Data Loss

The statistics to measure the response to data losses tracks the duplicate requests (and repairs), and the average request (and repair) delay. The algorithm used is documented in Floyd [11]. In this algorithm, each new request (or repair) starts a new request (or repair) period. During the request (or repair) period, the agent measures the number of first round duplicate requests (or repairs) until the round terminates either due to receiving a request (or repair), or due to the agent sending one. The following code illustrates how the user can simple retrieve the current values in an agent:
                set statsList [$srm array get statistics_]
                array set statsArray [$srm array get statistics_]
The first form returns a list of key-value pairs. The second form loads the list into the statsArray for further manipulation. The keys of the array are dup-req, ave-dup-req, req-delay, ave-req-delay, dup-rep, ave-dup-rep, rep-delay, and ave-rep-delay.

Tom Henderson 2011-11-05