CDash:Design

Test Timing

Added since CDash 1.0. CDash supports timing defects for tests. CDash keeps in the database a current weighted average of the mean and standard deviation for each test time for each build. In order to keep the computation as light as a process as possible, the following formula is used, involving only the previous build.

 newMean = (1-alpha)*oldMean + alpha*currentTime
 newSD = sqrt((1-alpha)*SD*SD + alpha*(currentTime-newMean)* (currentTime-newMean)

A test is defined as failing if it verifies the following:

 if previousSD < thresholdSD then previousSD = thresholdSD.
 if  currentTime > previousMean*multiplier*previousSD.

One can notice that alpha defines the current “window” for the computation. By default alpha is set to 0.3.