The Core Technologies Blog

Our Software // Windows Services // 24×7 Operation


How to use the Event Viewer to troubleshoot problems with a Windows Service

A windows service, designed to run “headless” and unattended in the background, cannot easily employ conventional popup windows to report its activities as a user may not even be logged on. Instead, a service is encouraged to send important communication to the Windows Event Log – an administrative utility that collects and stores messages and events. Once recorded, these messages can be very helpful in troubleshooting problems, for example when a service stops unexpectedly or when it fails to start at all.

Viewing Events from Windows Services

Use Microsoft’s Event Viewer to see messages written to the Event Log. Start the application by clicking on the Start button and typing in Event Viewer, or from the Control Panel (search for it by name). The somewhat cluttered window should come up after a few seconds:


Event Viewer

The left hand side shows a tree grouping the various logs captured on your machine. The events from Windows Services (and other applications running on your PC) are filed under Windows Logs > Application. Navigate to that section to load the events in the center of the window, with the entire list in the top and details of the highlighted event underneath:


Event Viewer - Application Log

Messages from your windows service will have the display name of the service in the Source column.

Important Components of an Event

The Event Viewer shows over 10 pieces of information associated with each event, including:

  • Level – How important is this event?

    Each event is classified into one of three categories:

    Information: An informative yet unimportant event. You will probably see a lot of these, and they can be safely ignored unless you are digging into a specific issue from an application or service.

    Warning: A moderately important event. These don’t necessarily signify a failure, and your software will probably limp along, but they should be reviewed regularly to see if anything mentioned can be resolved.

    Error: Indicates a critical problem or failure that may deserve your immediate attention!

  • Date and Time – When did this event occur?

  • Source – Which application reported this event?

    As mentioned before, an event written by a Windows Service will contain the service’s display name as the Source.

  • Description – Which happened?

    The full description shown prominently in the lower pane will (hopefully) provide the relevant details of the event.

For example, this information event is from the Interactive Services detection service (“UI0Detect”) reporting that Notepad is showing itself in Session 0:


Interactive Services Detection Service Event

Viewing Events about Windows Services

While the Application log keeps track of events from a running service, the Windows Logs > System area records when services are started, stopped, crash or fail to start. Look for events with the Source set to Service Control Manager (SCM). For example, here is the SCM telling us that the Windows Print Spooler service has crashed:


Event Viewer System Event

Viewing Events from AlwaysUp and Service Protector

Both AlwaysUp and Service Protector write messages to the Application section of the event logs (Windows Logs > Application).

For AlwaysUp, events from your application named “My Application” will be logged with Source set to My Application (managed by AlwaysUpService). The Event Log Messages Page lists and explains the events reported.

For Service Protector, events related to your service named “MyService” will have a Source of ServiceProtector: MyService.

And for both applications, events related to the starting and stopping of the underlying services themselves appear in the Windows Logs > System section. Look there if you have a problem with AlwaysUp itself failing to start at boot.

Posted in Windows Services | Tagged , , , | Leave a comment

Leave a Reply

Your email address will not be published. Required fields are marked *

*

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>