Re: [PATCH] dnscache: merge similar outgoing udp packets

On Tue, Apr 21, 2009 at 3:10 PM, Jeff King <[email protected]> wrote:
> On Thu, Apr 16, 2009 at 05:26:40PM -0500, Mark Johnson wrote:
>
>> > This patch is only lightly tested. Use on production servers at your own
>> > risk (and please report to the list if you have success using it).
>>
>> This will be going into the much delayed zinq-djbdns-0.06.
>
> Thanks. The list has been silent on success reports, so perhaps nobody
> is actually using it. I've been running it for a few weeks now without
> incident, but only on a lightly loaded server (and only on dnscache --
> the changes shouldn't affect other programs, but I haven't tested it
> extensively).

I ran it for a few days before pushing it out and observed no problems
(and received no reports of problems) with dnscache or tinydns.

I don't know that zinq-djbdns actually has any users (as opposed to
downloaders), but if I get any trouble reports, I'll let you know.

>> Recommended value for MERGEQUERIES?  Obviously dnscache doesn't care,
>> but envdir will not set an environment variable if the corresponding
>> file is empty.  I'd be tempted to just use '1' or 'ON' except that
>> suggests you can turn query merging off by setting it to '0' or 'OFF',
>> when what they really have to do is remove the file or truncate it to
>> zero bytes.  Is there a best practice?  I do intend to modify
>> dnscache-conf to create a MERGEQUERIES file in the env directory so
>> that query merging is on by default in zinq-djbdns.
>
> I would just use "1", which I see you did in the new zinc release. I
> agree that the "0 still enables" behavior is confusing and has bitten
> people on the list, but I think it is better to be consistent with the
> existing options (which is why I implemented it as I did).
>
> -Peff

I slapped a note in INSTALL about disabling query merging.
Suggestions for better documentation always appreciated.