Axfr and AxfrStream issues with big zones about hickory-dns

[bluejekyll]

Yes, this is a known issue, I think it’s the same as reported here #351

[darnuria]

Oh thanks did a quick search about AXFR and stream and issue and didn't find out, was already late in Europe. Feel free to close I can report the info you think are useful there. :)

EDIT: Will try to spend some time reading carefully the other issue to checkout if it's really the same or if it add some info. Cannot promise to do it today but next-week I can try if you think it's worth it.

[bluejekyll]

A quick synopsis on this, I think to fix this we need to change or add a new method into the Authority/Catalog for this operation to properly work. Right now, if I remember correctly, we return the entire zone in a single call and then stream that back. That's bad for large zones. What we need is a continuation call, like get first 0..N record, get next N..(N + N) records, etc. That would allow us to properly stream back an entire very large zone.

We also probably have some other deficiencies that we will need to take care of as well, for example, we really need an on disk option for zone lookups and not store them entirely in memory. I think there might be an old issue for that.