Changes between Version 5 and Version 6 of GEMINI/Tutorial/GEC19/GENI_Desktop_and_GEMINI_blipp/ExecuteExperiment


Ignore:
Timestamp:
03/11/14 22:57:25 (10 years ago)
Author:
ezkissel@indiana.edu
Comment:

--

Legend:

Unmodified
Added
Removed
Modified
  • GEMINI/Tutorial/GEC19/GENI_Desktop_and_GEMINI_blipp/ExecuteExperiment

    v5 v6  
    107107== __Exercise Task 2 -- Instrument existing application __ ==
    108108
    109 In this exercise, we will make use of a transparent !NetLogger wrapper than can intercept standard socket calls in existing applications.  This includes read()/write() and send()/recv().  When using the wrapper, you can specify an output file where the log messages are stored.  The !NetLogger probe instructions above can be used to let BLiPP push those measurements into the measurement store for graphing and archiving as we did before.
     109In this exercise, we will make use of a transparent !NetLogger wrapper than can intercept standard socket calls in existing applications.  This includes read()/write() and send()/recv().  When using the wrapper, you can specify an output file where the log messages are stored as well as the summary interval.  The wrapper uses a version of !NetLogger called !NL-Calipers, which calculates and stores in-memory summary statistics over each event encountered.  The NL_INTERVAL variable determines how frequently those summary statistics are reported and the counters reset.
    110110
    111 We will use 'iperf' as our test application to instrument with the wrapper library.  The iperf program should already be installed on the GEMINI intrumentized node.  If not, you can 'yum install iperf' or select another application to test with.  The following is an example of how to enable the wrapper using the Linux LD_PRELOAD mechanism (assumes default csh on default Fedora 15 images).
     111The !NetLogger probe instructions above can be used to let BLiPP push the collected !NL-Calipers measurements into the measurement store (MS) for graphing and archiving as we did in the previous exercise.  We will use 'iperf' as our test application to instrument with the wrapper library.  The iperf program should already be installed on the GEMINI intrumentized node.  If not, you can 'yum install iperf' or select another application to test with.  The following is an example of how to enable the wrapper using the Linux LD_PRELOAD mechanism (assumes default csh on default Fedora 15 images).
    112112
    113113{{{
    114114setenv LD_PRELOAD /usr/local/lib/nl_wrapper.so
     115setenv NL_INTERVAL 1     # default is 1 second summaries
    115116setenv NL_FILE /tmp/iperf.log
    116117
     
    141142
    142143Here is a summary of each statistic:
    143                                                                                                                    
    144  * - count                                                                                                                                       
     144                                                                                                                                                                                                                                                       
    145145 * - sum                                                                                                                                         
    146146 * - mean                                                                                                                                       
     
    150150 *                                                                                                                                               
    151151 * These statistics are tracked for:                                                                                                             
    152  *   - 'v': the value                                                                                                                 
     152 *   - 'v': the recorded value                                                                                                                 
    153153 *   - 'g': the ratio of the duration(ns)/value (prefix=g for gap)                                                                                   
    154154 *   - 'r': the ratio of the value/duration(ns) (prefix=r for rate)