Logging and Log Files

dsTest writes to log files that reside in the directory from which dsTest was launched. The logs are primarily a troubleshooting tool and under normal conditions can be ignored. Logs are invaluable, however, when it becomes necessary to enlist the help of our support personnel in diagnosing and resolving problems.

You can specify the log level, the maximum number of files to retain, and the maximum size of each file when you launch dsTest. You can also modify those settings as well as forcibly close a log file or add a message to the current file while dsTest is running with the log command.

The name of the file currently in use is always ds_log. When it reaches the maximum size allowed it is renamed as ds_log_0 and a fresh log named ds_log is started. As each log file fills, the file names of the older log files are incremented until the maximum number of files is reached and then the oldest log file is discarded.

Log Level

You can control the amount of information that is logged during application initialization and during application operations by using the -L and -l launch options respectively along with the level of logging desired. The default log level is 4.

Level 0 - Restricts logging to fatal errors.

Levels 1-10 - Enables logging at the specified level. As the level number increases, more messages are logged and the messages are more verbose but the criticality of the messages decreases.  Conversely, the smaller the level number is the more critical the messages are. Level 1 messages, for example, log errors while level 4 messages are informative.  The level of information increases through level 10, which includes extensive processing information and records the content of every packet sent and received.  Since increased logging consumes additional resources, application performance can be impacted when operating at a level higher than 6 and those levels are typically only used when troubleshooting.

Level 11 - Enables logging at level 10 and forces every message to be logged. When the application is running under a heavy load, application operations take precedence over lower priority operations such as logging and some log messages may be discarded (although you can control which messages may be discarded with the -q launch option).  This level mandates that every log message is recorded, at the expense of application performance if necessary, and as such should only be used in extreme circumstances.

Operating dsTest with a high log level will impact the performance of the system and should only be done temporarily while debugging or when instructed by Support. When you are finished collecting the log information, the log level should be returned to 6 or less.