PE average response times

Edit online

For considering the PE average response times across the different CE/PE guest CPU scenarios a single average response time for all individual PE transaction types has been calculated.

This value is an arithmetic mean across all PE operation categories (Query / Reassign / Update / Dispatch / Launch / Logon). The next chart shows these overall average response times for the CPU scenarios in relation to their throughput levels.

Figure 1. Non-weighted average response times for PE operations in relation to the throughput numbers and CPUs used
Line graph showing PE average response times for normalized throughput

Observations

For this particular workload using direct Java API calls, response times below 200 milliseconds are expected and good. The average response times measured are stable and low over most of the workload range. At the very highest workload level, as the CE/PE guest CPUs near maximum utilization, API response times also start to increase (while remaining well below 1 second).

Similarly to the CE response times, the PE average response times remain low until a certain CPU usage level is reached (usually above 80% CPU load). Adding more CPUs for these workload levels takes the response times down again and allows further throughput increase.

The amount of CPUs on the database system has a minor role, two were sufficient for all scenarios, for the lowest workload levels with one CE/PE CPU only one CPU was sufficient.