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 ...

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