# The FaaS-Based Cloud Agnostic Architecture of Medical Services--Polish Case Study
## 4 Results
### Results For Experiments with Continuous and Variable Load Profile
All this indicates certain advantages of the FaaS solution over the classic one. Figure 4: Statistics for times of request executions for FaaS solution (**a**) and classic one (**b**). Figure 5: Histograms describing distributions of times of request executions (response times) for FaaS solution (**a**) and classic one (**b**). Empirically, we found the throughput limit defined as the maximum value of Cnt/s under two assumed constraints (the value of the 95 th quantile of response times should be less than or equal to 200 ms and the fraction of successful responses should be equal to or greater than 95). For this purpose, we used the load range defined by the values of NoR\({}_{max}\) = 50, 60, 100 reqs/s. The resulting throughput limit for the classic version was 20 requests per second. For the considered load range, the two mentioned limits were always met for the FaaS variant (the limit was not reached). This makes the FaaS variant superior in terms of throughput limit. Further observations about the courses of memory allocation are particularly important in terms of cost. Sample courses of SML(\(t\)) during a one-hour interval for the FaaS solution and the classic one are presented in Figures 6 and 7. All courses were rendered using the user interface Grafana's ([[https://grafana.com](https://grafana.com)]([https://grafana.com](https://grafana.com)), accessed on 17 May 2022) monitoring tool, which visualizes the monitoring data collected by Prometheus ([[https://prometheus.io](https://prometheus.io)]([https://prometheus.io](https://prometheus.io)), accessed on 17 May 2022). According to the knowledge about the memory limits (classic--1 GB ; FaaS--64 MB) we can observe:  
* When the system is not under load (for example, when \(0<t<t_{1}\)): two _Pods_ are instantiated by the classic solution (2 GB of SML / 1 GB of memory limit = two instances);  
Figure 6: Sample course of sum of memory limits (SML) for FaaS solution during the one-hour experiment. Figure 7: Sample course of sum of memory limits (SML) for classic solution during the one-hour experiment. When the system is not under load: zero _Pods_ are instantiated by the FaaS solution;
* When the system is under maximal load (for example, when \(t_{2}<t<t_{3}\)): SML equals 10 GB for the classic solution;
* When the system is under maximal load: 10 _Pods_ are instantiated by the classic solution (10 GB of SML/ 1 GB of limit = 10 instances). HPA is in a saturated state--the maximum number of _Pods_ for the classic solution is achieved,
* When the system is under maximal load: SML equals only 704 MB for the FaaS solution;
* When the system is under maximal load: 11 _Pods_ are instantiated by the FaaS solution (704 MB of SML / 64 MB of limit = 11 instances), which is a significantly smaller value than 160--the maximum number of _Pods_ for HPA for the FaaS solution. The final cost evaluation was based on the values of the quality indicator (OI) for the experiment lasting \(T_{max}=10\) h. The QI for the classic solution equaled 5944.3 MB. The QI for the FaaS solution equaled 264.9 MB which is a significant improvement (QI 22.5 times smaller) compared to the QI of the classic solution.