-----------
Tel-Aviv University - Computer Science Colloquium

Sunday, January 30, 14:15-15:15
COFFEE at 14:00

Schreiber Building, Room 309
-----------

Proactive DNS Caching: Addressing a Performance Bottleneck

Edith Cohen

AT&T Labs - Research

Abstract:

The resolution of a host name to an IP-address is a necessary
predecessor to connection establishment and HTTP exchanges between
Web hosts. The Domain Name System, responsible for translating between
hostnames and IP-addresses, is a large distributed database.  While
its design accomodated the explosive rise in Web traffic and size of
the domain-name space, DNS resolutions inherently involve
communication with one or more remote name-servers.  Hence, when a
resolution can not be processed from the local cache, it often
considerably prolongs user-perceived latency.

DNS lookup times exhibit high variance, even when resolving the same
hostname.  For well-connected clients, DNS lookups are a dominant
cause of pathological delays.  Hence, they increase the inconsistency
in the quality of Internet-service.  Furthermore, DNS lookup time is
not addressed by continuing improvements such as higher-availablity
Web sites and increased bandwidth. Thus, as the quality of Internet
service rises, the degrading effect of DNS lookup time becomes even
more noticeable.

This performance bottleneck can be addressed by increasing local
availability of DNS records.  We propose and evaluate enhancements to
DNS caching which do so.  Our approaches operate on top and
consistently with DNS, and require only local deployment to be
effective.

 This is joint work with Haim Kaplan.
 

-----------

For colloquium schedule, see http://www.math.tau.ac.il/~zwick/colloq.html