Estimating waiting time at a server
The enclosed trace shows the requests received at a Web-server. Use the arrival times
and the file sizes in the trace file as input to a simulator, as explained below.
1. Modify the M/M/1 simulator to a trace–driven simulator such that it reads the arrival times and file sizes
from the trace file (or a reorganized version of it)***
2. Now, assume that the service time needed by the server for each request is:
Service-Time-in-seconds = 0.1 +
0.6 * Size-in-kilobytes.
and calculate following measures using the first 5000 requests in the trace:
· The maximum queue length at the server
· The maximum delay in the queue
· The average time spent by a customer (a request is equivalent to a customer) in the queue
· Number of customers waiting more than 0.5 second in the queue
.
3. Now, calculate the same measures as in 2 (using the same 5000 requests),
4. but for a faster server with the following service time
Service-Time-in-seconds = 0.1 +
0.3 * Size-in-kilobytes
5. Repeat part 3 and 4, but with the next 5000 requests in the trace and compare the obtained results.
6. Prepare a written report (not more than 10 pages) describing your experiments, obtained results , your analysis and your conclusion.
7.
Include
a section in your report explaining participation of each group member in the
project (who did what), what you learned from the project and how the project
can be improved.
8.
Write
name and email of all group members on the first page of your report
9.
Save your
report in a SINGLE file in pdf format and send it by email to the course assistant.
The subject of your email should be 2g1126-your-group-no
*** For source code of the M/M/1 and some additional info see project web-page