Defining measures for WMS and VOMS services evaluation Sergio Andreozzi INFN-CNAF JRA1 IT/CZ meeting, 10 november 2005

WMS-related measurers review VOMS-related measurers review OUTLINE Facts Why measuring What is a measure Basics of measurement theory Document structure WMS-related measurers review VOMS-related measurers review EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

Facts See SA1 Metric WG wiki are meaningful are correct During the last EGEE Operations workshop (Sep05), SA1 created a Metric WG for the definition of a set of metrics useful to evaluate, functionality and performance of the EGEE Grid It is a mixed approach where both passive and active monitoring are in place There is a fast push to have something in place “now” It is vital to enter the definition process in order to be sure that the defined metrics are meaningful are correct can be measured See SA1 Metric WG wiki http://goc.grid.sinica.edu.tw/gocwiki/Service_Metrics EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

Why Measuring measurement Numerical objects, Real-world objects, relationships and operationts Real-world objects, relationships and operationts Intelligence barrier mathematics, statistics Results relevant to the world Numerical results interpretation EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

What is a Measure Measurement: the process by which numbers or symbols are assigned to attributes of entities in the real world in such a way as to describe them according to clearly defined rules. Measure: Let A be a set of physical or empirical objects. Let B be a set of formal objects, such as numbers. A measure μ is defined to be a one-to-one mapping μ : A B. Measurement Method: logical sequence of operations, described generically, used in quantifying an attribute with respect to a specified scale Measurement Unit: a particular quantity, defined and adopted by convention, with which other quantities of the same kind are compared in order to express their magnitude relative to that quantity Measurement Scale: (informally) a mathematical structure assuring that predicates about entities in the real world are equivalent to predicates in the numerical systems For more information: http://www2.umassd.edu/SWPI/curriculummodule/em9ps/em9.part3.pdf EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

Technical Document Structure We plan to write a reference document to be published in EDMS and representing the official definitions of measures Starting from WMS and VOMS, one evolving document for all IT/CZ services? STRUCTURE: Introduction Background on Measurement Theory Measures Definition by Systems WMS VOMS … TITLE: Definition of Measures for the … WMS and VOMS gLite IT/CZ cluster services EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

Template for Measure Definition ID: e.g., an identifier at least unique within the document System: e.g., WMS Component: e.g., Job Controller Attribute: e.g., Waiting Requests Measurement Unit: e.g., request Measurement Scale: i.e., nominal, ordinal, interval, ratio, absolute Description: Measurement Method e.g., grep " g$“ $GLITE_WMS_TMP/workload_manager/input.fl|wc -l EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

The Measurement Process Once a measure has been defined, the developers responsible for the affected piece of software must provide an efficient recipe to extract the information by using e.g., a shell command The ideal would be to have: short term: the recipe to gather each attribute measure by using a shell script (e.g., grep of a log file) medium term: a shell command returning the last measure for all the define attributes in (at least) two format: xml + raw long term: a web service port getStats? EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

A Measurement Construct EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005

Measures for WMS and VOMS Review http://www.cnaf.infn.it/~andreozzi/wiki/Work/WMS http://www.cnaf.infn.it/~andreozzi/wiki/Work/VOMS EGEE JRA1 IT/CZ Meeting - Bologna, 10 November 2005