QueryTraceA function

12/05/2018
2 minutes to read

The QueryTrace function retrieves the property settings and session statistics for the specified event tracing session.

The ControlTrace function supersedes this function.

Syntax

ULONG WMIAPI QueryTraceA(
  TRACEHANDLE             TraceHandle,
  LPCSTR                  InstanceName,
  PEVENT_TRACE_PROPERTIES Properties
);

Parameters

TraceHandle

Handle to the event tracing session for whose properties and statistics you want to query, or NULL. You must specify SessionHandle if SessionName is NULL. However, ETW ignores the handle if SessionName is not NULL. The handle is returned by the StartTrace function.

InstanceName

Pointer to a null-terminated string that specifies the name of the event tracing session whose properties and statistics you want to query, or NULL. You must specify SessionName if SessionHandle is NULL.

To specify the NT Kernel Logger session, set SessionName to KERNEL_LOGGER_NAME.

Properties

Pointer to an initialized EVENT_TRACE_PROPERTIES structure.

You only need to set the Wnode.BufferSize member of the EVENT_TRACE_PROPERTIES structure. You can use the maximum session name (1024 characters) and maximum log file name (1024 characters) lengths to calculate the buffer size and offsets if not known.

On output, the structure members contain the property settings and session statistics for the event tracing session.

Starting with Windows 10, version 1703: For better performance in cross process scenarios, you can now pass filtering in to QueryTrace for system wide private loggers. You will need to pass in the new EVENT_TRACE_PROPERTIES_V2 structure to include filtering information. See Configuring and Starting a Private Logger Session for more details.

Return value

If the function succeeds, the return value is ERROR_SUCCESS.

If the function fails, the return value is one of the system error codes. The following table includes some common errors and their causes.

Return code	Description
ERROR_BAD_LENGTH	One of the following is true: The Wnode.BufferSize member of Properties specifies an incorrect size. Properties does not have sufficient space allocated to hold a copy of the session name and log file name (if used).
ERROR_INVALID_PARAMETER	One of the following is true: Properties is NULL. SessionName and SessionHandle are both NULL.
ERROR_ACCESS_DENIED	Only users running with elevated administrative privileges, users in the Performance Log Users group, and services running as LocalSystem, LocalService, NetworkService can query event tracing sessions. To grant a restricted user the ability to query trace sessions, add them to the Performance Log Users group or see EventAccessControl. Windows XP and Windows 2000: Anyone can control a trace session.
ERROR_WMI_INSTANCE_NOT_FOUND	The given session is not running.

Remarks

Controllers call this function.

To update the property settings and session statistics for an event tracing session, call the UpdateTrace function.

Requirements


Minimum supported client	Windows 2000 Professional [desktop apps \| UWP apps]
Minimum supported server	Windows 2000 Server [desktop apps \| UWP apps]
Target Platform	Windows
Header	evntrace.h
Library	Advapi32.lib
DLL	Advapi32.dll