

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