Thanks for forking the thread Vinod, SGTM, though I really do recommend waiting for 2.9 given the current size of 2.8. I'm not a fan of an "off by default" half-measure, since it doesn't change our compatibility requirements, and there's some major NN surgery that can't really be disabled.
If we do find a major user who's backported this to their own branch-2 fork, I agree that's motivation to get it in an upstream release quicker. I haven't heard anything along these lines though. On Mon, Nov 2, 2015 at 11:49 AM, Vinod Vavilapalli <vino...@hortonworks.com> wrote: > Forking the thread. Started looking at the 2.8 list, various features’ > status and arrived here. > > While I understand the pervasive nature of EC and a need for a significant > bake-in, moving this to a 3.x release is not a good idea. We will surely > get a 2.8 out this year and, as needed, I can even spend time getting > started on a 2.9. OTOH, 3.x is long ways off, and given all the > incompatibilities there, it would be a while before users can get their > hands on EC if it were to be only on 3.x. At best, this may force sites > that want EC to backport the entire EC feature to older releases, at worst > this will be repeat the mess of 0.20 security release forks. > > If we think adding this to 2.8 (even if it switched off) is too much risk > per our original plan, let’s move this to 2.9, there by leaving enough time > for stability, integration testing and bake-in, and a realistic chance of > having it end up on users’ clusters soonish. > > +Vinod > > > On Oct 19, 2015, at 1:44 PM, Andrew Wang <andrew.w...@cloudera.com> > wrote: > > > > I think our plan thus far has been to target this for 3.0. I'm okay with > > putting it in branch-2 if we've given a hard look at compatibility, but > > I'll note though that 2.8 is already looking like quite a large release, > > and our release bandwidth has been focused on the 2.6 and 2.7 maintenance > > releases. Adding another multi-hundred JIRAs to 2.8 might make it too > > unwieldy to get out the door. If we bump EC past that, 3.0 might very > well > > be our next release vehicle. I do plan to revive the 3.0 schedule some > time > > next year. With EC and JDK8 in a good spot, the only big feature > remaining > > is classpath isolation. > > > > EC is also a pretty fundamental change to HDFS. Even if it's compatible, > in > > terms of size and impact it might best belong in a new major release. > > > > Best, > > Andrew > > > > On Fri, Oct 16, 2015 at 7:04 PM, Vinayakumar B < > > vinayakumarb.apa...@gmail.com> wrote: > > > >> Is anyone else also thinks that feature is ready to goto branch-2 as > well? > >> > >> Its > 2 weeks EC landed on trunk. IMo Looks Its quite stable since then > and > >> ready to go in branch-2. > >> > >> -Vinay > >> On Oct 6, 2015 12:51 AM, "Zhe Zhang" <zhezh...@cloudera.com> wrote: > >> > >>> Thanks Vinay for capturing the issue and Uma for offering the help. > >>> > >>> --- > >>> Zhe Zhang > >>> > >>> On Mon, Oct 5, 2015 at 12:19 PM, Gangumalla, Uma < > >> uma.ganguma...@intel.com > >>>> > >>> wrote: > >>> > >>>> Vinay, > >>>> > >>>> > >>>> I would merge them as part of HDFS-9182. > >>>> > >>>> Thanks, > >>>> Uma > >>>> > >>>> > >>>> > >>>> On 10/5/15, 12:48 AM, "Vinayakumar B" <vinayakum...@apache.org> > wrote: > >>>> > >>>>> Hi Andrew, > >>>>> I see CHANGES.txt entries not yet merged from > >> CHANGES-HDFS-EC-7285.txt. > >>>>> > >>>>> Was this intentional? > >>>>> > >>>>> Regards, > >>>>> Vinay > >>>>> > >>>>> On Wed, Sep 30, 2015 at 9:15 PM, Andrew Wang < > >> andrew.w...@cloudera.com> > >>>>> wrote: > >>>>> > >>>>>> Branch has been merged to trunk, thanks again to everyone who worked > >>> on > >>>>>> the > >>>>>> feature! > >>>>>> > >>>>>> On Tue, Sep 29, 2015 at 10:44 PM, Zhe Zhang <zhezh...@cloudera.com> > >>>>>> wrote: > >>>>>> > >>>>>>> Thanks everyone who has participated in this discussion. > >>>>>>> > >>>>>>> With 7 +1's (5 binding and 2 non-binding), and no -1, this vote > >> has > >>>>>> passed. > >>>>>>> I will do a final 'git merge' with trunk and work with Andrew to > >>> merge > >>>>>> the > >>>>>>> branch to trunk. I'll update on this thread when the merge is > >> done. > >>>>>>> > >>>>>>> --- > >>>>>>> Zhe Zhang > >>>>>>> > >>>>>>> On Thu, Sep 24, 2015 at 11:08 PM, Liu, Yi A <yi.a....@intel.com> > >>>>>> wrote: > >>>>>>> > >>>>>>>> (Change it to binding.) > >>>>>>>> > >>>>>>>> +1 > >>>>>>>> I have been involved in the development and code review on the > >>>>>> feature > >>>>>>>> branch. It's a great feature and I think it's ready to merge it > >>> into > >>>>>>> trunk. > >>>>>>>> > >>>>>>>> Thanks all for the contribution. > >>>>>>>> > >>>>>>>> Regards, > >>>>>>>> Yi Liu > >>>>>>>> > >>>>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: Liu, Yi A > >>>>>>>> Sent: Friday, September 25, 2015 1:51 PM > >>>>>>>> To: hdfs-dev@hadoop.apache.org > >>>>>>>> Subject: RE: [VOTE] Merge HDFS-7285 (erasure coding) branch to > >>> trunk > >>>>>>>> > >>>>>>>> +1 (non-binding) > >>>>>>>> I have been involved in the development and code review on the > >>>>>> feature > >>>>>>>> branch. It's a great feature and I think it's ready to merge it > >>> into > >>>>>>> trunk. > >>>>>>>> > >>>>>>>> Thanks all for the contribution. > >>>>>>>> > >>>>>>>> Regards, > >>>>>>>> Yi Liu > >>>>>>>> > >>>>>>>> > >>>>>>>> -----Original Message----- > >>>>>>>> From: Vinayakumar B [mailto:vinayakum...@apache.org] > >>>>>>>> Sent: Friday, September 25, 2015 12:21 PM > >>>>>>>> To: hdfs-dev@hadoop.apache.org > >>>>>>>> Subject: Re: [VOTE] Merge HDFS-7285 (erasure coding) branch to > >>> trunk > >>>>>>>> > >>>>>>>> +1, > >>>>>>>> > >>>>>>>> I've been involved starting from design and development of > >>>>>> ErasureCoding. > >>>>>>>> I think phase 1 of this development is ready to be merged to > >>> trunk. > >>>>>>>> It had come a long way to the current state with significant > >>> effort > >>>>>> of > >>>>>>>> many Contributors and Reviewers for both design and code. > >>>>>>>> > >>>>>>>> Thanks Everyone for the efforts. > >>>>>>>> > >>>>>>>> Regards, > >>>>>>>> Vinay > >>>>>>>> > >>>>>>>> On Wed, Sep 23, 2015 at 10:53 PM, Jing Zhao <ji...@apache.org> > >>>>>> wrote: > >>>>>>>> > >>>>>>>>> +1 > >>>>>>>>> > >>>>>>>>> I've been involved in both development and review on the > >> branch, > >>>>>> and > >>>>>> I > >>>>>>>>> believe it's now ready to get merged into trunk. Many thanks > >> to > >>>>>> all > >>>>>>>>> the contributors and reviewers! > >>>>>>>>> > >>>>>>>>> Thanks, > >>>>>>>>> -Jing > >>>>>>>>> > >>>>>>>>> On Tue, Sep 22, 2015 at 6:17 PM, Zheng, Kai < > >>> kai.zh...@intel.com> > >>>>>>> wrote: > >>>>>>>>> > >>>>>>>>>> Non-binding +1 > >>>>>>>>>> > >>>>>>>>>> According to our extensive performance tests, striping + > >> ISA-L > >>>>>> coder > >>>>>>>>> based > >>>>>>>>>> erasure coding not only can save storage, but also can > >>> increase > >>>>>> the > >>>>>>>>>> throughput of a client or a cluster. It will be a great > >>>>>> addition to > >>>>>>>>>> HDFS and its users. Based on the latest branch codes, we > >> also > >>>>>>>>>> observed it's > >>>>>>>>> very > >>>>>>>>>> reliable in the concurrent tests. We'll provide the perf > >> test > >>>>>> report > >>>>>>>>> after > >>>>>>>>>> it's sorted out and hope it helps. > >>>>>>>>>> Thanks! > >>>>>>>>>> > >>>>>>>>>> Regards, > >>>>>>>>>> Kai > >>>>>>>>>> > >>>>>>>>>> -----Original Message----- > >>>>>>>>>> From: Gangumalla, Uma [mailto:uma.ganguma...@intel.com] > >>>>>>>>>> Sent: Wednesday, September 23, 2015 8:50 AM > >>>>>>>>>> To: hdfs-dev@hadoop.apache.org; > >> common-...@hadoop.apache.org > >>>>>>>>>> Subject: Re: [VOTE] Merge HDFS-7285 (erasure coding) branch > >> to > >>>>>> trunk > >>>>>>>>>> > >>>>>>>>>> +1 > >>>>>>>>>> > >>>>>>>>>> Great addition to HDFS. Thanks all contributors for the nice > >>>>>> work. > >>>>>>>>>> > >>>>>>>>>> Regards, > >>>>>>>>>> Uma > >>>>>>>>>> > >>>>>>>>>> On 9/22/15, 3:40 PM, "Zhe Zhang" <zhezh...@cloudera.com> > >>> wrote: > >>>>>>>>>> > >>>>>>>>>>> Hi, > >>>>>>>>>>> > >>>>>>>>>>> I'd like to propose a vote to merge the HDFS-7285 feature > >>>>>> branch > >>>>>>>>>>> back to trunk. Since November 2014 we have been designing > >> and > >>>>>>>>>>> developing this feature under the umbrella JIRAs HDFS-7285 > >>> and > >>>>>>>>>>> HADOOP-11264, and have committed approximately 210 patches. > >>>>>>>>>>> > >>>>>>>>>>> The HDFS-7285 feature branch was created to support the > >> first > >>>>>> phase > >>>>>>>>>>> of HDFS erasure coding (HDFS-EC). The objective of HDFS-EC > >> is > >>>>>> to > >>>>>>>>>>> significantly reduce storage space usage in HDFS clusters. > >>>>>> Instead > >>>>>>>>>>> of always creating 3 replicas of each block with 200% > >> storage > >>>>>> space > >>>>>>>>>>> overhead, HDFS-EC provides data durability through parity > >>> data > >>>>>>> blocks. > >>>>>>>>>>> With most EC configurations, the storage overhead is no > >> more > >>>>>> than > >>>>>>> 50%. > >>>>>>>>>>> Based on profiling results of production clusters, we > >> decided > >>>>>> to > >>>>>>>>>>> support EC with the striped block layout in the first > >> phase, > >>> so > >>>>>>>>>>> that small files can be better handled. This means dividing > >>>>>> each > >>>>>>>>>>> logical HDFS file block into smaller units (striping cells) > >>> and > >>>>>>>>>>> spreading them on a set of DataNodes in round-robin > >> fashion. > >>>>>> Parity > >>>>>>>>>>> cells are generated for each stripe of original data cells. > >>> We > >>>>>> have > >>>>>>>>>>> made changes to NameNode, client, and DataNode to > >> generalize > >>>>>> the > >>>>>>>>>>> block concept and handle the mapping between a logical file > >>>>>> block > >>>>>>>>>>> and its internal storage blocks. For further details please > >>> see > >>>>>> the > >>>>>>>>>>> design doc on HDFS-7285. > >>>>>>>>>>> HADOOP-11264 focuses on providing flexible and > >>> high-performance > >>>>>>>>>>> codec calculation support. > >>>>>>>>>>> > >>>>>>>>>>> The nightly Jenkins job of the branch has reported several > >>>>>>>>>>> successful runs, and doesn't show new flaky tests compared > >>> with > >>>>>>>>>>> trunk. We have posted several versions of the test plan > >>>>>> including > >>>>>>>>>>> both unit testing and cluster testing, and have executed > >> most > >>>>>> tests > >>>>>>>>>>> in the plan. The most basic functionalities have been > >>>>>> extensively > >>>>>>>>>>> tested and verified in several real clusters with different > >>>>>>>>>>> hardware configurations; results have been very stable. We > >>> have > >>>>>>>>>>> created follow-on tasks for more advanced error handling > >> and > >>>>>>>> optimization under the umbrella HDFS-8031. > >>>>>>>>>>> We also plan to implement or harden the integration of EC > >>> with > >>>>>>>>>>> existing features such as WebHDFS, snapshot, append, > >>> truncate, > >>>>>>>>>>> hflush, hsync, and so forth. > >>>>>>>>>>> > >>>>>>>>>>> Development of this feature has been a collaboration across > >>>>>> many > >>>>>>>>>>> companies and institutions. I'd like to thank J. Andreina, > >>>>>> Takanobu > >>>>>>>>>>> Asanuma, Vinayakumar B, Li Bo, Takuya Fukudome, Uma > >> Maheswara > >>>>>> Rao > >>>>>>>>>>> G, Rui Li, Yi Liu, Colin McCabe, Xinwei Qin, Rakesh R, Gao > >>> Rui, > >>>>>> Kai > >>>>>>>>>>> Sasaki, Walter Su, Tsz Wo Nicholas Sze, Andrew Wang, Yong > >>>>>> Zhang, > >>>>>>>>>>> Jing Zhao, Hui Zheng and Kai Zheng for their code > >>> contributions > >>>>>> and > >>>>>>>> reviews. > >>>>>>>>>>> Andrew and Kai Zheng also made fundamental contributions to > >>> the > >>>>>>>>>>> initial design. Rui Li, Gao Rui, Kai Sasaki, Kai Zheng and > >>> many > >>>>>>>>>>> other contributors have made great efforts in system > >> testing. > >>>>>> Many > >>>>>>>>>>> thanks go to Weihua Jiang for proposing the JIRA, and ATM, > >>> Todd > >>>>>>>>>>> Lipcon, Silvius Rus, Suresh, as well as many others for > >>>>>> providing > >>>>>>>> helpful feedbacks. > >>>>>>>>>>> > >>>>>>>>>>> Following the community convention, this vote will last > >> for 7 > >>>>>> days > >>>>>>>>>>> (ending September 29th). Votes from Hadoop committers are > >>>>>> binding > >>>>>>>>>>> but non-binding votes are very welcome as well. And here's > >> my > >>>>>>>>>>> non-binding > >>>>>>>>> +1. > >>>>>>>>>>> > >>>>>>>>>>> Thanks, > >>>>>>>>>>> --- > >>>>>>>>>>> Zhe Zhang > >>>>>>>>>> > >>>>>>>>>> > >>>>>>>>> > >>>>>>>> > >>>>>>> > >>>>>> > >>>> > >>>> > >>> > >> > >
