8.8.8.8 server shows response delays that 8.8.4.4 does not

[Boonie...]

Hi,

I've been testing several DNS servers with Smokeping. It has been
doing automated queries to the google servers amongst others. I've
found that from NL, the 8.8.8.8 server shows that on busy hours that
there are response delays on a normal level of 10mS but also a lot is
on 70mS. Except an odd one, there are no responses in between. And
that is what puzzles me.

As said, this is not on 8.8.4.4 and not on off-peak hours.

If you like, I can send screen shots.

[Paul S. R. Chisholm]

Hi, Dave, thanks for your message. I'm not sure what you're trying to
say. Are these ping times? If so, that's interesting, but there may
not be much we can do with that information. If these are DNS response
times, then 10 ms responses are probably from our cache and 70 ms
responses are probably when we have to contact authoritative
nameservers.

I would not expect to see different delays on the two addresses,
unless you're testing 8.8.8.8 first and 8.8.4.4 second. In that case,
the first test is likely populating the cache (used by both
addresses), and the second test is likely getting all cached
responses.

Sure, please send me a screen shot, or whatever kind of output
Smokeping can product.

Thanks. --PSRC (software engineer, Google Public DNS)

[Boonie...]

Hi,

No, I'm not talking about ping. Completely separate from this issue, I
did pings and the issue is NOT related to network latency to the DNS
nodes. Just as a reference, pings are around 10mS for both DNS
servers.

I do automated DIG (nslookup). The response-time is graphed. Only
8.8.8.8 has response-times that are in 2 or 3 time ranges. So, a
response can take like about 10mS or about 70mS or about 120mS. But
not some value in between.

To me this says that the server seems to have an issue finding the
result and trying again after a timeout of (70-10) 60mS.

This issue is never seen on 8.8.4.4 while I do see it from two
different networks in the Netherlands.

I realy think you need to see the graphs. Would you like to receive
them by mail?

[dusti]

I noticed too that the 8.8.8.8 server is acting strange (for sure the
last month)
8.8.4.4 mostly resolves an ip that has been changed correct.
after querying 8.8.8.8 results returned are not always correct, (using
old IP, while just before that it resolved the new ip)
If I query 8.8.4.4 after querying 8.8.8.8 then first it returns a bad
result, then a good one.

If you ask me it seems that one of the servers in the 8.8.8.8 cluster
is not updating it's cache.

[Boonie...]

I never reported my issue solved. On December 6th I've seen the
slowness for the last time.

Dusty might want to make some traceroutes to 8.8.8.8 to see where the
server is that is responding to his requests. The one I'm using must
be in, or close to, Amsterdam.