Module XRay::DTrace::Tracer
In: lib/xray/dtrace/tracer/joyent.rb
lib/xray/dtrace/tracer/leopard.rb
lib/xray/dtrace/tracer.rb

Ruby module to fire application-level Dtrace events (using ruby-probe).

This module provide a convenient and unified API abstracting different tracing implementations in Leopard Ruby VM (by Apple) and in the one provided by Joyent (dev.joyent.com/projects/ruby-dtrace). This module also provides a NOOP implementation for Ruby VMs with no DTrace support: So you can use the exact same code while developing on Linux and deploying on Solaris for instance.

Methods

enabled?   fire   firing  

Classes and Modules

Module XRay::DTrace::Tracer::Joyent
Module XRay::DTrace::Tracer::Leopard

Public Instance methods

enabled?()

Returns true if ruby-probe probes are enabled. (application-level probes for Ruby).

[Source]

    # File lib/xray/dtrace/tracer.rb, line 66
66:       def enabled?
67:         false
68:       end
fire(name, data = nil)

Fire an application-level probe using ruby-probe.

The first argument passed will be passed to the D script as arg0 for the ruby-probe probe. This is conventionally a probe name.

The second argument is optional and can be used to pass additional data into the D script as arg1.

Example:

XRay::DTrace::Tracer.fire(‘service-start’, "order processing")

XRay::DTrace::Tracer.fire(‘service-stop’)

[Source]

    # File lib/xray/dtrace/tracer.rb, line 31
31:       def fire(name, data = nil)
32:       end
firing(name, data = nil) {|| ...}

Use ruby-probe to fire 2 application-level probes before and after evaling a block .

The first argument passed will be passed to the D script as arg0 for the ruby-probe probe. The first argument is conventionally a probe base name. The probes which fire before and after the block runs will have "-start" and "-end" appended to the probe base name, respectively.

The second argument is optional and can be used to pass additional data into the D script as arg1.

Example:

XRay::DTrace::Tracer.firing(‘db-query’, "select * from dual;") do 

  ActiveRecord::Base.execute("select * from dual;")

end

Will:

  1. Fire a probe with arg0 set to "db-query-start", and arg1 set to the sql query.
  2. Run the block and execute the SQL.
  3. Fire a probe with arg0 set to "db-query-start".

[Source]

    # File lib/xray/dtrace/tracer.rb, line 60
60:       def firing(name, data = nil)
61:         yield
62:       end

[Validate]