Loadrunner Logging Options

There are a number of different functions provided by Loadrunner for logging, including:

• lr_message
• lr_output_message
• lr_error_message
• lr_log_message
• lr_debug_message
• lr_vuser_status_message

This post provides a script illustrating each of these logging methods, and a description of the differences.

lr_message
The limitation of lr_message is that no source file (such as Action.c) or line number is provided.

lr_output_message

lr_output_message includes source file and line number information which is useful for debugging issues.

lr_error_message

lr_error_message flags the message as an error rather than informational.

lr_log_message

lr_log_message can reduce some network traffic during load tests by not sending messages to the load test output window.

lr_debug_message

lr_debug_message can write message conditionally on certain logging settings being enabled

lr_vuser_status_message

lr_vuser_status_message updates the vuser status field during load tests

The following script illustrates the various logging methods.

Script

Action()
{
// setup test message data
int msgLevel;
char *message = "This is a test message.";
        // save string to a parameter
        lr_save_string(message, "messageParam");

// lr_message test
lr_message("---------------------- lr_message --------------------------");
lr_message("--- lr_message does not show the source file and line number");
lr_message("--- lr_message: %s", message);
lr_message("----------------- end lr_message ---------------------");

// lr_output_message test
lr_message("------------------- lr_output_message -----------------------");
lr_message("--- lr_output_message does show the source file and line number");
lr_output_message("--- lr_output_message: %s", message);
lr_message("----------------- end lr_output_message ---------------------");

        // lr_error_message test
lr_message("------------------- lr_error_message -----------------------");
lr_message("--- lr_error_message writes a message with an Error log level");
lr_error_message("--- lr_error_message: %s", message);
lr_message("----------------- end lr_error_message ---------------------");

// lr_log_message test
lr_message("------------------- lr_log_message ------------------------");
lr_message("--- lr_log_message does not send messages to the output window and could therefore reduce network traffic between agent and load generator in some situations");
lr_log_message("--- lr_log_message: %s", message);
lr_message("----------------- end lr_log_message ---------------------");

// lr_debug_message test
lr_message("------------------- lr_debug_message -----------------------");
lr_message("--- lr_debug_message writes a message if the specified log settings are set");
    msgLevel=lr_get_debug_message();
if (msgLevel & LR_MSG_CLASS_BRIEF_LOG  ) {
lr_message("standard log is enabled");
} else if (msgLevel & LR_MSG_CLASS_EXTENDED_LOG  ) {
lr_message("extended log is enabled");
} else if (msgLevel & LR_MSG_CLASS_DISABLE_LOG  ) {
lr_message("log is disabled");
} 

// log message if brief or extended log are enabled
lr_debug_message(LR_MSG_CLASS_BRIEF_LOG | LR_MSG_CLASS_EXTENDED_LOG, "--- lr_debug_message: %s", "This is written if brief or extended log is enabled");

// disable  brief and extended log
        lr_set_debug_message(LR_MSG_CLASS_BRIEF_LOG, LR_SWITCH_OFF); 
        lr_set_debug_message(LR_MSG_CLASS_EXTENDED_LOG, LR_SWITCH_OFF);

// now the debug message should not be written
lr_debug_message(LR_MSG_CLASS_BRIEF_LOG | LR_MSG_CLASS_EXTENDED_LOG, "This should not be written to log because brief and extended log are both disabled");

// re-enable extended log
        lr_set_debug_message(LR_MSG_CLASS_EXTENDED_LOG, LR_SWITCH_ON);

lr_message("----------------- end lr_debug_message ---------------------");

// lr_vuser_status_message
// lr_log_message test
lr_message("------------------- lr_vuser_status_message ------------------------");
lr_message("--- lr_vuser_status_message updates the status field of the vuser status area.  It does not write to the log");
lr_vuser_status_message("--- lr_vuser_status_message: %s", message);
lr_message("----------------- end lr_vuser_status_message ---------------------");

return 0;
}

Output

Running Vuser...

Starting iteration 1.

Starting action Action.

---------------------- lr_message --------------------------

--- lr_message does not show the source file and line number

--- lr_message: This is a test message.

----------------- end lr_message ---------------------

------------------- lr_output_message -----------------------

--- lr_output_message does show the source file and line number

Action.c(19): --- lr_output_message: This is a test message.

----------------- end lr_output_message ---------------------

------------------- lr_error_message -----------------------

--- lr_error_message writes a message with an Error log level

Action.c(25): Error: --- lr_error_message: This is a test message.

----------------- end lr_error_message ---------------------

------------------- lr_log_message ------------------------

--- lr_log_message does not send messages to the output window and could therefore reduce network traffic between agent and load generator in some situations

--- lr_log_message: This is a test message.

----------------- end lr_log_message ---------------------

------------------- lr_debug_message -----------------------

--- lr_debug_message writes a message if the specified log settings are set

extended log is enabled

--- lr_debug_message: This is written if brief or extended log is enabled

----------------- end lr_debug_message ---------------------

------------------- lr_vuser_status_message ------------------------

--- lr_vuser_status_message updates the status field of the vuser status area.  It does not write to the log

----------------- end lr_vuser_status_message ---------------------

Ending action Action.

Ending iteration 1.

Ending Vuser...

Starting action vuser_end.

Ending action vuser_end.

Vuser Terminated.

How To Show Response Times in LoadRunner Vugen with Logging Disabled

Occasionally you want to see transaction response times in Loadrunner Vugen when logging is disabled, perhaps because log output is too verbose to easily see response times.  In that case, one convenient technique is to output response times using the lr_get_transaction_duration() function:

Script Example
Action()
{
  char *transactionName = "test_transaction";
  lr_start_transaction(transactionName);
  SimulateTransactionLogic();
  lr_output_message("ResponseTime,%f", lr_get_transaction_duration(transactionName));
  lr_end_transaction(transactionName, LR_AUTO);
}

SimulateTransactionLogic()
{
  lr_think_time(0.1);
}

Console Output With Logging Disabled

Action.c(9): ResponseTime,0.103419

Vuser Terminated.

Console Output With Logging Enabled

Running Vuser...

Starting iteration 1.

Starting action Action.

Action.c(5): Notify: Transaction "test_transaction" started.

Action.c(17): lr_think_time: 0.10 seconds.

Action.c(9): ResponseTime,0.106920

Action.c(10): Notify: Transaction "test_transaction" ended with "Pass" status (Duration: 0.1083 Think Time: 0.1005).

Ending action Action.

Ending iteration 1.

Ending Vuser...

Starting action vuser_end.

Ending action vuser_end.

Vuser Terminated.