On Mon, Jan 13, 2014 at 10:07 AM, Petr Pudlák <[email protected]> wrote:
> Good idea. This would be another good improvement. We could update
> _last_written_ssconf only if all RPC calls that distribute it succeed. This
> way, if some fails, we'll try to redistribute it again on a next config
> update. But I'm a bit worried that this would slow ConfigWriter considerably
> if a node failed, especially if there were a network problem and trying to
> upload would end up with a network timeout. So it's a trade-off between
> trying to be consistent as much as possible and performance. What do you
> think?

Well, if a node is down and not *marked* offline things are horribly
slow anyway (try to check).
Also of course we need to consider nodes that are marked offline and
consider that normal.

>
> I guess this could be solved by uploading ssconf asynchronously, which would
> also speed up all configuration updates considerably, but I would rather
> focus on this in the WConfD daemon (ATM I'm not completely sure if ssconf
> falling a bit behind the master configuration would be OK, I haven't worked
> with ssconf very much). The same idea could be used for distributing the
> configuration to master candidates.
>

Yes, indeed, further improvements could go in the new daemon. I'm just
worried now not to make the situation worse. :)

Thanks,

Guido

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