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 > >>>> > >>> > >>>> > >> > >>>> > > >>>> > >>> >
