Changes between Version 4 and Version 5 of GEMINI/Tutorial/GEC19/GENI_Desktop_and_GEMINI_blipp/ExecuteExperiment
- Timestamp:
- 03/11/14 22:53:45 (10 years ago)
Legend:
- Unmodified
- Added
- Removed
- Modified
-
GEMINI/Tutorial/GEC19/GENI_Desktop_and_GEMINI_blipp/ExecuteExperiment
v4 v5 109 109 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. 110 110 111 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 use the wrapper(assumes default csh on default Fedora 15 images).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). 112 112 113 113 {{{ 114 setenv NL_WRAPPER/usr/local/lib/nl_wrapper.so114 setenv LD_PRELOAD /usr/local/lib/nl_wrapper.so 115 115 setenv NL_FILE /tmp/iperf.log 116 116 … … 135 135 ... 136 136 }}} 137 138 Once a BLiPP test has been configured for the given node, the event type drop down will contain entries for each of the statistics recorded by the !NetLogger wrapper. In the iperf case, the client performs a number of write() calls to send data to the server. 139 140 [[Image(wiki:GEMINI/Tutorial/Images:nl_wrapper.et.png)]] 141 142 Here is a summary of each statistic: 143 144 * - count 145 * - sum 146 * - mean 147 * - min 148 * - max 149 * - standard deviation. 150 * 151 * These statistics are tracked for: 152 * - 'v': the value 153 * - 'g': the ratio of the duration(ns)/value (prefix=g for gap) 154 * - 'r': the ratio of the value/duration(ns) (prefix=r for rate) 155 156