Nowadays, the protection mechanisms are introduced into microservice
systems to ensure the stable operation of services. However, existing
approaches ignore the impact of protection mechanisms on the root cause
localization of abnormal services. Specifically, the circuit breaking
and rate limiting mechanisms can refuse service requests and thus change
the way of anomaly propagation. Moreover, different service request
frequencies and response time make service dependencies change
dynamically, resulting in different probabilities of anomaly propagation
among services. In this paper, we propose a novel framework named
MicroGBPM to locate the root cause of abnormal services, which considers
the impact of the protection mechanisms. We model anomaly propagation
among services as a dynamically constructed service attributed graph
with metrics and traces when a failure occurs. To eliminate the impact
of the protection mechanisms, we design a two-stage dynamic calibration
strategy to adjust the probability of anomaly propagation among
services. Then we propose a random walking approach to calculate the
root cause results by using the PageRank algorithm. The experimental
results show that MicroGBPM improves the accuracy of root cause
localization compared to other approaches in microservice systems with
protection mechanisms.