Performance testing parameters and its relation with performance

1.     Response time (Total turnaround time (TTAT))

• Always measured in seconds on client side, measured in millisecond for server processing, measured in nanosecond for network.
• Response time is inversely proportional to performance.

2.     Hit per second (HPS)

• Request accepted by server, not processed by server
• It is directly proportional to efficiency of server which might yield to higher performance.

           Case 1:- load is increasing but hit is not increasing -> client side memory leaks,

           Example: IE GUI closed but process running,

           Case 2:- load is in steady state but hit/sec is zero => hits are in queue

3. Throughput

• For response data, it is measured in bytes per sec. It helps us in analysing the bandwidth, how much data is processed and pushed from server to client.
• Case1: Hit/sec is decreased, load is increased but throughput is increasing -> memory leak at server side. Unclosed, unattended session at server. Improper handling of sessions.
• Throughput increases with increasing hits on the web server for a certain range. Generally, it also depends on the bandwidth available. Then at a certain range, the Throughput becomes constant & at this point if hits per sec increases then the throughput decreases.
• So whenever we derive a relation between Hits per sec & Throughput then within the threshold limits they are directly proportional to each other.

4. Transaction per sec (TPS)

• Number of transaction of a specific business process has been completed in one second, larger the value higher the efficiency of server and higher the performance.

5. Total transaction per second (TTPS)

• Total no of transactions completed in one second irrespective of business process. Larger the value of TTPS, higher the efficiency of server.

6. Connection per second (CPS)

• Number of connection opened per second
• The number of new connections should be a small fraction of the number of hits per second, because new TCP/IP connections are very expensive in terms of server, router and network resource consumption. Ideally, many HTTP requests should use the same connection, instead of opening a new connection for each request.
• Exponential directly proportional to load

7. Pages downloaded per second (PDPS)

• Number of Web pages downloaded from the server during each second of the load test scenario run.