Event Filters

class performance.driver.core.eventfilters.EventFilter(expression)

Various trackers in DC/OS Performance Test Driver are operating purely on events. Therefore it’s some times needed to use a more elaborate selector in order to filter the correct events.

The following filter expression is currently supported and are closely modeled around the CSS syntax:

EventName[attrib1=value,attrib2=value,...]:selector1:selector2:...

Where:

• _Event Name_ is the name of the event or * if you want to match any event.

• _Attributes_ is a comma-separated list of <attrib> <operator> <value> values. For example: method==post. The following table summarises the different operators you can use for the attributes.

  Operator	Description
  = or ==	Equal (case sensitive for strings)
  !=	Not equal
  >, >=	Grater than / Grater than or equal
  <, <=	Less than / Less than or equal
  ~=	Partial regular expression match
  ~==	Exact regular expression match
  <~	Value in list or key in dictionary (like in)

• _Selector_ specifies which event out of many similar to chose. Valid selectors are:

  Selector	Description
  :first	Match the first event in the tracking session
  :last	Match the last event in the tracking session
  :nth(n) :nth(n,grp)	Match the n-th event in the tracking session. If a grp parameter is specified, the counter will be groupped with the given indicator.
  :single	Match a single event, globally. After the first match all other usages accept by default.
  :after(Xs)	Trigger after X seconds after the last event
  :notrace	Ignore the trace ID matching and accept any event, even if they do not belong in the trace session.

For example, to match every HTTPRequestEvent:

HTTPRequestEvent

Or, to match every POST HTTPRequestEvent:

HTTPRequestEvent[method=post]

Or, to match the last HTTPResponseEndEvent

HTTPResponseEndEvent:last

Or, to match the HTTPRequestStartEvent that contains the string “foo”:

HTTPResponseEndEvent[body~=foo]

Or match any first event:

*:first