83 lines
2.7 KiB
Go
83 lines
2.7 KiB
Go
/*
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Constants that are used across scripts
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1. The available hosts = stratos-00x (x varies from 1 to 8)
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2. cap_margin = percentage of the requested power to allocate
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3. power_threshold = overloading factor
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4. total_power = total power per node
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5. window_size = number of tasks to consider for computation of the dynamic cap.
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Also, exposing functions to update or initialize some of the constants.
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*/
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package constants
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var Hosts = []string{"stratos-001.cs.binghamton.edu", "stratos-002.cs.binghamton.edu",
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"stratos-003.cs.binghamton.edu", "stratos-004.cs.binghamton.edu",
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"stratos-005.cs.binghamton.edu", "stratos-006.cs.binghamton.edu",
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"stratos-007.cs.binghamton.edu", "stratos-008.cs.binghamton.edu"}
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// Add a new host to the slice of hosts.
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func AddNewHost(newHost string) bool {
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// Validation
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if newHost == "" {
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return false
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} else {
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Hosts = append(Hosts, newHost)
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return true
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}
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}
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/*
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Lower bound of the percentage of requested power, that can be allocated to a task.
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Note: This constant is not used for the proactive cluster wide capping schemes.
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*/
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var PowerThreshold = 0.6 // Right now saying that a task will never be given lesser than 60% of the power it requested.
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/*
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Margin with respect to the required power for a job.
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So, if power required = 10W, the node would be capped to 75%*10W.
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This value can be changed upon convenience.
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*/
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var CapMargin = 0.70
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// Modify the cap margin.
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func UpdateCapMargin(newCapMargin float64) bool {
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// Checking if the new_cap_margin is less than the power threshold.
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if newCapMargin < StarvationFactor {
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return false
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} else {
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CapMargin = newCapMargin
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return true
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}
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}
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/*
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The factor, that when multiplied with (task.Watts * CapMargin) results in (task.Watts * PowerThreshold).
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This is used to check whether available power, for a host in an offer, is not less than (PowerThreshold * task.Watts),
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which is assumed to result in starvation of the task.
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Here is an example,
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Suppose a task requires 100W of power. Assuming CapMargin = 0.75 and PowerThreshold = 0.6.
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So, the assumed allocated watts is 75W.
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Now, when we get an offer, we need to check whether the available power, for the host in that offer, is
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not less than 60% (the PowerTreshold) of the requested power (100W).
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To put it in other words,
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availablePower >= 100W * 0.75 * X
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where X is the StarvationFactor (80% in this case)
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Note: This constant is not used for the proactive cluster wide capping schemes.
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*/
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var StarvationFactor = PowerThreshold / CapMargin
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// Window size for running average
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var WindowSize = 160
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// Update the window size.
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func UpdateWindowSize(newWindowSize int) bool {
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// Validation
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if newWindowSize == 0 {
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return false
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} else {
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WindowSize = newWindowSize
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return true
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}
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}
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