AW: Why are XFRs to Secondaries equally fast?

[Klaus Darilion]

Hi Petr!

> > For example, there are 8 secondaries (Mumbai, LosAngeles, Melbourne,
> > Atlante, SaoPaulo...) to which the XFR took 2361 seconds.
> >
> > Are there some mechanisms in Bind that put multiple XFRs together into
> a
> > common stream? Or do you have any other ideas how it come that several
> > XFRs are equally fast?
> 
> Are you sure all these transfers were _actually_ running in parallel?

Yes. I checked the logs on the secondaries too and also these logs say that the XFR were finished at the same second.

> I suspect it will boil down to some sort of configured limit like
> transfers-out
> transfers-in
> transfers-per-ns
> serial-query-rate
> which cause some transfers to serialize and reduce parallelism.

$ egrep 'serial-query-rate|transfers' *
named.conf.options:        serial-query-rate 500;
named.conf.options:        transfers-in 50;        // number of total concurrent zone transfers from the masters to me
named.conf.options:        transfers-per-ns 50;    // number of concurrent zone transfers per master from the masters to me
named.conf.options:        transfers-out 200;      // number of concurrent zone transfers from me to my slaves

regards
Klaus