It's simple: Use a tool (something derived from Tool, like our other utilities for import, export, etc.), or use a separate process, but don't "shell out" to MR from the Master.
On Fri, Sep 23, 2016 at 12:24 PM, Vladimir Rodionov <vladrodio...@gmail.com> wrote: > >> -1 on that backup be in core hbase > > Not sure I understand what it means. > > 1. We are not allowed to use Master to orchestrate the whole process? We > have already brought up all advantages of using > Master and distributed procedures for backup and restore. > > > Downside of moving this to client tool is lack of fault tolerance: > 1.1 Client won't be allowed to do any operations, that can, potentially > affect > cluster, such as disabling splits/merges, balancer. > 1.2 In case of client failure who will be doing the whole rollback stuff? > We are trying to make it atomic. > > Security is not clear. > > 2. We are not allowed to modify code of existing HBase core classes (what > does core mean anyway)? > > 3. We are not allowed to create backup system table (hbase:backup) in a > system space? Only in user space? The table is global. > > 2. is critical. Despite the fact, that 95% of code is new, we have touched, > of course some existing HBase code. > 3. is not that critical, of course we can move backup system into user > space. > > And finally, will moving backup into external tool give us +1 from stack? > > -Vlad > > > > > > On Fri, Sep 23, 2016 at 11:26 AM, Stack <st...@duboce.net> wrote: > > > On Fri, Sep 23, 2016 at 11:22 AM, Vladimir Rodionov < > > vladrodio...@gmail.com> > > wrote: > > > > > >> + MR is dead > > > > > > Does MR know that? :) > > > > > > Again. With all due respect, stack - still no suggestions what should > we > > > use for "bulk data move and transformation" instead of MR? > > > > > > > Use whatever distributed engine suits your fancy -- MR, Spark, > distributed > > shell -- just don't have HBase core depend on it, even optionally. > > > > > > > I suggest voting first on "do we need backup in HBase"? In my opinion, > > some > > > group members still not sure about that and some will give -1 > > > in any case. Just because ... > > > > > > > > We could run a vote, sure. -1 on that backup be in core hbase (+1 on > adding > > all the API any such external tool might need to run). > > > > St.Ack > > > > > > > > > -Vlad > > > > > > > > > > > > > > > > > > > > > On Fri, Sep 23, 2016 at 10:57 AM, Stack <st...@duboce.net> wrote: > > > > > > > On Fri, Sep 23, 2016 at 6:46 AM, Matteo Bertozzi < > > > theo.berto...@gmail.com> > > > > wrote: > > > > > > > > > let me try to go back to my original topic. > > > > > this question was meant to be generic, and provide some rule for > > future > > > > > code. > > > > > > > > > > from what I can gather, a rule that may satisfy everyone can be: > > > > > - we don't want any core feature (e.g. compaction/log-split/log- > > > reply) > > > > > over MR, because some cluster may not want or may have an > > > > > external/uncontrolled MR setup. > > > > > > > > > > > > > +1 > > > > > > > > > > > > > - we allow non-core features (e.g. features enabled by a flag) to > > run > > > MR > > > > > jobs from hbase, because unless you use the feature, MR is not > > > required. > > > > > > > > > > > > > > -1 to hbase core depending on MR or core -- whether behind a flag or > > not > > > -- > > > > ever being able to launch MR jobs. > > > > > > > > + MR is dead. We should be busy working hard to undo it from > > hbase-server > > > > moving it out to be an optional module (Spark would be its peer). > > > > + Master is a rats nest of state. Matteo, Stephen, and Appy are busy > > > > working hard on moving it up on to a new foundation. Lets not clutter > > > task > > > > harder by piling on more moving parts. > > > > > > > > St.Ack > > > > > > > > > > > > > Matteo > > > > > > > > > > > > > > > On Fri, Sep 23, 2016 at 5:39 AM, Ted Yu <yuzhih...@gmail.com> > wrote: > > > > > > > > > > > I suggest you look at Matteo's work for AssignmentManager which > is > > to > > > > > make > > > > > > Master more stable. > > > > > > > > > > > > Cheers > > > > > > > > > > > > On Fri, Sep 23, 2016 at 5:32 AM, 张铎 <palomino...@gmail.com> > wrote: > > > > > > > > > > > > > No, not your fault, at lease, not this time:) > > > > > > > > > > > > > > Why I call the code ugly? Can you simply tell me the sequence > of > > > > calls > > > > > > when > > > > > > > starting up the HMaster? HMaster is also a regionserver so it > > > extends > > > > > > > HRegionServer, and the initialization of HRegionServer > sometimes > > > > needs > > > > > to > > > > > > > make rpc calls to HMaster. A simple change would cause > > > probabilistic > > > > > dead > > > > > > > lock or some strange NPEs... > > > > > > > > > > > > > > That's why I'm very nervous when somebody wants to add new > > features > > > > or > > > > > > add > > > > > > > external dependencies to HMaster, especially add more works for > > the > > > > > start > > > > > > > up processing... > > > > > > > > > > > > > > Thanks. > > > > > > > > > > > > > > 2016-09-23 20:02 GMT+08:00 Ted Yu <yuzhih...@gmail.com>: > > > > > > > > > > > > > > > I read through HADOOP-13433 > > > > > > > > <https://issues.apache.org/jira/browse/HADOOP-13433> - the > > cited > > > > > race > > > > > > > > condition is in jdk. > > > > > > > > > > > > > > > > Suggest pinging the reviewer on JIRA to get it moving. > > > > > > > > > > > > > > > > bq. But the ugly code in HMaster is readlly a problem... > > > > > > > > > > > > > > > > Can you be specific as to which code is ugly ? Is it in the > > > backup > > > > / > > > > > > > > restore mega patch ? > > > > > > > > > > > > > > > > Cheers > > > > > > > > > > > > > > > > On Thu, Sep 22, 2016 at 10:44 PM, 张铎 <palomino...@gmail.com> > > > > wrote: > > > > > > > > > > > > > > > > > If you guys have already implemented the feature in the MR > > way > > > > and > > > > > > the > > > > > > > > > patch is ready for landing on master, I'm a -0 on it as I > do > > > not > > > > > want > > > > > > > to > > > > > > > > > block the development progress. > > > > > > > > > > > > > > > > > > But I strongly suggest later we need to revisit the design > > and > > > > see > > > > > if > > > > > > > we > > > > > > > > > can seperated the logic from HMaster as much as possible. > HA > > is > > > > > not a > > > > > > > big > > > > > > > > > problem if you do not store any metada locally. But the > ugly > > > code > > > > > in > > > > > > > > > HMaster is readlly a problem... > > > > > > > > > > > > > > > > > > And for security, I have a issue pending for a long time. > Can > > > > > someone > > > > > > > > help > > > > > > > > > taking a simple look at it? This is what I mean, ugly > code... > > > > > logout > > > > > > > and > > > > > > > > > destroy the credentials in a subject when it is still being > > > used, > > > > > and > > > > > > > > > declared as LimitPrivacy so I can not change the behivor > and > > > the > > > > > only > > > > > > > way > > > > > > > > > to fix it is to write another piece of ugly code... > > > > > > > > > > > > > > > > > > https://issues.apache.org/jira/browse/HADOOP-13433 > > > > > > > > > > > > > > > > > > 2016-09-23 12:53 GMT+08:00 Vladimir Rodionov < > > > > > vladrodio...@gmail.com > > > > > > >: > > > > > > > > > > > > > > > > > > > >> If in the future, we find better ways of doing this > > > without > > > > > > using > > > > > > > > MR, > > > > > > > > > we > > > > > > > > > > can certainly consider that > > > > > > > > > > > > > > > > > > > > Our framework for distributed operations is abstract and > > > allows > > > > > > > > > > different implementations. MR is just one implementation > we > > > > > > provide. > > > > > > > > > > > > > > > > > > > > -Vlad > > > > > > > > > > > > > > > > > > > > On Thu, Sep 22, 2016 at 9:38 PM, Devaraj Das < > > > > > d...@hortonworks.com > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > Guys, first off apologies for bringing in the topic of > > > > MR-based > > > > > > > > > > > compactions.. But I was thinking more about the > > > SpliceMachine > > > > > > > > approach > > > > > > > > > of > > > > > > > > > > > managing compactions in Spark where apparently they > saw a > > > lot > > > > > of > > > > > > > > > > benefits. > > > > > > > > > > > Apologies for giving you that sore throat Andrew; I > > really > > > > > didn't > > > > > > > > mean > > > > > > > > > to > > > > > > > > > > > :-) > > > > > > > > > > > > > > > > > > > > > > So on this issue, we have these on the plate: > > > > > > > > > > > 0. Somehow not use MR but something like that > > > > > > > > > > > 1. Run a standalone service other than master > > > > > > > > > > > 2. Shell out from the master > > > > > > > > > > > > > > > > > > > > > > I don't think we have a good answer to (0), and I don't > > > think > > > > > > it's > > > > > > > > even > > > > > > > > > > > worth the effort of trying to build something when MR > is > > > > > already > > > > > > > > there, > > > > > > > > > > and > > > > > > > > > > > being used by HBase already for some operations. > > > > > > > > > > > > > > > > > > > > > > On (1), we have to deal with a myriad of issues - HA of > > the > > > > > > server > > > > > > > > not > > > > > > > > > > > being the least of them all. Security (kerberos > > > > authentication, > > > > > > > > another > > > > > > > > > > > keytab to manage, etc. etc. etc.). IMO, that approach > is > > > DOA. > > > > > > > Instead > > > > > > > > > > let's > > > > > > > > > > > substitute that (1) with the HBase Master. I haven't > seen > > > any > > > > > > good > > > > > > > > > reason > > > > > > > > > > > why the HBase master shouldn't launch MR jobs if > needed. > > > It's > > > > > not > > > > > > > > > ideal; > > > > > > > > > > > agreed. > > > > > > > > > > > > > > > > > > > > > > Now before going to (2), let's see what are the > benefits > > of > > > > > > running > > > > > > > > the > > > > > > > > > > > backup/restore jobs from the master. I think Ted has > > > > summarized > > > > > > > some > > > > > > > > of > > > > > > > > > > the > > > > > > > > > > > issues that we need to take care of - basically, the > > master > > > > can > > > > > > > keep > > > > > > > > > > track > > > > > > > > > > > of running jobs, and should it fail, the backup master > > can > > > > > > continue > > > > > > > > > > keeping > > > > > > > > > > > track of it (since the jobId would have been recorded > in > > > the > > > > > proc > > > > > > > > WAL). > > > > > > > > > > The > > > > > > > > > > > master can also do cleanup, etc. of failed > backup/restore > > > > > > > processes. > > > > > > > > > > > Security is another issue - the job needs to run as > > 'hbase' > > > > > since > > > > > > > it > > > > > > > > > owns > > > > > > > > > > > the data. Having the master launch the job makes it get > > > that > > > > > > > > privilege. > > > > > > > > > > In > > > > > > > > > > > the (2) approach, it's hard to do some of the above > > > > management. > > > > > > > > > > > > > > > > > > > > > > Guys, just to reiterate, the patch as such is ready > from > > > the > > > > > > > overall > > > > > > > > > > > design/arch point of view (maybe code review is still > > > pending > > > > > > from > > > > > > > > > > Matteo). > > > > > > > > > > > If in the future, we find better ways of doing this > > without > > > > > using > > > > > > > MR, > > > > > > > > > we > > > > > > > > > > > can certainly consider that. But IMO don't think we > > should > > > > > block > > > > > > > this > > > > > > > > > > patch > > > > > > > > > > > from getting merged. > > > > > > > > > > > > > > > > > > > > > > ________________________________________ > > > > > > > > > > > From: 张铎 <palomino...@gmail.com> > > > > > > > > > > > Sent: Thursday, September 22, 2016 8:32 PM > > > > > > > > > > > To: dev@hbase.apache.org > > > > > > > > > > > Subject: Re: [DISCUSSION] MR jobs started by Master or > RS > > > > > > > > > > > > > > > > > > > > > > So what about a standalone service other than master? > You > > > can > > > > > use > > > > > > > > your > > > > > > > > > > own > > > > > > > > > > > procedure store in that service? > > > > > > > > > > > > > > > > > > > > > > 2016-09-23 11:28 GMT+08:00 Ted Yu <yuzhih...@gmail.com > >: > > > > > > > > > > > > > > > > > > > > > > > An earlier implementation was client driven. > > > > > > > > > > > > > > > > > > > > > > > > But with that approach, it is hard to resume if there > > is > > > > > error > > > > > > > > > midway. > > > > > > > > > > > > Using Procedure V2 makes the backup / restore more > > > robust. > > > > > > > > > > > > > > > > > > > > > > > > Another consideration is for security. It is hard to > > > > enforce > > > > > > > > security > > > > > > > > > > (to > > > > > > > > > > > > be implemented) for client driven actions. > > > > > > > > > > > > > > > > > > > > > > > > Cheers > > > > > > > > > > > > > > > > > > > > > > > > > On Sep 22, 2016, at 8:15 PM, Andrew Purtell < > > > > > > > > > > andrew.purt...@gmail.com> > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > > No, this misses Matteo's finer point, which is > > > "shelling > > > > > out" > > > > > > > > from > > > > > > > > > > the > > > > > > > > > > > > master directly to run MR is a first. Why not drive > > this > > > > > with a > > > > > > > > > utility > > > > > > > > > > > > derived from Tool? > > > > > > > > > > > > > > > > > > > > > > > > > > On Sep 22, 2016, at 7:57 PM, Vladimir Rodionov < > > > > > > > > > > vladrodio...@gmail.com > > > > > > > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > > > > > > > > > > > > > > >>>> In our production cluster, it is a common case > we > > > > just > > > > > > have > > > > > > > > > HDFS > > > > > > > > > > > and > > > > > > > > > > > > >>>> HBase deployed. > > > > > > > > > > > > >>>> If our Master/RS depend on MR framework > > (especially > > > > some > > > > > > > > > features > > > > > > > > > > we > > > > > > > > > > > > >>>> have not used at all), it introduced another > cost > > > for > > > > > > > > maintain. > > > > > > > > > > I > > > > > > > > > > > > >>>> don't think it is a good idea. > > > > > > > > > > > > >> > > > > > > > > > > > > >> So , you are not backup users in this case. Many > our > > > > > > customers > > > > > > > > > have > > > > > > > > > > > full > > > > > > > > > > > > >> stack deployed and > > > > > > > > > > > > >> want see backup to be a standard feature. Besides > > > this, > > > > > > > nothing > > > > > > > > > will > > > > > > > > > > > > happen > > > > > > > > > > > > >> in your cluster > > > > > > > > > > > > >> if you won't be doing backups. > > > > > > > > > > > > >> > > > > > > > > > > > > >> This discussion (we do not want see M/R > dependency) > > > goes > > > > > to > > > > > > > > > nowhere. > > > > > > > > > > > We > > > > > > > > > > > > >> asked already, at least twice, to suggest another > > > > > framework > > > > > > > > (other > > > > > > > > > > > than > > > > > > > > > > > > M/R) > > > > > > > > > > > > >> for bulk data copy with *conversion*. Still > waiting > > > for > > > > > > > > > suggestions. > > > > > > > > > > > > >> > > > > > > > > > > > > >> -Vlad > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >> > > > > > > > > > > > > >>> On Thu, Sep 22, 2016 at 7:49 PM, Ted Yu < > > > > > > yuzhih...@gmail.com > > > > > > > > > > > > > > > > > > wrote: > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> If MR framework is not deployed in the cluster, > > hbase > > > > > still > > > > > > > > > > functions > > > > > > > > > > > > >>> normally (post merge). > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> In terms of build time dependency, we have long > > been > > > > > > > depending > > > > > > > > on > > > > > > > > > > > > >>> mapreduce. Take a look at ExportSnapshot. > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> Cheers > > > > > > > > > > > > >>> > > > > > > > > > > > > >>> On Thu, Sep 22, 2016 at 7:42 PM, Heng Chen < > > > > > > > > > > heng.chen.1...@gmail.com > > > > > > > > > > > > > > > > > > > > > > > > >>> wrote: > > > > > > > > > > > > >>> > > > > > > > > > > > > >>>> In our production cluster, it is a common case > we > > > > just > > > > > > have > > > > > > > > > HDFS > > > > > > > > > > > and > > > > > > > > > > > > >>>> HBase deployed. > > > > > > > > > > > > >>>> If our Master/RS depend on MR framework > > (especially > > > > some > > > > > > > > > features > > > > > > > > > > we > > > > > > > > > > > > >>>> have not used at all), it introduced another > cost > > > for > > > > > > > > maintain. > > > > > > > > > > I > > > > > > > > > > > > >>>> don't think it is a good idea. > > > > > > > > > > > > >>>> > > > > > > > > > > > > >>>> 2016-09-23 10:28 GMT+08:00 张铎 < > > > palomino...@gmail.com > > > > >: > > > > > > > > > > > > >>>>> To be specific, for example, our nice > > > Backup/Restore > > > > > > > feature, > > > > > > > > > if > > > > > > > > > > we > > > > > > > > > > > > >>> think > > > > > > > > > > > > >>>>> this is not a core feature of HBase, then we > > could > > > > make > > > > > > it > > > > > > > > > depend > > > > > > > > > > > on > > > > > > > > > > > > >>> MR, > > > > > > > > > > > > >>>>> and start a standalone BackupManager instance > > that > > > > > > submits > > > > > > > MR > > > > > > > > > > jobs > > > > > > > > > > > to > > > > > > > > > > > > >>> do > > > > > > > > > > > > >>>>> periodical maintenance job. And if we think > this > > > is a > > > > > > core > > > > > > > > > > feature > > > > > > > > > > > > that > > > > > > > > > > > > >>>>> everyone should use it, then we'd better > > implement > > > it > > > > > > > without > > > > > > > > > MR > > > > > > > > > > > > >>>>> dependency, like DLS. > > > > > > > > > > > > >>>>> > > > > > > > > > > > > >>>>> Thanks. > > > > > > > > > > > > >>>>> > > > > > > > > > > > > >>>>> 2016-09-23 10:11 GMT+08:00 张铎 < > > > palomino...@gmail.com > > > > >: > > > > > > > > > > > > >>>>> > > > > > > > > > > > > >>>>>> I‘m -1 on let master or rs launch MR jobs. It > is > > > OK > > > > > that > > > > > > > > some > > > > > > > > > of > > > > > > > > > > > our > > > > > > > > > > > > >>>>>> features depend on MR but I think the bottom > > line > > > is > > > > > > that > > > > > > > we > > > > > > > > > > > should > > > > > > > > > > > > >>>> launch > > > > > > > > > > > > >>>>>> the jobs from outside manually or by other > > > services. > > > > > > > > > > > > >>>>>> > > > > > > > > > > > > >>>>>> 2016-09-23 9:47 GMT+08:00 Andrew Purtell < > > > > > > > > > > > andrew.purt...@gmail.com > > > > > > > > > > > > >: > > > > > > > > > > > > >>>>>> > > > > > > > > > > > > >>>>>>> Ok, got it. Well "shelling out" is on the > line > > I > > > > > think, > > > > > > > so > > > > > > > > a > > > > > > > > > > fair > > > > > > > > > > > > >>>>>>> question. > > > > > > > > > > > > >>>>>>> > > > > > > > > > > > > >>>>>>> Can this be driven by a utility derived from > > Tool > > > > > like > > > > > > > our > > > > > > > > > > other > > > > > > > > > > > MR > > > > > > > > > > > > >>>> apps? > > > > > > > > > > > > >>>>>>> The issue is needing the AccessController to > > > decide > > > > > if > > > > > > > > > allowed? > > > > > > > > > > > But > > > > > > > > > > > > >>>> nothing > > > > > > > > > > > > >>>>>>> prevents the user from running the job > > > > > > > > > manually/independently, > > > > > > > > > > > > right? > > > > > > > > > > > > >>>>>>> > > > > > > > > > > > > >>>>>>>> On Sep 22, 2016, at 3:44 PM, Matteo > Bertozzi < > > > > > > > > > > > > >>>> theo.berto...@gmail.com> > > > > > > > > > > > > >>>>>>> wrote: > > > > > > > > > > > > >>>>>>>> > > > > > > > > > > > > >>>>>>>> just a remark. my query was not about tools > > > using > > > > MR > > > > > > > > > > (everyone i > > > > > > > > > > > > >>>> think > > > > > > > > > > > > >>>>>>> is > > > > > > > > > > > > >>>>>>>> ok with those). > > > > > > > > > > > > >>>>>>>> the topic was about: "are we ok with running > > MR > > > > jobs > > > > > > > from > > > > > > > > > > Master > > > > > > > > > > > > >>> and > > > > > > > > > > > > >>>> RSs > > > > > > > > > > > > >>>>>>>> code?" since this will be the first time we > do > > > > this > > > > > > > > > > > > >>>>>>>> > > > > > > > > > > > > >>>>>>>> Matteo > > > > > > > > > > > > >>>>>>>> > > > > > > > > > > > > >>>>>>>> > > > > > > > > > > > > >>>>>>>>> On Thu, Sep 22, 2016 at 2:49 PM, Devaraj > Das > > < > > > > > > > > > > > > >>> d...@hortonworks.com> > > > > > > > > > > > > >>>>>>> wrote: > > > > > > > > > > > > >>>>>>>>> > > > > > > > > > > > > >>>>>>>>> Very much agree; for tools like > > ExportSnapshot > > > / > > > > > > > Backup / > > > > > > > > > > > > Restore, > > > > > > > > > > > > >>>> it's > > > > > > > > > > > > >>>>>>>>> fine to be dependent on MR. MR is the right > > > > > framework > > > > > > > for > > > > > > > > > > such. > > > > > > > > > > > > We > > > > > > > > > > > > >>>>>>> should > > > > > > > > > > > > >>>>>>>>> also do compactions using MR (just saying > :) > > ) > > > > > > > > > > > > >>>>>>>>> ________________________________________ > > > > > > > > > > > > >>>>>>>>> From: Ted Yu <yuzhih...@gmail.com> > > > > > > > > > > > > >>>>>>>>> Sent: Thursday, September 22, 2016 2:00 PM > > > > > > > > > > > > >>>>>>>>> To: dev@hbase.apache.org > > > > > > > > > > > > >>>>>>>>> Subject: Re: [DISCUSSION] MR jobs started > by > > > > Master > > > > > > or > > > > > > > RS > > > > > > > > > > > > >>>>>>>>> > > > > > > > > > > > > >>>>>>>>> I agree - backup / restore is in the same > > > > category > > > > > as > > > > > > > > > import > > > > > > > > > > / > > > > > > > > > > > > >>>> export. > > > > > > > > > > > > >>>>>>>>> > > > > > > > > > > > > >>>>>>>>> On Thu, Sep 22, 2016 at 1:58 PM, Andrew > > > Purtell < > > > > > > > > > > > > >>>>>>> andrew.purt...@gmail.com> > > > > > > > > > > > > >>>>>>>>> wrote: > > > > > > > > > > > > >>>>>>>>> > > > > > > > > > > > > >>>>>>>>>> Backup is extra tooling around core in my > > > > opinion. > > > > > > > Like > > > > > > > > > > import > > > > > > > > > > > > or > > > > > > > > > > > > >>>>>>> export. > > > > > > > > > > > > >>>>>>>>>> Or the optional MOB tool. It's fine. > > > > > > > > > > > > >>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> On Sep 22, 2016, at 1:50 PM, Matteo > > Bertozzi > > > < > > > > > > > > > > > > >>>> mberto...@apache.org> > > > > > > > > > > > > >>>>>>>>>> wrote: > > > > > > > > > > > > >>>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> What's the latest opinion around running > MR > > > > jobs > > > > > > from > > > > > > > > > hbase > > > > > > > > > > > > >>>> (Master > > > > > > > > > > > > >>>>>>> or > > > > > > > > > > > > >>>>>>>>>> RS)? > > > > > > > > > > > > >>>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> I remember in the past that there was > > > > discussion > > > > > > > about > > > > > > > > > not > > > > > > > > > > > > >>> having > > > > > > > > > > > > >>>> MR > > > > > > > > > > > > >>>>>>>>> has > > > > > > > > > > > > >>>>>>>>>>> direct dependency of hbase. > > > > > > > > > > > > >>>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> I think some of discussion where around > MOB > > > > that > > > > > > had > > > > > > > a > > > > > > > > MR > > > > > > > > > > job > > > > > > > > > > > > to > > > > > > > > > > > > >>>>>>>>> compact, > > > > > > > > > > > > >>>>>>>>>>> that later was transformed in a non-MR > job > > to > > > > be > > > > > > > > merged, > > > > > > > > > I > > > > > > > > > > > > think > > > > > > > > > > > > >>>> we > > > > > > > > > > > > >>>>>>>>> had a > > > > > > > > > > > > >>>>>>>>>>> similar discussion for log split/replay. > > > > > > > > > > > > >>>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> the latest is the new Backup feature > > > > > (HBASE-7912), > > > > > > > that > > > > > > > > > > runs > > > > > > > > > > > a > > > > > > > > > > > > >>> MR > > > > > > > > > > > > >>>> job > > > > > > > > > > > > >>>>>>>>>> from > > > > > > > > > > > > >>>>>>>>>>> the master to copy data or restore data. > > > > > > > > > > > > >>>>>>>>>>> (backup is also "not really core" as in.. > > if > > > > you > > > > > > > don't > > > > > > > > > use > > > > > > > > > > > > >>> backup > > > > > > > > > > > > >>>>>>>>> you'll > > > > > > > > > > > > >>>>>>>>>>> not end up running MR jobs, but this was > > > > probably > > > > > > > true > > > > > > > > > for > > > > > > > > > > > MOB > > > > > > > > > > > > >>> as > > > > > > > > > > > > >>>> in > > > > > > > > > > > > >>>>>>>>> "if > > > > > > > > > > > > >>>>>>>>>>> you don't enable MOB you don't need MR") > > > > > > > > > > > > >>>>>>>>>>> > > > > > > > > > > > > >>>>>>>>>>> any thoughts? do we a rule that says "we > > > don't > > > > > want > > > > > > > to > > > > > > > > > have > > > > > > > > > > > > >>> hbase > > > > > > > > > > > > >>>> run > > > > > > > > > > > > >>>>>>>>> MR > > > > > > > > > > > > >>>>>>>>>>> jobs, only tool started manually by the > > user > > > > can > > > > > do > > > > > > > > > that". > > > > > > > > > > or > > > > > > > > > > > > >>> can > > > > > > > > > > > > >>>> we > > > > > > > > > > > > >>>>>>>>>> start > > > > > > > > > > > > >>>>>>>>>>> adding MR calls around without problems? > > > > > > > > > > > > >>> > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > -- Best regards, - Andy Problems worthy of attack prove their worth by hitting back. - Piet Hein (via Tom White)
