The characteristics of packet delays among edge networks in the Internet can have a significant impact on the performance and scalability of global-scale distributed systems. Designers rely on simulation to study design alternatives for such systems at scale, which requires an appropriate model of the Internet delay space. The model must preserve the ...

The fundamental feature of an OpenFlow network is that the controller is responsible for the initial establishment of every flow by contacting related switches. Thus the performance of the controller could be a bottleneck. This paper shows how this fundamental problem is addressed by parallelism. The state of the art OpenFlow controller, called NOX, ...

Distributed control protocols routinely have to operate oblivious of dynamic network information for scalability or complexity reasons. However, more informed protocols are likely to make more intelligent decisions. We argue that protocols can leverage dynamic congestion information without suffering the mentioned penalties. In this paper we show ...

The fundamental feature of an OpenFlow network is that the controller is responsible for the configuration of switches for every traffic flow. This feature brings programmability and flexibility, but also puts the controller in a critical role in the performance of an OpenFlow network. To fairly service requests from different switches, to achieve ...

Multi-tier applications are widely deployed in today’s virtualized cloud computing environments. At the same time, management operations in these virtualized environments, such as load balancing, hardware maintenance, workload consolidation, etc., often make use of live virtual machine (VM) migration to control the placement of VMs. Although existing ...

Failures are common in today’s data center environment and can significantly impact the performance of important jobs running on top of large scale computing frameworks. In this paper we analyze Hadoop’s behavior under compute node and process failures. Surprisingly, we find that even a single failure can have a large detrimental effect on job running ...

Network operation is inherently complex because it consists of many functions such as routing, firewalling, VPN provisioning, traffic load-balancing, network maintenance, etc. To cope with this, network designers have created modular components to handle each function. Un fortunately, in reality, unavoidable dependencies exist between some of the ...

The increasing number of datacenter applications with heavy one-to-many communications has raised the need for an efficient group data delivery solution. This paper presents an unconventional clean-slate architecture called λ group that uses optical networking technologies to enable ultra-fast, energy-efficient, low cost, and highly reliable group ...

Recent studies have discovered that the Internet delay space has many interesting properties such as triangle inequality violations (TIV), clustering structures, and constrained growth. Understanding these properties has so far benefited the design of network models and network-performance-aware systems. In this paper, we consider an interesting, ...

In this document, we show that the count to infinity behavior in the RSTP protocol can lead to a temporary forwarding loop in an Ethernet network.