1. A method for recommending a suspicious component in problem diagnosis for a cloud application, comprising: constructing a graph data model representing a hierarchical structure of the cloud application, wherein the graph data model comprises an application node representing the cloud application, a plurality of component nodes representing a plurality of components of the cloud application, and inter-node lines indicating inter-node relationships; obtaining real-time information of the cloud application, in response to detecting performance degradation of the cloud application; obtaining impact degrees of the plurality of component nodes on the performance degradation of the cloud application, based on the graph data model and the real-time information; and generating a suspicious component sequence, according to the impact degrees of the plurality of component nodes.