MORPHOSYS: efficient colocation of QoS-constrained workloads in the cloud

In hosting environments such as IaaS clouds, desirable application performance is usually guaranteed through the use of Service Level Agreements (SLAs), which specify minimal fractions of resource capacities that must be allocated for use for proper operation. Arbitrary colocation of applications with different SLAs on a single host may result in inefficient utilization of the host’s resources. In this paper, we propose that periodic resource allocation and consumption models be used for a more granular expression of SLAs. Our proposed SLA model has the salient feature that it exposes flexibilities that enable the IaaS provider to safely transform SLAs from one form to another for the purpose of achieving more efficient colocation. Towards that goal, we present MorphoSys: a framework for a service that allows the manipulation of SLAs to enable efficient colocation of workloads. We present results from extensive trace-driven simulations of colocated Video-on-Demand servers in a cloud setting. The results show that potentially-significant reduction in wasted resources (by as much as 60%) are possible using MorphoSys.First author draf

Fresh Analysis of Streaming Media Stored on the Web

With the steady increase in the bandwidth available to end users and Web sites hosting user generated content, there appears to be more multimedia content on the Web than ever before. Studies to quantify media stored on the Web done in 1997 and 2003 are now dated since the nature, size and number of streaming media objects on the Web have changed considerably. Although there have been more recent studies characterizing specific streaming media sites like YouTube, there are only a few studies that focus on characterizing the media stored on the Web as a whole. We build customized tools to crawl the Web, identify streaming media content and extract the characteristics of the streaming media found. We choose 16 different starting points and crawled 1.25 million Web pages from each starting point. Using the custom built tools, the media objects are identified and analyzed to determine attributes including media type, media length, codecs used for encoding, encoded bitrate, resolution, and aspect ratio. A little over half the media clips we encountered are video. MP3 and AAC are the most prevalent audio codecs whereas H.264 and FLV are the most common video codecs. The median size and encoded bitrates of stored media have increased since the last study. Information on the characteristics of stored multimedia and their trends over time can help system designers. The results can also be useful for empirical Internet measurements studies that attempt to mimic the behavior of streaming media traffic over the Internet

Streaming media over the Internet: Flow based analysis in live access networks

Multimedia service delivery over the Internet is a success. The number of services available and the number of people accessing them is huge. In this paper, we investigate multimedia streaming services over the Internet. Our analysis is based on traffic measurement in live access fiber-to-the-home networks. We study parameters like traffic volume and flow characteristics for selected services. Especially the Swedish P2P video service Voddler and the Swedish P2P music service Spotify are studied. We show that indeed these services are widely used (20% of local hosts using Voddler, 65 % of local hosts using Spotify). We also show that they are different concerning the flow characteristics, with many short flows for Voddler and longer flows for Spotify. One thing that they have in common in our measurements is that the outbound, or uplink, traffic volume is larger than the inbound

MorphoSys: efficient colocation of QoS-constrained workloads in the cloud

In hosting environments such as IaaS clouds, desirable application performance is usually guaranteed through the use of Service Level Agreements (SLAs), which specify minimal fractions of resource capacities that must be allocated for unencumbered use for proper operation. Arbitrary colocation of applications with different SLAs on a single host may result in inefficient utilization of the host’s resources. In this paper, we propose that periodic resource allocation and consumption models -- often used to characterize real-time workloads -- be used for a more granular expression of SLAs. Our proposed SLA model has the salient feature that it exposes flexibilities that enable the infrastructure provider to safely transform SLAs from one form to another for the purpose of achieving more efficient colocation. Towards that goal, we present MORPHOSYS: a framework for a service that allows the manipulation of SLAs to enable efficient colocation of arbitrary workloads in a dynamic setting. We present results from extensive trace-driven simulations of colocated Video-on-Demand servers in a cloud setting. These results show that potentially-significant reduction in wasted resources (by as much as 60%) are possible using MORPHOSYS.National Science Foundation (0720604, 0735974, 0820138, 0952145, 1012798