Displaying I/O Metrics from an ETW Input File

The hIOmon WIOP and WIOPF both support the option of retrieving I/O operation event trace data from a Microsoft® "Event Tracing for Windows (ETW)" input log file.  The ETW input log files must include process, thread, and disk (including disk I/O initiation) event types.  Disk_File and file (including file I/O initiation) events types must additionally be included for monitoring file I/O operations.

The hIOmon WIOP and WIOPF process the event data retrieved from an ETW input log file in the same manner as with event data retrieved in real-time from the ETW facility.  Similarly, the generated summary metrics are shown by the hIOmon Disk I/O Ranger Display and the hIOmon I/O Trender Display in the same manner as the display of real-time summary I/O operations metrics (e.g., the same display options for both real-time and ETW input log I/O operation metrics).

The basic steps required to retrieve and display I/O operation metrics from an ETW input log file are:

• Stop the display of metrics from the current metrics source
• Select the particular ETW input log file from which the ETW event data is to be retrieved
• Specify the particular retrieval delay options (if any), then load a new hIOmon ETW I/O Monitor instance that will use the selected ETW input log file
• Configure the new hIOmon ETW I/O Monitor instance using the WIOP automated configuration script, which will load the default hIOmon Filter Selection into the hIOmon ETW I/O Monitor instance and activate the retrieval of event data from the selected ETW input log file
• Select the particular monitored item(s) of interest whose summary I/O metrics are to be displayed
• Unload this hIOmon ETW I//O Monitor instance after you are done displaying the contents of the associated ETW input log file

These basic steps are illustrated by the annotated screenshots below:

After first performing the steps above, click on the "Browse..." button (shown within the screenshot below).  Then select the particular ETW input log file whose ETW event data is to be retrieved.

As highlighted within the screenshot below, the "Retrieve metrics from file:" text box displays the ETW input log file from which the ETW event data is to be retrieved.  This text box is automatically updated with the full file path name of the ETW input log file chosen by means of the "Browse..." button.  Any text manually entered into this text box is ignored.

As illustrated by the screenshot above, an informative message is displayed at the bottom of the Settings window to indicate the next steps after the ETW input log file has been selected.  The screenshot below illustrates these two steps:

As indicated, any "Retrieval delay options" should be specified prior to loading the new hIOmon ETW I/O Monitor instance.  These two options enable you to effectively control the rate by which this hIOmon ETW I/O Monitor instance retrieves I/O operation event data from the ETW input log file.

The "I/O operation count delay" option can be used to specify the number of I/O operations that have to be processed/received by the hIOmon ETW I/O Monitor before waiting to retrieve the next record of ETW event data from the ETW input log file.  The default value is zero.  Note that the length of this subsequent wait period is set by the associated "Retrieval time delay" option, which must also be set to a non-zero value if this option is set to a non-zero value.  That is, a non-zero value for this option is ignored if no associated time delay period is set.

The "Retrieval time delay" option can be used to specify the number of milliseconds (if any) for which the hIOmon ETW I/O Monitor is to delay before retrieving the next record of ETW event data from the ETW input log file.  Note that a value of zero (the default) indicates that there should be no delay (i.e., wait) period.

Note again that non-zero values for these two options must be entered before clicking upon the "Load" button so as to enable these options within the new hIOmon ETW I/O Monitor instance to be created.

The new hIOmon ETW I/O Monitor must be configured after the Load step has been performed:

Clicking the "Configure" button invokes the WIOP automated configuration script, which will load the default hIOmon Filter Selection into the new hIOmon ETW I/O Monitor instance and then activate its retrieval of event data from the selected ETW input log file.

The WIOP automated configuration script will display the following prompt, which will enable you to change which devices are to be monitored by the hIOmon ETW I/O Monitor:

Note that any changes to the Filter Selection will not impact a currently-running realtime hIOmon ETW I/O Monitor.

Click on the "Metrics for monitored:" radio buttons (highlighted within the screenshot below) to populate the respective monitored-items drop-down list boxes.  Note that the ETW input log file retrieval activation by the configuration script might take some time.  Consequently, the drop-down boxes might not be immediately populated with monitored items.  Continue clicking between the radio buttons until monitored items appear within the drop-down boxes.

To display the summary metrics for a monitored item, select the monitored item from the drop-down list box and then click the "OK" button at the bottom of the Settings display window.

The hIOmon ETW I/O Monitor will continue to retrieve event data from the ETW input log file until the end of the file has been reached (at which time it will close the file).  As illustrated by the screenshot below, a message will be displayed when the ETW input file has been closed.

Click on the "Unload" button (highlighted in the screenshot above) after you are done displaying the contents of the ETW input log file.  This will result in the hIOmon ETW I/O Monitor instance being released; this unload operation will not impact the realtime hIOmon ETW I/O Monitor instance.

You can unload the hIOmon ETW I/O Monitor instance at any time that the "Unload" button appears.

You can also switch between the realtime hIOmon ETW I/O Monitor and the hIOmon ETW I/O Monitor instance that is using an ETW input log file.  Note, however, that you must stop the display refresh prior to any such metrics source change.

Also note that the realtime hIOmon ETW I/O Monitor will continue to process realtime event data from the ETW facility while you are displaying summary metrics from the hIOmon ETW I/O Monitor instance that is using the selected ETW input log file.

Similarly, the hIOmon ETW I/O Monitor using the selected ETW input log file will continue to retrieve event data from the ETW input log file while you are displaying summary metrics from the realtime hIOmon ETW I/O Monitor instance.