Trial by Fire
On Monday, February 4, 2008, RF
Cafe began using the services of a company that provides proprietary DNS IP address
lookup and Internet data packet routing via private "Managed DNS" servers located
across the globe in strategic locations (see red dots on image below).
The prime motivation for subscribing
to this service (it is not cheap) is to make visiting RF Cafe as efficient as possible
for you. Efficiency as defined by my criteria is thus:
1) How quickly does
a page begin loading after you instruct your browser to fetch it?
long does it take the page to completely load once started?
3) Does the requested
page fail to either begin or complete loading?
The best way to meaningfully
gauge the user experience is to ask you, the user. Please take a moment to vote
in the poll below. You do not need to register - just click on the button that best
describes your experience. (Poll removed)
I spend a lot of time surfing the
Internet looking for data and links to data or articles to present to RF Cafe's
visitors. Being provided with lots of new and useful content is what (hopefully)
keeps you coming back again and again. In my daily quest, I visit a lot of websites;
a few are excellent, the vast majority are OK, and a few are downright atrocious.
Page load time is not as big of a deal as it was back when there were still a lot
of unfortunate souls still using dial-up service, but there are still some pages
out there (including on RF Cafe) that are so heavy on content that it can take three
to five seconds to fully load. If the slow loading time is due to a lot of large
images or due to some silly animated presentation that only the designer thinks
is cool and worth wasting your time on, then unless I really need what is being
offered, I leave the website.
Even more offensive to my fragile psyche is
the cursed full-page entry advertisement. I of all people realize the need for paying
advertisers to help underwrite the cost of maintaining a website, but personally
think those are going to far. Particularly insulting are the ones that have the
utterly untruthful message saying that the page you really want to see is loading,
implying that the ad is just there so you do not have to watch the page load. ...but
Believe it or not, I spend a very large fraction of my waking
hours working on RF Cafe. Call it dedication or an obsession, but if I spend time
doing anything other than creating content for the website, I feel as if I am neglecting
my duties. Always in the background of my RF Cafe activities is a real concern about
how each change or addition is going to affect the overall quality of the user's
experience. Will a busy engineer, manager, student, or even a hobbyist deem RF Cafe
truly useful, or just a waste of time? Having to wait a long time for pages to load
is definitely a waste of his/her time, so that is why I decided to employ a professional
service to help guarantee that every requested page is received without errors,
and then all of those in an acceptable amount of time.
I have merely a layman's knowledge of the way the Internet
works. The domain name system (DNS) functions within it to take a browser's request
for a certain web page using the alias that is a domain name and converts it to
an equivalent IP address, which is then used to fetch and deliver the page to the
browser. While the workings of the Internet are a well-defined and cogent set of
rules encoded in hardware and software throughout the world, the fact that everything
works so well (or at all) borders on the miraculous.
Rather than risk constructing my own inept explanation
for how this new "Managed DNS" service works to bring RF Cafe to you in a more effective
and efficient manner, I will resort to proving a few snippets of wisdom form the
company's website. In the spirit of
Linus Van Pelt
when responding to Charlie's famous question: Isn't there Anyone who knows what
"Managed DNS" is all about?
"The network currently consists
of a mesh of fourteen (14) globally synchronized
DNS server nodes located
on five (5) continents. By utilizing dedicated hardware, each major component of
the system is partitioned to function independently while providing a means of marshaling
access control. Hardware is transparently added to an existing node without negatively
impacting service at that node. Once a new DNS server is added, it immediately begins
announcing the appropriate Anycast addresses and is included in the pool of servers available
to answer queries within that node. Similarly, if a server fails, or is removed
for maintenance, it ceases announcing the Anycast addresses, and queries continue
to be received and answered by the remaining operational servers in that node with
no end-user impact.
Diverse network connectivity is utilized within the network.
Primary IPv4 connectivity
is provided by three International network carriers. Each node is multi-homed with
100 Mbps (Fast Ethernet) connections to each carrier. In addition, every node is
also connected natively to a global IPv6 network. Finally, each node is connected to the local public
peering fabric at that node, with a liberal peering policy. To ensure robustness
and redundancy, a carefully architected matrix of network announcements is utilized
to ensure that both minor and catastrophic failures of any elements within the network
will not result in failures of resolution for end users. This includes unique combinations
of network (IP address) announcements, network providers and collocation facility
operators so that the catastrophic failure of an entire backbone carrier, combined
with the failure of all facilities controlled by a collocation operator, would have
no material impact on the service levels provided to customers.
internetworking reliability and minimized resolution latency ****** offers are achieved
in part by the implementation of advanced IP Anycast techniques. The term 'Anycast'
describes packets being sent between a single source and the nearest (in terms of
network topology) of several possible destinations in a group, all having the same
IP address. Anycast is different from multicast (packets between a single source
and multiple, unique destinations) and unicast (packets between a single source
and a single destination).
(Border Gateway Protocol) route announcements from each node, the system leverages
the features of BGP to enable the routing of user queries to a topologically nearby
node, resulting in the following network efficiencies and advantages:
of network latency for DNS transactions, as compared with a 'standard' deployment
of DNS services. Reduction in the number of queries routed to distant servers, thereby
reducing the likelihood of encountering congested routers. Reduction in the number
of query packets that are dropped, and which then result in DNS timeouts/retries.
Improved performance and reliability to the end user. Utilizing Anycast, the same
six IP addresses are announced in different combinations from each DNS resolver
in the network infrastructure. This implementation provides additional redundancy
in the face of network routing problems that can be caused by third parties. In
the unlikely event that one or more of the IP addresses become unreachable, queries
from users are seamlessly directed to an alternate node, which is also announcing
the same IP address.
Anycast allows the geographical distribution of requests
to any available DNS resolver for redundancy to effectively distribute traffic/requests
to any given IP address globally, and to increase responsiveness of the overall
system by using the closest (in terms of network topology) available resource to
answer any query that enters the system."
... That's what "Managed DNS" is
all about, Charlie
For the time being, I will protect the identity of the company
- just in case RF Cafe does not realize the anticipated gain.
Posted January 10, 2008