1. CSE598C Project: Dynamic virtual server placement Yoojin Hong

2. Mobile VM servers (From the vMatrix) Static mirroring vs. Mobile virtual machine servers

3. Mobile VM servers Basic ideas  VM servers can be hosted in any real machines across networks  VM servers can be instantiated on demand  VM servers can move closer to end users Advantages of mobile virtual machine servers  Higher availability  Better response time  Absorbing flash crowds  Network bandwidth savings  Lower cost of ownership of server machines

4. Mobile VM servers Two-tier architectures

5. Mobile VM servers Disadvantages of mobile virtual machine servers  Difficulty to virtualize large size of database server Closer front-end VM server is beneficial only when # of packets via connection A is larger than that via connection B  Overhead of migrating OS and applications for VM servers FRONT END BACK END Connection AConnection B

6. Scenarios The service is provided mainly by compute- intensive application server Locations of majority of end users are changing  Suppose users of CNN.com has an access pattern to visit the site around 4-5p.m.  Time difference between east coast and west coast

7. Problem description Dynamic provisioning + Placement of web server replicas Problems  Determine when a new VM server needs to be added (When) Change of locations of end users  Select a real machine, which is located in an optimal location from end users, to host the new VM server (How) Location of real machines available Location of end users Location of back-end server relative to real machines Size of VM files relative to size of server requests Cost of bandwidth during different times of day Location of real machines to host VM servers currently

8. Algorithms When  When locations of end users are changing # of users located where current server cannot guarantee a certain response time is increasing

9. Algorithms How – Modified k-mean algorithm  1. Find k number of centroids at random  2. Assign each end user location to its closest centroid  3. Update the centroids as follows: : # of end user locations assigned to cluster j : location of end user j : application-specific constant weight ( 0) B : location of back-end server  4. Repeat 2, 3 steps until the centroids are converged  5. Select RMs located closest to the centroids

10. Experiments Simulation Comparison …