In late 2020, a leading technology company was awarded a high-profile contract to provide a portal for the NHS that allowed eligible UK citizens to book a vaccination appointment at a convenient location and time.
The solution was driven via a REST API, with a custom .NET web frontend.
Prolifics Testing was engaged to carry out a performance test to ensure that the integrated solution worked as expected, and could support the anticipated high volumes of users and transactions, before go-live.
A key set of user journeys were identified, including users entering a valid invitation code and proceeding to make an appointment, as well as a series of use cases that simulated users hitting refresh on multiple occasions and entering invalid invitation codes. Our JMeter instance in the AWS cloud was used to record a set of parameterised performance scripts, which were then grouped to form overall test scenarios to be run against a defined data set.
The testing process
The tests were executed against a Cloud platform, consisting of a load balanced set of five front-end IIS web servers, accessing a single SQL Server. A number of iterations were necessary to implement code changes with a view to optimising performance. This was also necessary to implement infrastructure changes, which helped to increase the level of possible throughput and remove bottlenecks.
We worked with the project team to gather resource statistics throughout the tests and verify that all records had been correctly populated to the backend. After several iterations, a throughput of 2500 users were simulated on the portal, resulting in 300,000 simulated vaccination bookings across a one-hour period.
This provided us and the client with the necessary confidence that the portal could be made live. If these tests had not been carried out and the system performance was left to chance, these problems would likely have made it into production, with obvious reputational damage for both the NHS, and their suppliers.