Function Placement Approaches in Serverless Computing: A Survey

Serverless computing is a new paradigm computing in cloud computing that allows developers to focus on code development without the need to manage infrastructure and enjoy the benefits of automatic scaling and low costs. The function placement mechanism is a critical concept in serverless computing that refers to choosing the optimal place for executing functions to improve the efficiency of resources and reduce the delay in executing functions. However, this process faces challenges such as the complexity of dynamic environments, heterogeneous resources, variable execution costs, and changes in the timing of requests, which make it challenging to choose the appropriate location for functions. This article provides a comprehensive overview of function placement mechanisms in serverless computing. It aims to introduce a comprehensive and systematic classification of critical approaches such as machine learning (ML)-based, heuristic-based, and model-based that are used in implementing function placement. Also, by examining each approach's strengths and weaknesses, this review article helps researchers and developers find a better perspective on the existing solutions and approaches and avoid repeated efforts by comprehensively reviewing previous research. In addition, by identifying research gaps and introducing new paths, this research provides the basis for improving future research.