LASS: Reducing Cold Startup Latency in Serverless Through Loaded Library Sharing

In serverless scenario, function invocation runs in an individual container. Lightweight container technology has significantly reduced the startup latency of container. The library loading process now becomes a critical performance bottleneck of serverless function cold startup. The state-of-the-art approaches leverage the process fork operation to reduce the cold startup latency in serverless computing by reusing the loaded libraries. However, the fork operation can only share libraries between parent process and forked process. For security, the libraries loaded by the parent process should be a subset of those required by the forked process, which limits opportunities to eliminate library loading overhead. To address this problem, we propose theLASSsystem, which enables multiple processes to share initialized libraries in a composable and efficient manner.LASSallows a process to securely reuse libraries loaded by multiple processes, thereby reducing library loading latency to the millisecond level. Compared to the state-of-the-art approaches,LASScan improve average library loading speed by more than 10.3×, and reduce 99thpercentile end-to-end latency by 34%–57%.