Nope, Mike. Fortunately, 99% of a FT code will remains after introducing
concurrent sessions support

Just two lines will be changed: TakeSnapshot -> BeginTX, RestoreSnapshot ->
RollbackTx

-Vlad

On Thu, Nov 30, 2017 at 7:20 PM, Mike Drob <[email protected]> wrote:

> Bringing this thread up again, because I don't really know where else to
> ask...
>
> The current backup&restore solution snapshots the backup metadata table and
> will restore-via-snapshot in case something goes wrong (or this is still in
> a patch? unclear if this has been committed or not, since there's a ton of
> code to dig through)
>
> AFAICT this is the major reason that we do not support concurrent backup or
> restore operations. (Are there others? Also couldn't find this.)
>
> The fault tolerance that we're working on now will need to be gutted and
> completely rewritten for the future improvements. I get that this is all
> internal and as long as we make it seamless for the operators then we have
> wide latitude to make our own changes. But an important question is just
> because we can, does it mean we should do this? I'm concerned that we're
> writing code that we know will get thrown away and replaced, except we will
> have to continue to support it for as long as 2.0 is an active branch.
>
> Mike
>
>
> On Wed, Nov 15, 2017 at 3:05 PM, Josh Elser <[email protected]> wrote:
>
> > On 11/14/17 4:54 PM, Mike Drob wrote:
> >
> >> I can see a small section on the documentation update I've already been
> >>> hacking on to include details on the issue "We can't help you secure
> >>> where
> >>> you put the data". Given how many instances of "globally readable S3
> >>> bucket" I've seen recently, this strikes me as prudent.
> >>>
> >>> I would prefer this to be a giant, hard to miss, red letters, all caps
> >> warning; not a small section. I do think it is our responsibility for
> >> telling users how to configure the backup/restore process for
> >> communicating
> >> with secure systems. Or, at a minimum, documenting how we pass arbitrary
> >> configuration options that can then be used to communicate with said
> >> systems.
> >>
> >
> > :D
> >
> > For example, if we support writing backups to S3, then we should have a
> way
> >> to specify an Auth string and maybe even some of the custom headers like
> >> x-amz-acl. We don't have to explicitly enumerate best practices, but if
> >> the
> >> only option is to write to a globally open bucket, then I don't think we
> >> should advertise writing to S3 as an available option.
> >>
> >> Similarly, if we tell people that they can send backups to HDFS, then we
> >> should give them the hooks to correctly interface with a kerberized
> HDFS.
> >>
> >> Maybe this is already in the proposed patch, I haven't gone looking yet.
> >>
> >
> > Nope. I actually meant to include this in the patch I re-rolled today but
> > forgot. Let me update once more.
> >
> > Thanks again, Mike. Good questions/feedback!
> >
>

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