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Re: Deprecating/removing PropertyFileSnitch?


> the new host won’t learn about the host whose status is missing and the
view of this host will be wrong.

Won't this happen even with PropertyFileSnitch as the token(s) for this
host will be missing from gossip/system.peers?

Em sáb, 20 de out de 2018 às 00:34, Sankalp Kohli <kohlisankalp@xxxxxxxxx>
escreveu:

> Say you restarted all instances in the cluster and status for some host
> goes missing. Now when you start a host replacement, the new host won’t
> learn about the host whose status is missing and the view of this host will
> be wrong.
>
> PS: I will be happy to be proved wrong as I can also start using Gossip
> snitch :)
>
> > On Oct 19, 2018, at 2:41 PM, Jeremy Hanna <jeremy.hanna1234@xxxxxxxxx>
> wrote:
> >
> > Do you mean to say that during host replacement there may be a time when
> the old->new host isn’t fully propagated and therefore wouldn’t yet be in
> all system tables?
> >
> >> On Oct 17, 2018, at 4:20 PM, sankalp kohli <kohlisankalp@xxxxxxxxx>
> wrote:
> >>
> >> This is not the case during host replacement correct?
> >>
> >> On Tue, Oct 16, 2018 at 10:04 AM Jeremiah D Jordan <
> >> jeremiah.jordan@xxxxxxxxx> wrote:
> >>
> >>> As long as we are correctly storing such things in the system tables
> and
> >>> reading them out of the system tables when we do not have the
> information
> >>> from gossip yet, it should not be a problem. (As far as I know GPFS
> does
> >>> this, but I have not done extensive code diving or testing to make
> sure all
> >>> edge cases are covered there)
> >>>
> >>> -Jeremiah
> >>>
> >>>> On Oct 16, 2018, at 11:56 AM, sankalp kohli <kohlisankalp@xxxxxxxxx>
> >>> wrote:
> >>>>
> >>>> Will GossipingPropertyFileSnitch not be vulnerable to Gossip bugs
> where
> >>> we
> >>>> lose hostId or some other fields when we restart C* for large
> >>>> clusters(~1000 instances)?
> >>>>
> >>>>> On Tue, Oct 16, 2018 at 7:59 AM Jeff Jirsa <jjirsa@xxxxxxxxx> wrote:
> >>>>>
> >>>>> We should, but the 4.0 features that log/reject verbs to invalid
> >>> replicas
> >>>>> solves a lot of the concerns here
> >>>>>
> >>>>> --
> >>>>> Jeff Jirsa
> >>>>>
> >>>>>
> >>>>>> On Oct 16, 2018, at 4:10 PM, Jeremy Hanna <
> jeremy.hanna1234@xxxxxxxxx>
> >>>>> wrote:
> >>>>>>
> >>>>>> We have had PropertyFileSnitch for a long time even though
> >>>>> GossipingPropertyFileSnitch is effectively a superset of what it
> offers
> >>> and
> >>>>> is much less error prone.  There are some unexpected behaviors when
> >>> things
> >>>>> aren’t configured correctly with PFS.  For example, if you replace
> >>> nodes in
> >>>>> one DC and add those nodes to that DCs property files and not the
> other
> >>> DCs
> >>>>> property files - the resulting problems aren’t very straightforward
> to
> >>>>> troubleshoot.
> >>>>>>
> >>>>>> We could try to improve the resilience and fail fast error checking
> and
> >>>>> error reporting of PFS, but honestly, why wouldn’t we deprecate and
> >>> remove
> >>>>> PropertyFileSnitch?  Are there reasons why GPFS wouldn’t be
> sufficient
> >>> to
> >>>>> replace it?
> >>>>>>
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> >>>>>
> >>>
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> >>>
> >
> >
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