Drop a specific rrset from cache?

[Felipe Gasper]

As a follow-up to this:

It appears that the daemon implements this functionality via its do_cache_remove() function. Would it be useful to put that functionality in libunbound?

-F


> On Aug 2, 2019, at 2:27 PM, Felipe Gasper via Unbound-users <unbound-users at nlnetlabs.nl> wrote:
> 
> Hello,
> 
> 	I’d like to implement something to detect changes to an RRSET. What I have is (pseudocode):
> 
> -----
> ctx = ub_ctx_create();
> 
> while (1) {
>    result = ub_ctx_resolve("example.com", "TXT");
>    sleep(5);
> 
>    _look_for_change(result);
> }
> -----
> 
> 	What I’m finding is that, because of libunbound’s caching, I’m getting the same result even long after changes have propagated to all of the relevant authoritative nameservers. If I set the “cache-max-ttl” option to 0 the problem goes away, but then I lose *all* caching, which I don’t want.
> 
> 	Is there a way to make libunbound forget/drop a _specific_ query’s result from its cache?
> 
> 	Thank you!
> 
> -Felipe Gasper
> Mississauga, Ontario