Module: XRay::DTrace::Tracer

Defined in:
lib/xray/dtrace/tracer.rb,
lib/xray/dtrace/tracer/joyent.rb,
lib/xray/dtrace/tracer/leopard.rb

Overview

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.

Defined Under Namespace

Modules: Joyent, Leopard

Instance Method Summary collapse

Instance Method Details

#enabled? ⇒ Boolean

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

Returns:

  • (Boolean) 


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# File 'lib/xray/dtrace/tracer.rb', line 66

def enabled?
  false
end

#fire(name, data = nil) ⇒ Object

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’)



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# File 'lib/xray/dtrace/tracer.rb', line 31

def fire(name, data = nil)
end

#firing(name, data = nil) ⇒ Object

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”.



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# File 'lib/xray/dtrace/tracer.rb', line 60

def firing(name, data = nil)
  yield
end