Re: 100% failover + replication solution

Brad Nicholson wrote:
> Excellent addition.  I suggest in 24.1 - Shared Disk Failover something
> about the risk of having two postmasters come up on the same data
> directory, which is entirely possible if the old master doesn't release
> the disk in time.

I have added a mention of this.

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>
>
>
> On Tue, 2006-11-14 at 15:11 -0500, Bruce Momjian wrote:
> > I wrote this for the 8.2 documentation.  Let me know if it helps or you
> > have other suggestions:
> >
> >     http://developer.postgresql.org/pgdocs/postgres/failover.html
> >
> > ---------------------------------------------------------------------------
> >
> > Moiz Kothari wrote:
> > > Guys,
> > >
> > > I have been thinking about this and wanted to see if it can be achived. I
> > > wanted to make a 100% failover solution for my postgres databases. The first
> > > thing that comes to my mind is doing it using WAL logs. Am attaching the
> > > diagram for which i will write more here.
> > >
> > > I was thinking if i can have Hotsync the databases using the WAL logs. If
> > > you see the architecture, the select goes to the SLAVE nodes and the INSERTS
> > > goes to the MASTER database, that means there should be no transactions
> > > happening on SLAVES (pure select). not even using "plpgsql". In this
> > > archecture i wont even mind restarting the SLAVE nodes if i need to.
> > >
> > > I was reading on PIT recovery on postgres, the only current problem i am
> > > facing with that is, i need to backup the database and move the slaves and
> > > the apply WAL logs to it. That could be huge amount of transfer and hence a
> > > longer downtime then moving 16mb WAL log files.
> > >
> > > Can someone help me out here, what i want is a continuous applying of WAL
> > > logs once i have brought the database up. I want to elimiate the backup of
> > > master to be restored to the slaves everytime i want to apply WAL to slaves.
> > > It would be real help if someone can  tell me if it is possible to apply WAL
> > > logs to the slaves continously as soon as they are created on MASTER. I
> > > checked other tools available and thougth this would be best approach if it
> > > works.
> > >
> > > Awaiting reply soon.
> > >
> > > Regards,
> > > Moiz Kothari
> >
> > [ Attachment, skipping... ]
> >
> > >
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> >
> --
> Brad Nicholson  416-673-4106
> Database Administrator, Afilias Canada Corp.
>
>
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> TIP 5: don't forget to increase your free space map settings

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  Bruce Momjian   bruce@momjian.us
  EnterpriseDB    http://www.enterprisedb.com

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