Overview - Brief Description of Feature

This feature allows for terminal and controller applications to much more aggressively log trace and diagnostics information to the controller with minimal controller disk impact. This feature is designed to allow applications to write higher volumes of non-critical log data with minimal controller disk impact.  An additional benefit of this feature is that real-time terminal log data will be saved even in cases when the terminal is powered off and restarted.

Problem - What Problem Does the Feature Solve?

4690 terminal and controller applications have always been limited in the amount of debug logging they can do due to various architectural aspects of the 4690 operating system.  In particular, since 4690 stores financial transaction data, the disk subsystem is designed to ensure that all data written to the disk immediately makes it to the physical disk.  This is critical for most file writes but it also makes file writing the typical limiting performance factor on a 4690 system and has kept applications from being able to log even reasonable amounts of progress or debug logging information. 

A second problem that occurs on 4690  relates to unexplained terminal restarts.  When terminals are restarted by store personnel, there is little information available to understand what was going on in the terminal prior to the restart.  This feature will allow for additional log file data to be captured.

Solution - Short Description of How the Feature Works

This feature of InSight is installed on the controller and monitors for file creates and opens for file names as specified in a configuration file, for example, "C:\TERMLOG\TSALES???.LOG."  Writes to configured log files are buffered in memory until the buffer becomes full or until a time period expires or until the file is manually flushed.  A status utility is provided that allows for manual flushing and displays file caching status and statistics.  Typical volume-condition write savings are 98 percent or higher.

On Request - Ideas Being Considered as Future Enhancements

The following enhancements are being considered:

• Circular Wrap Buffer/Flush on Close - with this option, debug/trace information is kept in a wrapping cache memory buffer on the controller.  On file close (such as when a terminal restarts), the circular buffer is written to disk.  This option logs minimal amounts of information to disk but will log needed information just prior to a poroblem or failure is available.
• Redirect to NAS - This option will provide a mechanism for forwarding log data to a disk on the local LAN instead of to the controller disk.  NAS access can be designed to offer writes that are faster than local writes.