EVALUATION OF THE IMPACT OF JIT AND NATIVE AOT COMPILATION ON THE PERFORMANCE AND RESOURCE EFFICIENCY OF WEB SERVICES IN THE .NET 9 ENVIRONMENT

Abstract

This paper presents the findings of a study evaluating the impact of Just-In-Time (JIT) and Native Ahead-Of-Time (Native AOT) compilation techniques on the performance and resource efficiency of web services running in the .NET 9 environment. The relevance of the research is driven by the widespread adoption of containerized and serverless architectures, where reducing initialization time, increasing throughput, and optimizing system resource usage are critical requirements. The experimental study was conducted using a test web service developed with the ASP.NET Core platform and the lightweight WebApplication.CreateSlimBuilder() template. To minimize the overhead of third-party components, access to a local SQLite database was implemented via ADO.NET without using an ORM, and data serialization was handled using native System.Text.Json. The comparison evaluated two scenarios: single-record lookup by primary key and batch retrieval of 103 records followed by JSON serialization. Load testing was performed across a concurrency range of 1 to 200 parallel threads. The experimental results indicate that Native AOT provides a significant advantage during the cold start of the web service. The processing time for the initial request in the single-record lookup scenario dropped from approximately 668 ms for the JIT version to 44 ms for Native AOT, representing an nearly 15-fold decrease in latency. Throughput testing demonstrated that under a load of 4 parallel threads, Native AOT achieved approximately 667 req/s compared to 626 req/s for the JIT version. Memory analysis revealed comparable resource consumption in a stabilized state, with approximately 26.13 MB for JIT and 26.55 MB for Native AOT. The findings can be applied to inform the selection of compilation strategies when designing modern high-load web services.