1. Thermal Management of Heterogeneous Data Centers
David Bendit
System Administrator
Mars Space Flight Facility
Arizona State University

2. Introduction Mars Space Flight Facility
Located in the Moeur Building (West of the MU)
Medium-sized server room
Roughly 12’x25’
Over 100 physical servers
Small cluster
26 physical machines, each running 4 Xen instances
Total of 104 nodes optimally

3. Motivation Chiller had a bad habit of dying over weekends
Come in Monday morning to a 90°F+ server room
IMPACT research has studied the HPCI Cluster
HCPI is more homogenous, dedicated to cluster processing
Proper cooling setup
More standard layout
MSFF server room is sub-optimal setup, which doesn’t have as much research

4. Problem Statement
What qualities are important in selecting a thermal-aware job scheduling algorithm for heterogeneous data centers
Based on those qualities, which algorithms fare the best
How does the heterogeneity of the data center affect the performance of the algorithms chosen?

5. Approach Physical Virtual
Temperature sensors throughout the server room
Wireless, single-hop sensor network
Logging of cluster jobs and as many physical server temps as feasible
Virtual
Simulation of various scheduling strategies using FloVENT
Will take into account server room layout and air flow

6. Difficulties Physical
Originally supposed to work with another team to create temperature sensor network
My contact in that team ended up dropping the class
Logging cluster job traces
Limited experience with new scheduling software at MSFF
Logging individual server temperatures
Heterogeneity of hardware means that not all supports reporting temperatures over SNMP or other means

7. Difficulties, cont. Virtual Server room floor plans
We’ve placed things around where they fit, without more pre-planning than general ideas
Needed to create this, and left out important details (namely, air vents and the like)
Simulation software
License is expired and needs to be renewed before any simulations can be run

8. Difficulties, cont. General MSFF is NASA funded
As a US Government facility, we’re not able to let foreign nationals into the server room
Frequent changes to the server room itself
As data storage requirements, etc. change, we change equipment, so things can change week-to-week
Results may not be implementable
Because of very specific user requirements, useful changes may not be implemented anyway

9. Moving Forward Project will continue past the length of this course
We will correlate cluster activity with machine and ambient temperatures
End goal
Reduce overall strain on the chiller
My (rather pessimistic) prediction
Because of large number of other computing resources in the server room, and always-on nature of our setup, cluster has negligible impact on overall temperature
Need more wide-ranging changes for real temperature reduction

10. Questions?