trace enables tracing of an application. It exposes the following command line interface (invoke trace with --help to get an overview):
trace [options] command [command-specific options] --help: Produce this help message list-categories - list all known categories record - starts tracing and records data --[command args]: Run program before starting trace. The program is terminated when tracing ends unless --detach is specified --append-args=[""]: Additional args for the app being traced, appended to those from the spec file, if any --buffer-size=: Maximum size of trace buffer for each provider in megabytes --provider-buffer-size=[provider-name:buffer-size]: Specify the buffer size that "provider-name" will use. May be specified multiple times, once per provider. --buffering-mode=[oneshot]: Specify buffering mode as one of oneshot, circular, or streaming --categories=[""]: Categories that should be enabled for tracing --decouple=[false]: Don't stop tracing when the traced program exits --detach=[false]: Don't stop the traced program when tracing finished --spawn=[false]: Use fdio_spawn to run a legacy app. Detach will have no effect when using this option. --environment-name=[none]: Create a nested environment with the given name and run the app being traced under it. --return-child-result=[true]: Pass on the child's return code. --duration=: Trace will be active for this many seconds after the session has been started. The provided value must be integral. --output-file=[/data/trace.json]: Trace data is stored in this file The output file may be "tcp:IP-ADDRESS:PORT" in which case a stream socket is connected to that address and trace data is streamed directly to it instead of saving the output locally. Streaming via TCP is generally only done when invoked by traceutil. --compress=[false]: Compress the output stream. Compressing a network output stream is not supported, if both --output-file=tcp:... and --compress are provided, --compress is ignored. --spec-file=[none]: Tracing specification file
Options provided on the command line override options found in the
--spec-file spec file.