Skip to main content

IBM Leadership Seminars

Seminar Navigation

Data Center Networking in the Cloud Era Technical Seminar
November 28, 2010
Organized by IBM R&D Labs in Israel
IBM Research Lab Auditorium, Haifa


Efficient Live Migration in the Cloud
Prof. Danny Raz, Technion

One of the big promises of cloud computing is the ability to provide high quality services at a low cost, which is a result of sharing the resources among many users (economy of scale). However, the fact that resources can be shared is by itself not sufficient to guarantee high availability of services with the needed QoS level at a reasonable cost. One has also to make sure that the use of resources is effective. A key building block in ensuring cost effective use of resources is the ability to move both applications and user data between different nodes in the cloud in an efficient way.

This talk addresses this point by studying efficient ways of application and data migration in the cloud. While live migration provides extreme versatility of management, it comes at a price of degraded service performance during migration. The bulk of studies devoted to live migration of virtual machines, focus on the duration of the copy phase as a primary metric of migration performance. While shorter down times are clearly desirable, the pre-copy phase imposes an overhead on the infrastructure that may result in severe performance degradation. We observe that there is a non-trivial trade-off between minimizing the copy phase duration and maintaining an acceptable quality of service during the pre-copy phase, and we introduce a new model to quantify this tradeoff. We then show that using our model, an optimal migration algorithm can be calculated efficiently. Finally, we simulate, using real traces, live migrations of a virtual machines running a search engine and compare the migration cost using our algorithm and commonly used live-migration methods.

This talk is based on joint paper with David Breitgand and Gilad Kutiel.

Network Virtualization
David Hadas, IBM

Virtual machines are of very little use if they cannot access the underlying physical network. Virtualizing the network has traditionally been considered a challenge best met by such network-centric measures as VLANs, implemented by switches. In this work, we present the benefits of adding network abstraction to hypervisors, moving the responsibility for network virtualization from the network to the server. Modern hypervisors do a poor job in virtualizing the network, leaking details of the physical network into virtual machines. For example, IP addresses used across the host's physical network, are exposed to guest virtual machines. We propose a method for plugging the network-related leaks by ensuring that the virtual network traffic is encapsulated inside a host envelope prior to transmission across the underlying physical network.

IBM's PowerEN Developer Cloud: Fertile Ground for Academic Research
Amit Golander, IBM

The Power Edge of Network(PowerEN) processor, recently announced by IBM, merges network and server attributes to create a wire-speed processor. PowerEN is a hybrid computer that employs: massive multithreading capabilities, integrated I/O and unique special-purpose accelerators for compression, cryptography, pattern matching, XML and Ethernet.

As a novel architecture, the PowerEN processor offers fertile ground for research. It can facilitate the development of faster applications in many fields of computer science such as Networking, Cryptography, Virtualization, Bioinformatics, SOA, and Systems. IBM encourages academic research and has set up the "PowerEN Developer Cloud" infrastructure to allow it. Israeli universities are of the first to perform research on this global infrastructure.

Optimizing Application Delivery for Cloud Services
Amir Peles, Radware

Amir Peles is the Chief Technology Officer of Radware, the leading Application Delivery and Application Security company. As virtualization and cloud computing take off as the leading trends in enterprise and Telco IT departments, they also bring challenges in maintaining user quality of experience. Amir will be presenting the unique advantages of smart application delivery for optimizing the Virtual Data Center and Cloud Services. A special focus will be given to the management of the Application Delivery functions as part of the overall data center and cloud management solution.

Distributed Oblivious Load Balancing Using Prioritized Job Replication
Amir Nahir, Technion

Distributed Oblivious Load Balancing Using Prioritized Job Replication" Effective load balancing in large distributed server systems is a highly complex optimization problem, which often involves multiple objectives and many parameters.
Irrespective of the precise optimization criteria, any attempt to address such an optimization problem would incur significant overhead due to the need to collect the required (state-dependent) information from the various servers.

In this study we propose to tackle the problem through an oblivious approach, i.e., a distributed load-sharing scheme that does not use any state information. Our scheme is based on creating, in addition to the regular job requests that are assigned to a randomly chosen server, also low priority job request replicas that are sent to a different server. We show that, when servers can coordinate the removal of redundant copies upon completion of a job, the performance of the system exhibits significant improvement of up to a factor of $2.2$, even under high load conditions, if job lengths are exponentially distributed, and a more dramatic improvement of over a factor of $5$ for typical loads, when job lengths adhere to a heavy-tailed distribution.
For cases where such coordination is not feasible, we propose simple, coordination-free schemes, which still yield a significant improvement of up to a factor of $1.15$ for exponentially distributed job lenghts and up to a factor of over $1.5$ for the heavy-tailed case.
We then design a hybrid scheme, which, while requiring just limited coordination, retains the main benefits of the full-coordination scheme. Finally, we demonstrate the benefit of our prioritized-replicas approach also within the realm of non-oblivious and centralized schemes.

This talk is based on joint paper with Danny Raz and Ariel Orda.

Leadership Seminars by year