Application-Level Unsupervised Outlier-Based Intrusion Detection and Prevention

Table 4

Instrumentation overhead versus increasing number of concurrent users.

Concurrent Users		5		10		15		20
Runs per User		120		60		40		30
Performance Indicator		ART [ms]	PMU [GB]	ART [ms]	PMU [GB]	ART [ms]	PMU [GB]	ART [ms]	PMU [GB]
Original (Noninstrumented) Apache OFBiz		142	3.05	210	3.88	303	3.98	400	4.15
Payment Module Instrumented; 6 intercepted calls per run x 600 runs = 3600 intercepted calls	Indicator Value	165	3.05	243	4.07	337	4.23	456	4.31
	Overhead (%)	16.20	0.00	15.71	4.90	11.22	6.28	14.00	3.86
	Average Overhead per Intercepted Call (%)	2.7	0.00	2.62	0.001	1.87	0.002	2.33	0.001
Invoice Module Instrumented; 48 intercepted calls per run x 600 runs = 28800 intercepted calls	Indicator Value	251	3.95	439	5.16	906	5.53	1056	5.62
	Overhead (%)	76.76	29.51	109.05	32.99	109.01	38.94	164.00	35.42
	Average Overhead per Intercepted Call (%)	1.6	0.001	2.27	0.001	2.27	0.001	3.42	0.001
Payment Module & Invoice Module Instrumented; 54 intercepted calls per run x 600 runs = 32400 intercepted calls	Indicator Value	268	4.11	480	5.22	908	5.66	1080	5.66
	Overhead (%)	88.73	34.75	128.57	34.54	199.67	42.21	170.00	36.39
	Average Overhead per Intercepted Call (%)	1.64	0.001	2.38	0.001	3.70	0.001	3.15	0.001