Cost-Effective Resource Provisioning for Real-Time Workflow in Cloud

Algorithm 4

Dynamic programming knapsack algorithm.

(1)	procedure (DPK(TW, VMs, D))
(2)	if D × P1 < TW then
(3)	return Failure;
(4)	else
(5)	m ⟵ the number of VMs;
(6)	TW1 ⟵ TW;
(7)	x1 ⟵ ⌈TW1/P1⌉;
(8)	f1 ⟵ x1 × PRICE1;
(9)	for j = 2 to m do
(10)	TWj ⟵ TWj−1 − (xj−1 − 1) × Pj−1;
(11)	xj ⟵ ⌈TWj/Pj⌉;
(12)	fj ⟵ fj−1 − PRICEj−1 + xj × PRICEj;
(13)	if fj ≥ fj−1 or xj−1 − 1 + TWj/Pj > D then;
(14)	fj ⟵ fj−1;
(15)	xj ⟵ 0;
(16)	else
(17)	xj−1 ⟵ xj−1 − 1;
(18)	end if
(19)	end for
(20)	return X;
(21)	end if
(22)	end procedure