Abstract:
The popularity of online services such as web search, advertisement, social
networking, and recommendation systems has lead to a proliferation of data
center networks in the last few years. These services share a few common
themes. First, they are soft real time nature. Consequently, the response
time of tasks determines the quality of results, which in turn impacts oper-
ators revenue. Second, data centers typically employ a Partition/Aggregate
work
ow pattern, in which user requests are partitioned amongst layers of
workers whose results are then aggregated. The returned responses from
workers are often synchronized, leading to the Incast problem. In addition,
data center applications generate a mix of tra c workloads. While most
ows
are short (<100 KB), a few long
ows can saturate the path. Consequently,
such
ows can lead to large queueing delays and thus a ect delay-sensitive
tra c.
In this work, we leverage the above characteristics to design a protocol
that seeks to reduce average
ow completion time (AFCT) within data cen-
ters. To this end, rst, we explore the e cacy of
ow size awareness for
reducing
ow completion times in data centers. Second, we present the de-
sign, analysis and evaluation of a size aware delivery control protocol (SDC)
which incorporates these features to to achieve small
ow completion times
while maintaining high network throughput and small queues. Third, we
present evaluation of a router assisted capacity sharing (RACS) framework.
Detailed performance analysis shows that RACS can improve AFCT of ap-
plications signi cantly, hence improve application throughput. Performance
comparison with existing schemes like rate control protocol (RCP) and TCP-
SACK shows that DC network performance can be signi cantly improved by
leveraging
ow size information at transport layer.
