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Advances, Systems and Applications

Journal of Cloud Computing Cover Image

Table 1 Summary of VM provisioning concepts and their notation

From: Prediction-based VM provisioning and admission control for multi-tier web applications

A(k) set of web applications at time k
A i (k) set of inactive applications at time k
A li (k) set of long-term inactive applications at time k
A over (k) set of overloaded applications at time k
S(k) set of servers at time k
S lu (k) set of long-term underutilized servers at time k
S n (k) set of new servers at time k
S over (k) set of overloaded servers at time k
S ¬o v e r (k) set of non-overloaded servers at time k
S t (k) set of servers selected for termination at time k
S u (k) set of underutilized servers at time k
C(a,k) measured CPU utilization of application a at time k
C(s,k) measured load average of server s at time k
\(\hat {C}(s,k)\) predicted load average of server s at time k
C w (s,k) weighted load average of server s at time k
d e p_a p p s(s,k) applications deployed on server s at time k
i n a c t i v e_c(a) inactivity count of application a
M(a,k) measured memory utilization of application a at time k
M(s,k) measured memory utilization of server s at time k
\(\hat {M}(s,k)\) predicted memory utilization of server s at time k
M w (s,k) weighted memory utilization of server s at time k
u n d e r_u_c(s) underutilization count of server s
W(s,k) weight of server s at time k for load balancing
A A aggressiveness factor for additional capacity
A P aggressiveness factor for VM provisioning
A T aggressiveness factor for VM termination
P P (k) proportional factor for VM provisioning
D P (k) derivative factor for VM provisioning
P T (k) proportional factor for VM termination
D T (k) derivative factor for VM termination
w c weighting coefficient for CPU load average
w m weighting coefficient for memory usage
w p weighting coefficient for VM provisioning
w t weighting coefficient for VM termination
C L A application CPU utilization lower threshold
C L S server load average lower threshold
C U A application CPU utilization upper threshold
C U S server load average upper threshold
I C T A inactivity count threshold for an application
I C T S inactivity count threshold for a server
M L A application memory utilization lower threshold
M L S server memory utilization lower threshold
M U A application memory utilization upper threshold
M U S server memory utilization upper threshold
W MAX maximum value of a server weight for load balancing
N A (k) number of additional servers at time k
N B number of servers to use as base capacity
N P (k) number of servers to provision at time k
N T (k) number of servers to terminate at time k