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Our USENIX ATC paper presentation “Reexamining Direct Cache Access to Optimize I/O Intensive Applications for Multi-hundred-gigabit Networks”

At USENIX ATC 2020, Alireza presented our paper titled “Reexamining Direct Cache Access to Optimize I/O Intensive Applications for Multi-hundred-gigabit Networks”.  Full materials (video, slides, PDF) are available at the USENIX site. The paper abstract is below. This is joint work with Alireza Farshin, Amir Roozbeh, Gerald Q. Maguire Jr., and Dejan Kostić.

Memory access is the major bottleneck in realizing multi-hundred-gigabit networks with commodity hardware, hence it is essential to make good use of cache memory that is a faster, but smaller memory closer to the processor. Our goal is to study the impact of cache management on the performance of I/O intensive applications. Specifically, this paper looks at one of the bottlenecks in packet processing, i.e., direct cache access (DCA). We systematically studied the current implementation of DCA in Intel ® processors, particularly Data Direct I/O technology (DDIO), which directly transfers data between I/O devices and the processor’s cache. Our empirical study enables system designers/developers to optimize DDIO-enabled systems for I/O intensive applications. We demonstrate that optimizing DDIO could reduce the latency of I/O intensive network functions running at 100Gbps by up to ~30%. Moreover, we show that DDIO causes a 30% increase in tail latencies when processing packets at 200Gbps , hence it is crucial to selectively inject data into the cache or to explicitly bypass it.

Our upcoming IEEE Access article “Fast Deployment of Reliable Distributed Control Planes with Performance Guarantees”

Having published an NOMS 2018 paper on reliable distributed control planes, we continued working on this important problem and added an angle of guaranteed performance. Besides filing for a patent application, the work culminated in an IEEE Access article title “Fast Deployment of Reliable Distributed Control Planes with Performance Guarantees“. Full abstract is as follows:

Current trends strongly indicate a transition towards large-scale programmable networks with virtual network functions. In such a setting, deployment of distributed control planes will be vital for guaranteed service availability and performance. Moreover, deployment strategies need to be completed quickly in order to respond flexibly to varying network conditions. We propose an effective optimization approach that automatically decides on the needed number of controllers, their locations, control regions, and traffic routes into a plan which fulfills control flow reliability and routability requirements, including bandwidth and delay bounds. The approach is also fast: the algorithms for bandwidth and delay bounds can reduce the running time at the level of 50x and 500x, respectively, compared to state-of-the-art and direct solvers such as CPLEX. Altogether, our results indicate that computing a deployment plan adhering to predetermined performance requirements over network topologies of various sizes can be produced in seconds and minutes, rather than hours and days. Such fast allocation of resources that guarantees reliable connectivity and service quality is fundamental for elastic and efficient use of network resources.

The work was done at RISE by Shaoteng Liu, Rebecca Steinert, Natalia Vesselinova, and Dejan Kostić.




Second meeting with the Industrial Advisory Board (IAB)

On November 22, 2019 we had our second meeting with the Industrial Advisory Board (IAB). Present for part or most of the day were:

  • Azimeh Sefidcon and Björn Skubic, Ericsson
  • Ulrik Janusson, Scania
  • Shahryar Khan, Telia

We presented our status, published work, and short- and long-term plans. The IAB feedback was positive, and we are very excited to explore further ways our work can be of use to the Swedish industry!

Below are the images from the poster session held at RISE:

Rebecca presents the overview of the work at RISE
The car from the 2018 demo in front of the RISE poster. The car was controlled through the testbed that integrated all the work in this project




Waleed explains the work on Kurma [SOCC ’18]
Akhila talks about her Software Defined Radio (SDR)-powered testbed measurements (parts of it in the foreground)
Shaoteng explains the work on deploying distributed control planes
Alireza talks about the CacheDirector work that was patented with Ericsson
Alexandros describes the work on detecting IP prefix hijacking



KTH Inauguration on November 15, 2019

Yesterday was a superb day for us, with the KTH graduation taking place at the Stockholm’s concert hall, followed by the banquet at the Stockholm City Hall. Kirill and Georgios received their PhD degrees, and here is how we looked!

From the left: Georgios Katsikas, Dejan Kostic, and Kirill Bogdanov