CLOUD COMPUTING: ESTIMATION OF EXECUTION DURATION PERTINENT TO CONCURRENT EXECUTION OF THREADS

摘要

Platform as a Service (PAAS) in Cloud Computing can be utilized to executeApplication toprocess data. Sequential processing of data starts by reading a chunk of datafrom a CloudRepository, proceeding by executing functions on chunk of data, and ends bywriting results to aCloud Repository. Dividing the code block of sequential instructions andfunctions for processingof data into sections yields step 0, step 1,...,step n-2, step n-1 dubbed StepSequence. The stepsare ordered by ascending index. step 0 fetches a chunk of data from a CloudRepository. step n-1stores the output of the preceding step in a Cloud Repository. step i, 1= i = n - 2 executesfunctions on the output of preceding step.Each step can be executed in a thread: step 0 yields thread of type Input(thread 0), step n-1 yieldsthread of type Storing (thread n-1), step i, 1= i = n - 2 yieldsthread of type Compute (thread i),and if the next step of step i, 0 = i = n - 2 is executed inalternative Instance, the step yields athread of type Transport (transThread i) in addition to thread i.Threads of Step Sequence can be executed in sequence in single Instance or canbe distributedto a number of Instances for executing. In occurrence of executing a number ofStep Sequences,threads of Step Sequences can be executed concurrently in groups. Executionduration of a groupof threads executed concurrently can be estimated utilizing a quadraticequation: a(Metric 1)2 +bxMetric 1 + c + d(Metric 2)2 + exMetric 2 + f .Known values of the quadratic equation are calculated utilizing regressionanalysis to relate:.cndot. A metric to execution duration of single thread..cndot. A number of metrics to execution &gallon of concurrent execution ofthreads.The quadratic equation for estimating execution duration of concurrentexecuting of threads hasapplication in estimating duration of processing data accomplishing by a StepSequence, scalingthreads of Step Sequences on a number of Instances for execution, scalingInstances of the CloudServer executing threads of Step Sequences, and defining a quality of servicepertinent toexecution duration of Step Sequence.