Architecture of Computing Systems (Lecture Notes in Computer ...

168 M.F. Dolz et al.
been submitted to each queue) and the users (as, e.g., the name, the user’s group,
the number of jobs submitted to each queue by this user, and the average waiting
and execution times of the jobs which have been submitted by this user).
Finally, the database records a history of the actions in each node (activations/deactivations),
the action timestamp, and the cause (e.g., if the node was
deactivated because a certain condition was satisfied).
3.4 Website Interface
The module has an interface that eases the administration of the energy saving
module. Possible operations using this website include:
– Check and modify configuration parameters of the energy saving system.
– Look up, delete, and modify users’ groups in the system.
– Look up and modify the parameters that define the activation/deactivation
policies of each group of users.
– Read the full database in HTML format, with the possibility to generate
reports (as PDF documents) with the required information.
– Monitor the operation of the cluster through a series of diagrams which illustrate
the active/inactive node times, the average waiting time and execution
time of jobs, etc.
– Monitor the energy savings in terms of power consumption and economic
cost.
– Set “active” bits for those nodes that the administrator will always keep
running, and declare unavailable nodes when they are crashed or being repaired.
– Turn on, reset or shut down the three daemons, and reset counters and timers
of the database.
All changes done on the system configuration parameters are updated both in
the database and the configuration files. Users without administrative privileges
can only view reports, diagrams, and configuration parameters.
4 Experimental Results
To evaluate the benefits of the system we have developed a flexible simulator,
named EnergySaving-SIM, that provides information on the system behavior for
various platform configurations and under realistic workloads. EnergySaving-
SIM applies the desired activation and deactivation policies to a given input
workload and can be easily adapted to reflect different types of platforms. Among
many other statistics, the simulator reports the percentage of the time that each
node in the cluster will be turned on/off and, therefore, offers an estimation of
the energy consumption.