Manual: pythonflow-bpfcc

uflow(8)				   System Manager's Manual				    uflow(8)

NAME
       uflow,  javaflow,  perlflow,  phpflow,  pythonflow,  rubyflow, tclflow - Print a flow graph of method
       calls in high-level languages.

SYNOPSIS
       javaflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       perlflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       phpflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       pythonflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       rubyflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       tclflow [-h] [-M METHOD] [-C CLAZZ] [-v] pid
       uflow [-h] [-M METHOD] [-C CLAZZ] [-v] [-l {java,perl,php,python,ruby,tcl}] pid

DESCRIPTION
       uflow traces method calls and prints them in a flow graph that can facilitate debugging and  diagnos‐
       tics by following the program's execution (method flow).

       This  tool  relies  on  USDT  probes  embedded in many high-level languages, such as Java, Perl, PHP,
       Python, Ruby, and Tcl. It requires a runtime instrumented with these probes, which in some cases	 re‐
       quires  building from source with a USDT-specific flag, such as "--enable-dtrace" or "--with-dtrace".
       For Java processes, the startup flag "-XX:+ExtendedDTraceProbes" is required. For PHP processes,	 the
       environment variable USE_ZEND_DTRACE must be set to 1.

       Since this uses BPF, only the root user can use this tool.

REQUIREMENTS
       CONFIG_BPF and bcc.

OPTIONS
       -M METHOD
	      Print only method calls where the method name begins with this string.

       -C CLAZZ
	      Print only method calls where the class name begins with this string. The class name interpre‐
	      tation  strongly	depends on the language. For example, in Java use "package/subpackage/Class‐
	      Name" to refer to classes.

       -v     Print the resulting BPF program, for debugging purposes.

       {java,perl,php,python,ruby,tcl}
	      The language to trace.

       pid    The process id to trace.

EXAMPLES
       Follow method flow in a Ruby process:
	      # uflow ruby 148

       Follow method flow in a Java process where the class name is java.lang.Thread:
	      # uflow -C java/lang/Thread java 1802

FIELDS
       CPU    The CPU number on which the method was invoked. This is useful to easily see where the  output
	      skips to a different CPU.

       PID    The process id.

       TID    The thread id.

       TIME   The duration of the method call.

       METHOD The method name.

OVERHEAD
       This  tool  has	extremely high overhead because it prints every method call. For some scenarios, you
       might see lost samples in the output as the tool is unable to keep up with the rate  of	data  coming
       from  the kernel. Filtering by class or method prefix can help reduce the amount of data printed, but
       there is still a very high overhead in the collection mechanism. Do not use for	performance-  sensi‐
       tive production scenarios, and always test first.

SOURCE
       This is from bcc.

	      https://github.com/iovisor/bcc

       Also look in the bcc distribution for a companion _example.txt file containing example usage, output,
       and commentary for this tool.

OS
       Linux

STABILITY
       Unstable - in development.

AUTHOR
       Sasha Goldshtein

SEE ALSO
       trace(8), ustat(8)

USER COMMANDS					 2018-10-09					    uflow(8)