Event Logging - Log Types

Event Logs - Log Types

Event log and event source creation are privileged operations. Creation of a new event log, new event source, or reassignment of an existing event source to a different event log is an administrative operation and must be done under an Admin user's credentials. To enable application event logging (for Studio or Runtime), you must change the corresponding configuration files. Then, return to the application and use the Diagnostics Configuration options. For more information, see Application Event Messages.

If a deployed Studio project uses either Entry/Exit Point logging or the EventLog Component, Studio tries to create and write to the designated logs:

The EventLog component writes to the following by default:

LogName: OS_AUTOMATION, Source: OpenSpan Automation

Runtime or Studio write to the following by default:

LogName: OS_EVTLOG, Source: Runtime

See the Limitations section for requirements on writing to the Windows event logs.

Application event messages

To log application event messages originating from running Studio projects, add the following XML code to the Diagnostics section of the configuration file:

<publisher mode="on" trace_mode="on"

exception_mode="on"

assembly="OpenSpan"

type="OpenSpan.Diagnostics.Publishers.EventLogPublisher" />

After modifying the Studio or Runtime configuration file, use the Diagnostics Configuration dialog in Studio or Runtime or both and do the following:

Set the Application Diagnostics Settings mode to On.
Set EventPublisher mode to On.
Use the Diagnostics Configuration - Log Categories to set the event categories and corresponding levels for which messages are written to the log.
Configure the event log by using the Event Log Configuration dialog (in Studio, Options > OpenSpan > Event Log Configuration dialog).For more information, see Event Log Configuration.

Automation entry/exit point messages

To log automation Entry point and Exit point event messages (such as: Entry point 'Execute' execution started, Entry point 'Execute' execution completed), set the LogEvents property to True on the Entry and/or Exit point and use the Event Log Configuration dialog (Tools > Options > OpenSpan) to Enable logging.

Entry/Exit point events are logged to the Runtime application log as set up in the Event Log Configuration dialog and configuration file. Note that event logging at the application level must be configured and enabled (as described in the Application Event Messages section of this topic).

For more information, see Event Logging - Entry Point Logging.

Limitations

There are several limitations regarding the use of event logging:

Windows only allows an event source to be registered with a single event log at a given time. If a resource attempts to register a source with an event log and that source is already registered on a different event log, this results in an error. Typically, the source string is used to identify the origin of a given event message and this source is usually registered during application installation. Studio does not reassign the event source from one event log to another when the condition arises where a user specifies an event source for an event log item which is already in use, as this could potentially break third-party applications.
Most event log management operations are privileged. This includes the...
- Creation of a new event log
- Deletion of an existing event log
- Modification of event log properties (maximum size, overflow policy)
- Registration of an event source
If an event log operation cannot be performed within Runtime due to security limitations, the exception generated is displayed using the normal exception display dialog as well as logged to the diagnostic log. The event log is rendered disabled, so all interactions with the event log within the system will be no-ops, thus not interfering with other operations. Generally this kind of exception occurs when a Runtime project attempts to create an event log and/or source on a computer and lacks permissions to do so.
To use the event logging feature with other event logs, instead of the default event logs and sources which are created during the Studio/Runtime installation, it is recommended that the installation process also create the desired event logs and sources which will be used for logging events by Runtime.
When using non-local event logs (where the MachineName is not ".”), it is possible for network outages to result in failures of event log operations. In particular, referencing an event log on a host which is not available will result in a network I/O exception. This, however, requires Windows to wait for its network timeout interval (90 seconds by default) before the exception is generated. The use of non-local event logging operations is not recommended because of this potential issue.

Related information

Event Log Configuration

Entry Point Logging

Internal Events Logged

EventLog Component

Using the EventLog Component