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