Bringing It All Together with SQL Nexus - SQL Server 2012 Internals and Troubleshooting - page 345

NOTE You need SQL Server Native Client 10.0 installed on your machine to use
OSTRESS. This can be downloaded from the latest SQL Server 2008 Feature
Pack available on the Microsoft Downloads site.

The following code snippet applies i lters for Sesison IDs 51, 52, and 53, and excludes events
generated by an application named SQLDIAG or hostname MyLaptop. The output folder will con-
tain the . RML i les for SPID 51, 52, and 53, which can be used by OSTRESS for generating load.

readtrace -S. -E -ddbRMLUtilDemo
-I"D:\RML\RMLUtil_demo.trc" -A"!SQLCMD" -s51 -s52 -s53 -o"D:\RML\output"
-H"!MyLaptop" -A"!SQLDIAG

In addition to stress testing, you may want to interject random events. An example of such an event
would be to introduce a timeout after a specii ed amount of time. OSTRESS is designed especially
for this type of stress scenario. It is also useful for reproducing and stressing query cancellations
(attention signals) whereby either a query time-out or cancellation has been issued by the client, as
well as many other actions. The RML Utilities Help i le has detailed documentation about the utility.

Things to Remember About OSTRESS
➤

OSTRESS parameters are case sensitive.

➤

Parameters must be separated with the hyphen (-) or forward slash (/)
character.

➤

Parameters that contain spaces or special characters should be enclosed in
quotation marks.

➤

White space is not permitted between the parameter indicator and its value.

OSTRESS gives you the unique capability to specify the number of connections and iterations for a
particular query or queries present in an RML i le. The following example executes
SELECT @@VERSION against the default instance using 50 threads with 100 iterations each:

Ostress.exe -Q"Select @@VERSION" -oc:\temp\output -n50 -r100

NOTE Using ostress.exe -? from the RML Utilities command prompt will
return a list of the parameters available for the OSTRESS executable. You might
also want to add the location of the SQL Nexus and RML Utilities directories
to your %PATH% environment variable so that you can use these utilities from
any command prompt window, obviating the need to fully qualify their path or
browse to the directory containing these EXEs.