Espresso makes Google cloud faster, more available and cost effective by extending SDN to the public internet

Today, we gave a keynote presentation at the Open Networking Summit, where we shared details about Espresso, Google’s peering edge architecture—the latest offering in our Software Defined Networking (SDN) strategy. Espresso has been in production for over two years and routes 20 percent of our total traffic to the internet—and growing. It’s changing the way traffic is directed at the peering edge, delivering unprecedented scale, flexibility and efficiency.


Cutting the Cord: a Robust Wireless Facilities Network for Data Centers

Today’s network control and management traffic are limited by
their reliance on existing data networks. Fate sharing in this context
is highly undesirable, since control traffic has very different availability
and traffic delivery requirements. In this paper, we explore
the feasibility of building a dedicated wireless facilities network for
data centers. We propose Angora, a low-latency facilities network
using low-cost, 60GHz beamforming radios that provides robust
paths decoupled from the wired network, and flexibility to adapt to
workloads and network dynamics. We describe our solutions to address
challenges in link coordination, link interference and network
failures. Our testbed measurements and simulation results show
that Angora enables large number of low-latency control paths to
run concurrently, while providing low latency end-to-end message
delivery with high tolerance for radio and rack failures.


Flexible Network Bandwidth and Latency Provisioning in the Datacenter

Predictably sharing the network is critical to achieving
high utilization in the datacenter. Past work has focussed
on providing bandwidth to endpoints, but often
we want to allocate resources among multi-node services.
In this paper, we present Parley, which provides
service-centric minimum bandwidth guarantees, which
can be composed hierarchically. Parley also supports
service-centric weighted sharing of bandwidth in excess
of these guarantees. Further, we show how to configure
these policies so services can get low latencies even at
high network load. We evaluate Parley on a multi-tiered
oversubscribed network connecting 90 machines, each
with a 10Gb/s network interface, and demonstrate that
Parley is able to meet its goals.


Gestalt: Fast, unified fault localization for networked systems

Abstract— We show that the performance of existing
fault localization algorithms differs markedly for different
networks; and no algorithm simultaneously provides
high localization accuracy and low computational overhead.
We develop a framework to explain these behaviors
by anatomizing the algorithms with respect to six
important characteristics of real networks, such as uncertain
dependencies, noise, and covering relationships. We
use this analysis to develop Gestalt, a new algorithm that
combines the best elements of existing ones and includes
a new technique to explore the space of fault hypotheses.
We run experiments on three real, diverse networks. For
each, Gestalt has either significantly higher localization
accuracy or an order of magnitude lower running time.
For example, when applied to the Lync messaging system
that is used widely within corporations, Gestalt localizes
faults with the same accuracy as Sherlock, while
reducing fault localization time from days to 23 seconds.


Trumpet: Timely and Precise Triggers in Data Centers

As data centers grow larger and strive to provide tight performance
and availability SLAs, their monitoring infrastructure
must move from passive systems that provide aggregated
inputs to human operators, to active systems that enable programmed
control. In this paper, we propose Trumpet, an
event monitoring system that leverages CPU resources and
end-host programmability, to monitor every packet and report
events at millisecond timescales. Trumpet users can express
many network-wide events, and the system efficiently detects
these events using triggers at end-hosts. Using careful design,
Trumpet can evaluate triggers by inspecting every packet at
full line rate even on future generations of NICs, scale to
thousands of triggers per end-host while bounding packet
processing delay to a few microseconds, and report events
to a controller within 10 milliseconds, even in the presence
of attacks. We demonstrate these properties using an implementation
of Trumpet, and also show that it allows operators
to describe new network events such as detecting correlated
bursts and loss, identifying the root cause of transient congestion,
and detecting short-term anomalies at the scale of a data
center tenant.


Lessons learned from B4, Google’s SDN WAN

Google’s B4 wide area network was first revealed several years ago. The outside observer might have thought, “Google’s B4 is finished. I wonder what they’re going to do next.” Turns out, once any network is in production @scale, there’s a continued need to make it better. Subhasree Mandal covered the reality of how Google iterated multiple times on different parts of B4 to improve its performance, availability, and scalability. Several of the challenges and solutions that Subhasree detailed were definitely at the intersection of networking and distributed systems. B4 was covered in a SIGCOMM 2013 paper from Google.