Re: [Dproxy-devel] memory cache for top 100?

[Matty <mat...@ya...>]

qu...@ba... wrote:

> Hi all,
>         has anyone thought about implementing a memory cache for the top
> 100 or so dns lookups? This would definately be faster, especially for
> things like entries from /etc/hosts and deleteing timed out entries.
>
> I think putting the whole thing in memory would be good as you could then
> setup another thread which would purge the timedout cache entries and
> rewrite the file (Less IO = good);
>

Well the kernel should take care of caching the cache file (confused yet?),
so there should not be heaps of IO.
Besides compare a ~15ms disk seek time to a 650ms ping time over the modem.

I avoided memory based cache for two reasons: 1) if dproxy is unexpectedly
killed it doesnt loose its cache 2) my gateway does not have much RAM.

Similarly I didn't go with a threads aproach as it bloated dproxy, and again
I dont have much RAM.

Seems we should go two directions from here: 1) a dproxy-lite version that
stays small and doesn't have feature creep. Does the mininum job and thats
it. 2) a more featurefull version for either larger servers, or workstations.

>
> However, if the cache grows large this could be a downfall.
> Comments?
>
> Also, what's happening with getting dproxy working on the gateway machine.
> I know it means implenting the full dns protocol but I think it may be
> worth it.
>

Ask andi about his lastest work.

On that note, Andi can you put in in CVS under something like dproxy-new, or
dproxy-1.x...
Actually I dont know what permissions you have over the CVS, so if you cant
do it give us a yell and I will see if I can fix it.

Matty