State Reconciliation Defects in Infrastructure as Code

In infrastructure as code (IaC), state reconciliation is the process of querying and comparing the infrastructure state prior to changing the infrastructure. As state reconciliation is pivotal to manage IaC-based computing infrastructure at scale, defects related to state reconciliation can create large-scale consequences. A categorization of state reconciliation defects, i.e., defects related to state reconciliation, can aid in understanding the nature of state reconciliation defects. We conduct an empirical study with 5,110 state reconciliation defects where we apply qualitative analysis to categorize state reconciliation defects. From the identified defect categories, we derive heuristics to design prompts for a large language model (LLM), which in turn are used for validation of state reconciliation. From our empirical study, we identify 8 categories of state reconciliation defects, amongst which 3 have not been reported for previously-studied software systems. The most frequently occurring defect category is inventory, i.e., the category of defects that occur when managing infrastructure inventory. Using an LLM with heuristics-based paragraph style prompts, we identify 9 previously unknown state reconciliation defects of which 7 have been accepted as valid defects, and 4 have already been fixed. Based on our findings, we conclude the paper by providing a set of recommendations for researchers and practitioners.