Mega patch (rev 18) is on HBASE-14123. Please comment on HBASE-14123 on how you want to review.
Thanks On Mon, Sep 12, 2016 at 12:15 PM, Stack <st...@duboce.net> wrote: > On review of the 'patch', do I just compare the branch to master or is > there a megapatch posted somewhere (I think I saw one but it seemed stale > and then I 'lost' the tab). Sorry for dumb question. > St.Ack > > On Mon, Sep 12, 2016 at 12:01 PM, Stack <st...@duboce.net> wrote: > > > Late to the game. A few comments after rereading this thread as a 'user'. > > > > + Before merge, a user-facing feature like this should work (If this is > "higher-bar > > for new features", bring it on -- smile). > > + As a user, I tried the branch with tools after reviewing the > just-posted > > doc. I had an 'interesting' experience (left comments up on issue). I > think > > the tooling/doc. important to get right. If it breaks easily or is > > inconsistent (or lacks 'polish'), operators will judge the whole > > backup/restore tooling chain as not trustworthy and abandon it. Lets not > > have this happen to this feature. > > + Matteo's suggestion (with a helpful starter list) that there needs to > be > > explicit qualification on what is actually being delivered -- including a > > listing of limitations (some look serious such as data bleed from other > > regions in WALs, but maybe I don't care for my use case...) -- needs to > > accompany the merge. Lets fold them into the user doc. in the technical > > overview area as suggested so user expectations are properly managed > > (otherwise, they expect the world and will just give up when we fall > > short). Vladimir did a list of what is in each of the phases above which > > would serve as a good start. > > + Is this feature 'experimental' (Matteo asks above). I'd prefer it is > > not. If it is, it should be labelled all over that it is so. I see > current > > state called out as a '... technical preview feature'. Does this mean > > not-for-users? > > > > St.Ack > > > > > > > > > > > > > > > > > > > > > > > > On Mon, Sep 12, 2016 at 8:03 AM, Ted Yu <yuzhih...@gmail.com> wrote: > > > >> Sean: > >> Do you have more comments ? > >> > >> Cheers > >> > >> On Fri, Sep 9, 2016 at 1:42 PM, Vladimir Rodionov < > vladrodio...@gmail.com > >> > > >> wrote: > >> > >> > Sean, > >> > > >> > Backup/Restore can fail due to various reasons: network outage > (cluster > >> > wide), various time-outs in HBase and HDFS layer, M/R failure due to > >> "HDFS > >> > exceeded quota", user error (manual deletion of data) and so on so on. > >> That > >> > is impossible to enumerate all possible types of failures in a > >> distributed > >> > system - that is not our goal/task. > >> > > >> > We focus completely on backup system table consistency in a presence > of > >> any > >> > type of failure. That is what I call "tolerance to failures". > >> > > >> > On a failure: > >> > > >> > BACKUP. All backup system information (prior to backup) will be > restored > >> > and all temporary data, related to a failed session, in HDFS will be > >> > deleted > >> > RESTORE. We do not care about system data, because restore does not > >> change > >> > it. Temporary data in HDFS will be cleaned up and table will be in a > >> state > >> > back to where it was before operation started. > >> > > >> > This is what user should expect in case of a failure. > >> > > >> > -Vlad > >> > > >> > > >> > -Vlad > >> > > >> > On Fri, Sep 9, 2016 at 12:56 PM, Sean Busbey <bus...@apache.org> > wrote: > >> > > >> > > Failing in a consistent way, with docs that explain the various > >> > > expected failures would be sufficient. > >> > > > >> > > On Fri, Sep 9, 2016 at 12:16 PM, Vladimir Rodionov > >> > > <vladrodio...@gmail.com> wrote: > >> > > > Do not worry Sean, doc is coming today as a preview and our writer > >> > Frank > >> > > > will be working on a putting it into Apache repo. Timeline > depends > >> on > >> > > > Franks schedule but I hope we will get it rather sooner than > later. > >> > > > > >> > > > As for failure testing, we are focusing only on a consistent state > >> of > >> > > > backup system data in a presence of any type of failures, We are > not > >> > > going > >> > > > to implement anything more "fancy", than that. We allow both: > >> backup > >> > and > >> > > > restore to fail. What we do not allow is to have system data > >> corrupted. > >> > > > Will it suffice for you? Do you have any other concerns, you want > >> us to > >> > > > address? > >> > > > > >> > > > -Vlad > >> > > > > >> > > > > >> > > > On Fri, Sep 9, 2016 at 10:56 AM, Sean Busbey <bus...@apache.org> > >> > wrote: > >> > > > > >> > > >> "docs will come to Apache soon" does not address my concern > around > >> > docs > >> > > at > >> > > >> all, unless said docs have already made it into the project > repo. I > >> > > don't > >> > > >> want third party resources for using a major and important > feature > >> of > >> > > the > >> > > >> project, I want us to provide end users with what they need to > get > >> the > >> > > job > >> > > >> done. > >> > > >> > >> > > >> I see some calls for patience on the failure testing, but the > >> appeal > >> > to > >> > > us > >> > > >> having done a bad job of requiring proper tests of previous > >> features > >> > > just > >> > > >> makes me more concerned about not getting them here. I don't want > >> to > >> > set > >> > > >> yet another bad example that will then be pointed to in the > future. > >> > > >> > >> > > >> On Sep 8, 2016 10:50, "Ted Yu" <yuzhih...@gmail.com> wrote: > >> > > >> > >> > > >> > Is there any concern which is not addressed ? > >> > > >> > > >> > > >> > Do we need another Vote thread ? > >> > > >> > > >> > > >> > Thanks > >> > > >> > > >> > > >> > On Thu, Sep 8, 2016 at 9:21 AM, Andrew Purtell < > >> apurt...@apache.org > >> > > > >> > > >> > wrote: > >> > > >> > > >> > > >> > > Vlad, > >> > > >> > > > >> > > >> > > I apologize for using the term 'half-baked' in a way that > could > >> > > seem a > >> > > >> > > description of HBASE-7912. I meant that as a general > >> hypothetical. > >> > > >> > > > >> > > >> > > On Wed, Sep 7, 2016 at 9:36 AM, Vladimir Rodionov < > >> > > >> > vladrodio...@gmail.com> > >> > > >> > > wrote: > >> > > >> > > > >> > > >> > > > >> I'm not sure that "There is already lots of half-baked > >> code > >> > in > >> > > the > >> > > >> > > > branch, > >> > > >> > > > so what's the harm in adding more?" > >> > > >> > > > > >> > > >> > > > I meant - not production - ready yet. This is 2.0 > development > >> > > branch > >> > > >> > and, > >> > > >> > > > hence many features are in works, > >> > > >> > > > not being tested well etc. I do not consider backup as half > >> > baked > >> > > >> > > feature - > >> > > >> > > > it has passed our internal QA and has very good doc, which > we > >> > will > >> > > >> > > provide > >> > > >> > > > to Apache shortly. > >> > > >> > > > > >> > > >> > > > -Vlad > >> > > >> > > > > >> > > >> > > > On Wed, Sep 7, 2016 at 9:13 AM, Andrew Purtell < > >> > > apurt...@apache.org> > >> > > >> > > > wrote: > >> > > >> > > > > >> > > >> > > > > We shouldn't admit half baked changes that won't be > >> finished. > >> > > >> However > >> > > >> > > in > >> > > >> > > > > this case the crew working on this feature are long > timers > >> and > >> > > less > >> > > >> > > > likely > >> > > >> > > > > than just about anyone to leave something in a half baked > >> > > state. Of > >> > > >> > > > course > >> > > >> > > > > there is no guarantee how anything will turn out, but I > am > >> > > willing > >> > > >> to > >> > > >> > > > take > >> > > >> > > > > a little on faith if they feel their best path forward > now > >> is > >> > to > >> > > >> > merge > >> > > >> > > to > >> > > >> > > > > trunk. I only wish I had bandwidth to have done some real > >> > > kicking > >> > > >> of > >> > > >> > > the > >> > > >> > > > > tires by now. Maybe this week. > >> > > >> > > > > > >> > > >> > > > > (Yes, I'm using some of that time for this email :-) but > I > >> > type > >> > > >> > fast.) > >> > > >> > > > > > >> > > >> > > > > That said, I would like to agitate for making 2.0 more > real > >> > and > >> > > >> spend > >> > > >> > > > some > >> > > >> > > > > time on it now that I'm winding down with 0.98. I think > >> that > >> > > means > >> > > >> > > > > branching for 2.0 real soon now and even evicting things > >> from > >> > > 2.0 > >> > > >> > > branch > >> > > >> > > > > that aren't finished or stable, leaving them only once > >> again > >> > in > >> > > the > >> > > >> > > > master > >> > > >> > > > > branch. Or, maybe just evicting them. Let's take it case > by > >> > > case. > >> > > >> > > > > > >> > > >> > > > > I think this feature can come in relatively safely. As > >> added > >> > > >> > insurance, > >> > > >> > > > > let's admit the possibility it could be reverted on the > 2.0 > >> > > branch > >> > > >> if > >> > > >> > > > folks > >> > > >> > > > > working on stabilizing 2.0 decide to evict it because it > is > >> > > >> > unfinished > >> > > >> > > or > >> > > >> > > > > unstable, because that certainly can happen. I would > >> expect if > >> > > talk > >> > > >> > > like > >> > > >> > > > > that starts, we'd get help finishing or stabilizing > what's > >> > under > >> > > >> > > > discussion > >> > > >> > > > > for revert. Or, we'd have a revert. Either way the > outcome > >> is > >> > > >> > > acceptable. > >> > > >> > > > > > >> > > >> > > > > > >> > > >> > > > > On Wed, Sep 7, 2016 at 8:56 AM, Dima Spivak < > >> > > dimaspi...@apache.org > >> > > >> > > >> > > >> > > > wrote: > >> > > >> > > > > > >> > > >> > > > > > I'm not sure that "There is already lots of half-baked > >> code > >> > in > >> > > >> the > >> > > >> > > > > branch, > >> > > >> > > > > > so what's the harm in adding more?" is a good code > commit > >> > > >> > philosophy > >> > > >> > > > for > >> > > >> > > > > a > >> > > >> > > > > > fault-tolerant distributed data store. ;) > >> > > >> > > > > > > >> > > >> > > > > > More seriously, a lack of test coverage for existing > >> > features > >> > > >> > > shouldn't > >> > > >> > > > > be > >> > > >> > > > > > used as justification for introducing new features with > >> the > >> > > same > >> > > >> > > > > > shortcomings. Ultimately, it's the end user who will > feel > >> > the > >> > > >> pain, > >> > > >> > > so > >> > > >> > > > > > shouldn't we do everything we can to mitigate that? > >> > > >> > > > > > > >> > > >> > > > > > -Dima > >> > > >> > > > > > > >> > > >> > > > > > On Wed, Sep 7, 2016 at 8:46 AM, Vladimir Rodionov < > >> > > >> > > > > vladrodio...@gmail.com> > >> > > >> > > > > > wrote: > >> > > >> > > > > > > >> > > >> > > > > > > Sean, > >> > > >> > > > > > > > >> > > >> > > > > > > * have docs > >> > > >> > > > > > > > >> > > >> > > > > > > Agree. We have a doc and backup is the most > documented > >> > > feature > >> > > >> > :), > >> > > >> > > we > >> > > >> > > > > > will > >> > > >> > > > > > > release it shortly to Apache. > >> > > >> > > > > > > > >> > > >> > > > > > > * have sunny-day correctness tests > >> > > >> > > > > > > > >> > > >> > > > > > > Feature has close to 60 test cases, which run for > >> approx > >> > 30 > >> > > >> min. > >> > > >> > > We > >> > > >> > > > > can > >> > > >> > > > > > > add more, if community do not mind :) > >> > > >> > > > > > > > >> > > >> > > > > > > * have correctness-in-face-of-failure tests > >> > > >> > > > > > > > >> > > >> > > > > > > Any examples of these tests in existing features? In > >> > works, > >> > > we > >> > > >> > > have a > >> > > >> > > > > > clear > >> > > >> > > > > > > understanding of what should be done by the time of > 2.0 > >> > > >> release. > >> > > >> > > > > > > That is very close goal for us, to verify IT monkey > for > >> > > >> existing > >> > > >> > > > code. > >> > > >> > > > > > > > >> > > >> > > > > > > * don't rely on things outside of HBase for normal > >> > operation > >> > > >> > (okay > >> > > >> > > > for > >> > > >> > > > > > > advanced operation) > >> > > >> > > > > > > > >> > > >> > > > > > > We do not. > >> > > >> > > > > > > > >> > > >> > > > > > > Enormous time has been spent already on the > development > >> > and > >> > > >> > testing > >> > > >> > > > the > >> > > >> > > > > > > feature, it has passed our internal tests and many > >> rounds > >> > of > >> > > >> code > >> > > >> > > > > reviews > >> > > >> > > > > > > by HBase committers. We do not mind if someone from > >> HBase > >> > > >> > community > >> > > >> > > > > > > (outside of HW) will review the code, but it will > >> probably > >> > > >> takes > >> > > >> > > > > forever > >> > > >> > > > > > to > >> > > >> > > > > > > wait for volunteer?, the feature is quite large (1MB+ > >> > > >> cumulative > >> > > >> > > > patch) > >> > > >> > > > > > > > >> > > >> > > > > > > 2.0 branch is full of half baked features, most of > them > >> > are > >> > > in > >> > > >> > > active > >> > > >> > > > > > > development, therefore I am not following you here, > >> Sean? > >> > > Why > >> > > >> > > > > HBASE-7912 > >> > > >> > > > > > is > >> > > >> > > > > > > not good enough yet to be integrated into 2.0 branch? > >> > > >> > > > > > > > >> > > >> > > > > > > -Vlad > >> > > >> > > > > > > > >> > > >> > > > > > > > >> > > >> > > > > > > > >> > > >> > > > > > > > >> > > >> > > > > > > > >> > > >> > > > > > > On Wed, Sep 7, 2016 at 8:23 AM, Sean Busbey < > >> > > bus...@apache.org > >> > > >> > > >> > > >> > > > wrote: > >> > > >> > > > > > > > >> > > >> > > > > > > > On Tue, Sep 6, 2016 at 10:36 PM, Josh Elser < > >> > > >> > > josh.el...@gmail.com> > >> > > >> > > > > > > wrote: > >> > > >> > > > > > > > > So, the answer to Sean's original question is "as > >> > > robust as > >> > > >> > > > > snapshots > >> > > >> > > > > > > > > presently are"? (independence of backup/restore > >> > failure > >> > > >> > > tolerance > >> > > >> > > > > > from > >> > > >> > > > > > > > > snapshot failure tolerance) > >> > > >> > > > > > > > > > >> > > >> > > > > > > > > Is this just a question WRT context of the > change, > >> or > >> > > is it > >> > > >> > > means > >> > > >> > > > > > for a > >> > > >> > > > > > > > veto > >> > > >> > > > > > > > > from you, Sean? Just trying to make sure I'm > >> following > >> > > >> along > >> > > >> > > > > > > adequately. > >> > > >> > > > > > > > > > >> > > >> > > > > > > > > > >> > > >> > > > > > > > > >> > > >> > > > > > > > I'd say ATM I'm -0, bordering on -1 but not for > >> reasons > >> > I > >> > > can > >> > > >> > > > > > articulate > >> > > >> > > > > > > > well. > >> > > >> > > > > > > > > >> > > >> > > > > > > > Here's an attempt. > >> > > >> > > > > > > > > >> > > >> > > > > > > > We've been trying to move, as a community, towards > >> > > minimizing > >> > > >> > > risk > >> > > >> > > > to > >> > > >> > > > > > > > downstream folks by getting "complete enough for > use" > >> > > gates > >> > > >> in > >> > > >> > > > place > >> > > >> > > > > > > > before we introduce new features. This was spurred > >> by a > >> > > some > >> > > >> > > > features > >> > > >> > > > > > > > getting in half-baked and never making it to "can > >> really > >> > > use" > >> > > >> > > > status > >> > > >> > > > > > > > (I'm thinking of distributed log replay and the > >> zk-less > >> > > >> > > assignment > >> > > >> > > > > > > > stuff, I don't recall if there was more). > >> > > >> > > > > > > > > >> > > >> > > > > > > > The gates, generally, included things like: > >> > > >> > > > > > > > > >> > > >> > > > > > > > * have docs > >> > > >> > > > > > > > * have sunny-day correctness tests > >> > > >> > > > > > > > * have correctness-in-face-of-failure tests > >> > > >> > > > > > > > * don't rely on things outside of HBase for normal > >> > > operation > >> > > >> > > (okay > >> > > >> > > > > for > >> > > >> > > > > > > > advanced operation) > >> > > >> > > > > > > > > >> > > >> > > > > > > > As an example, we kept the MOB work off in a branch > >> and > >> > > out > >> > > >> of > >> > > >> > > > master > >> > > >> > > > > > > > until it could pass these criteria. The big > exemption > >> > > we've > >> > > >> had > >> > > >> > > to > >> > > >> > > > > > > > this was the hbase-spark integration, where we all > >> > agreed > >> > > it > >> > > >> > > could > >> > > >> > > > > > > > land in master because it was very well isolated > (the > >> > > slide > >> > > >> > away > >> > > >> > > > from > >> > > >> > > > > > > > including docs as a first-class part of building up > >> that > >> > > >> > > > integration > >> > > >> > > > > > > > has led me to doubt the wisdom of this decision). > >> > > >> > > > > > > > > >> > > >> > > > > > > > We've also been treating inclusion in a "probably > >> will > >> > be > >> > > >> > > released > >> > > >> > > > to > >> > > >> > > > > > > > downstream" branches as a higher bar, requiring > >> > > >> > > > > > > > > >> > > >> > > > > > > > * don't moderately impact performance when the > >> feature > >> > > isn't > >> > > >> in > >> > > >> > > use > >> > > >> > > > > > > > * don't severely impact performance when the > feature > >> is > >> > in > >> > > >> use > >> > > >> > > > > > > > * either default-to-on or show enough demand to > >> believe > >> > a > >> > > >> > > > non-trivial > >> > > >> > > > > > > > number of folks will turn the feature on > >> > > >> > > > > > > > > >> > > >> > > > > > > > The above has kept MOB and hbase-spark integration > >> out > >> > of > >> > > >> > > branch-1, > >> > > >> > > > > > > > presumably while they've "gotten more stable" in > >> master > >> > > from > >> > > >> > the > >> > > >> > > > odd > >> > > >> > > > > > > > vendor inclusion. > >> > > >> > > > > > > > > >> > > >> > > > > > > > Are we going to have a 2.0 release before the end > of > >> the > >> > > >> year? > >> > > >> > > > We're > >> > > >> > > > > > > > coming up on 1.5 years since the release of version > >> 1.0; > >> > > >> seems > >> > > >> > > like > >> > > >> > > > > > > > it's about time, though I haven't seen any concrete > >> > plans > >> > > >> this > >> > > >> > > > year. > >> > > >> > > > > > > > Presuming we are going to have one by the end of > the > >> > > year, it > >> > > >> > > > seems a > >> > > >> > > > > > > > bit close to still be adding in "features that need > >> > > maturing" > >> > > >> > on > >> > > >> > > > the > >> > > >> > > > > > > > branch. > >> > > >> > > > > > > > > >> > > >> > > > > > > > The lack of a concrete plan for 2.0 keeps me from > >> > > considering > >> > > >> > > these > >> > > >> > > > > > > > things blocker at the moment. But I know first hand > >> how > >> > > much > >> > > >> > > > trouble > >> > > >> > > > > > > > folks have had with other features that have gone > >> into > >> > > >> > downstream > >> > > >> > > > > > > > facing releases without robustness checks (i.e. > >> > > replication), > >> > > >> > and > >> > > >> > > > I'm > >> > > >> > > > > > > > concerned about what we're setting up if 2.0 goes > out > >> > with > >> > > >> this > >> > > >> > > > > > > > feature in its current state. > >> > > >> > > > > > > > > >> > > >> > > > > > > > >> > > >> > > > > > > >> > > >> > > > > > >> > > >> > > > > > >> > > >> > > > > > >> > > >> > > > > -- > >> > > >> > > > > Best regards, > >> > > >> > > > > > >> > > >> > > > > - Andy > >> > > >> > > > > > >> > > >> > > > > Problems worthy of attack prove their worth by hitting > >> back. - > >> > > Piet > >> > > >> > > Hein > >> > > >> > > > > (via Tom White) > >> > > >> > > > > > >> > > >> > > > > >> > > >> > > > >> > > >> > > > >> > > >> > > > >> > > >> > > -- > >> > > >> > > Best regards, > >> > > >> > > > >> > > >> > > - Andy > >> > > >> > > > >> > > >> > > Problems worthy of attack prove their worth by hitting back. > - > >> > Piet > >> > > >> Hein > >> > > >> > > (via Tom White) > >> > > >> > > > >> > > >> > > >> > > >> > >> > > > >> > > >> > > > > >
