Estimated Interval-Based Checkpointing (EIC) on Spot Instances in Cloud Computing

Algorithm 1

Checkpointing and recovery algorithm.

(1)   // Input: user’s requested task and bid

(2)   // Output: total task execution time and total cost

(3)  Boolean   𝐹_flag = false // a flag representing occurrence of a task failure

(4)   Boolean EI_flag = true // a EI_flag representing a task start

(5)   while (! Task execution finishes) do

(6)    if (EI_flag) then

(7)     Estimation( );

(8)     EI_flag = false;

(9)    end if

(10)  if (spot prices < User bid) then

(11)   if (𝐹_flag) then

(12)    Recovery( );

(13)    𝐹_flag = false;

(14)   end if

(15)   if (rising edge && Price threshold < spot prices) then

(16)   Checkpoint( );

(17)   end if

(18)   if (Time threshold < execution time in current price) then

(19)   Checkpoint( );

(20)   end if

(21)  end if

(22)  if (failure is occurred) then

(23)   𝐹_flag = true;

(24)  end if

(25) end while

(26) Function Estimation( )

(27)  calculate the points of checkpoint to base a price history;

(28)  set the price and time thresholds;

(29) end Function

(30) Function Checkpoint( )

(31)  task a checkpoint on the spot instance;

(32)  Send the checkpoint to the storage;

(33) end Function

(34) Function Recovery( )

(35)  retrieve the checkpoint information form the storage;

(36)  restart the job execution;

(37) end Function