Introduction
Our backup application, which runs over an NFS (Network File System) mount, is designed for high performance. While developing our backup solution, we found we had to implement our own NFS client (in user space): By using our own client, we are able to fine-tune the load that the application imposes on any given server; we adapt to slow servers by backing off and to fast servers by increasing the load. Additionally, our client can list enormous directories (often with many millions of entries) piecemeal in a way that overwhelms neither client nor server.
In some ways, the NFS protocol is just another encoding. There are already many encoding packages in Go (json, xml, etc.) and like those, our team used Go’s reflection facility to get going as fast as possible. Quickly, we found reflection was the bottleneck to higher performance.