User Guide, prepared by our tech writer Frank Welsh, was attached to HBASE-7912.
-Vlad 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) >> > > >> > >> > >
