SYNC process

["Somashekarappa, Anup" <an...@rbc.com>]

Hello Team,

We do have master-slave configuration for SVN and we were planning for
Disaster Recovery plan.

We need some information regarding this process.

*	We have created a repository on master node.
*	Initialized the slave node with master
*	And through post-commit we are using svn sync process for
synchronization.It is working fine.

Now if the master server is down,we have direct users to do the commit
on slave node.

But later when the master server is back,how can we make both servers to
be on same revision?

Thanks & Regards,
Anup T S

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Re: SYNC process

[Nico Kadel-Garcia <nk...@gmail.com>]

On Thu, Mar 28, 2013 at 10:34 AM, Somashekarappa, Anup
<an...@rbc.com> wrote:
>
>
> Hello Team,
>
> We do have master-slave configuration for SVN and we were planning for
> Disaster Recovery plan.
>
> We need some information regarding this process.
>
> We have created a repository on master node.
> Initialized the slave node with master
> And through post-commit we are using svn sync process for synchronization.It
> is working fine.
>
> Now if the master server is down,we have direct users to do the commit on
> slave node.

You have to shoot the old master in the head and re-establish the
master slave roles, reversed. Otherwise, you will encounter
"split-brain" madness. There are nice commercial solutions from
Wandisco that address precisely this situation: I'd highly recommend
using them instead of trying to brew this on your own, because
synchronizing and replicating other communications and failing over
gracefully can get quite tricky, and they've convinced me from their
explanations here that they're doing it correctly.

Re: SYNC process

[Daniel Shahaf <d....@daniel.shahaf.name>]

Andy Levy wrote on Thu, Mar 28, 2013 at 20:10:10 -0400:
> You can probably sync from slave to master without reinitializing the
> repository when you make the switch back.

'svnsync init --allow-non-empty'

Re: SYNC process

[Andy Levy <an...@gmail.com>]

On Thu, Mar 28, 2013 at 10:34 AM, Somashekarappa, Anup
<an...@rbc.com> wrote:
>
>
>
> Hello Team,
>
> We do have master-slave configuration for SVN and we were planning for
> Disaster Recovery plan.
>
> We need some information regarding this process.
>
> We have created a repository on master node.
> Initialized the slave node with master
> And through post-commit we are using svn sync process for
> synchronization.It is working fine.
>
> Now if the master server is down,we have direct users to do the commit on
> slave node.
>
> But later when the master server is back,how can we make both servers to
> be on same revision?

You have two options:

1) Leave it. The slave is now the master,
2) Reverse the process. Set up a new repository on the old master and
sync from the old slave. Once they're in sync, reverse the roles of
the two systems, much like how you made the slave into the master when
the original master went down.

You can probably sync from slave to master without reinitializing the
repository when you make the switch back.