7. Application-Level Protocols

This chapter is a continuation of Chapter 6, Network Lower-Level Protocols, and covers several common application-level network protocols, including HTTP and Network File System (NFS). Using DTrace, you can answer questions about application protocols such as the following.

• What NFS clients are performing the most I/O?

• What files are NFS clients performing I/O to?

• What is the latency for HTTP requests?

These can be answered with DTrace. As an example, nfsv3rwsnoop.d is a DTrace-based tool to trace NFSv3 reads and writes on the NFS server, showing the client and I/O details:

image

Although network sniffing tools can ...

Get The Official Ubuntu Server Book, 3rd Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.