TuningFork Binary Format Specification

TuningFork supports the analysis and visualization of one or more feeds of events. The feeds may either be read from a file (off-line mode) or received over a socket connection (on-line mode). Both modes use the binary feed format which is specified here.

Feeds and Feedlets

A feed contains feed meta-data and an interleaving of meta-data and data from one or more feedlets. A feedlet is a logical event-generating entity in the application being traced. For example, in a feed from a JVM, each Java and VM thread would be a feedlet. Or, if the feed is tracing OS operations on an SMP machines, it would probably make sense to represent each CPU as a feedlet.

A feed starts with a header and is followed by a sequence of chunks. All feeds must start with a feed header, followed by meta-data chunks as required by the application being traced. The bulk of the feed will consist of data chunks, but the format specification allows feed meta-data and data chunks to be intermingled.