[Pdns-users] max record length workaround

Kenneth Marshall ktm at rice.edu
Wed Mar 20 20:23:00 UTC 2019

> On Mar 20, 2019, at 19:37, Jonathan Reed <jreed777 at gmail.com> wrote:
> >> TXT records are limited to strings of 255 characters or less, but can have multiple strings, They'll be concatenated in order by the DKIM validator - I'm guessing that's what you're thinking of.
> > Yes, indeed.
> > 
> > My pub key is 400 chars long, and inserting the long string as a set into records.content fails as expected.
> > mysql> UPDATE records set content = '"v=DKIM1; k=rsa; p=190_char_string" "200_more_chars"' where id = 1234;
> > ERROR 1406 (22001): Data too long for column 'content' at row 1
> There is no workaround. You’ll need to fix your database schema (that’d be trivial on postgresql, but I don’t know enough about mysql’s limitations to know whether it’ll be painful there).
> > 
> > Alternatively, adding a second row with the same records.name (same selector) makes sense.
> > mysql> UPDATE records set content = '"200_more_chars"' where id = 1235;
> That won’t work, ever. It needs to be a single TXT record.
> Cheers,
>   Steve

Hi Steve et. al.,

I think I remember needing to do this back in the 2.9.22 era and the
trick was to put the text records in with the same name, in order, in
the DB. PDNS concatenated them in ID order from the DB and it all
worked. You might want to give that a try.


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