Using Excel data source with a Load test - works for 1 user but not for 10 users  
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Serend





PostPosted: Visual Studio Team System - Testing, Using Excel data source with a Load test - works for 1 user but not for 10 users Top

Hello,

I have a webtest that uses an Excel sheet data source. (The same row is used 4-5 times in the course of the test. There are 2 columns in the sheet.) When I run this in a load test with 1 user, it works fine. When I run it with 10 users at constant load, only about 25% of the tests are completed successfully.

Could this be because the users are simultaneously trying to access the same Excel file and running into conflicts Or it might go like this: user 1 accesses row 1, then user 2 goes to row 2, and when user 1 comes back he hits row 3 instead of row 1 again.

Another one of my webtests worked great with 10 concurrent users. This test only accesses the data source once per test, which is why I'm thinking there might be some issue with the data source being accessed multiple times...

Any insights are appreciated. Thanks!



Visual Studio Team System36  
 
 
slumley MSFT





PostPosted: Visual Studio Team System - Testing, Using Excel data source with a Load test - works for 1 user but not for 10 users Top

The problem is not that multiple users are trying to access the same excel file. The engine loads all the data once at the beginning of the test and then iterates through the datasource. Is your datasource marked sequential. You can check by clicking on the table under the datasource node in the editor. If it is, then each iteration of the webtest will grab the next row in the datasource. There is no guarantee that a particular user will get a certain row. Your example has it correct. If the order of tests was

User1 - Row 1
User2 - Row 2
User1 - Row 3
User3 - Row 4

Does this answer your question




 
 
Serend





PostPosted: Visual Studio Team System - Testing, Using Excel data source with a Load test - works for 1 user but not for 10 users Top

Thanks for your reply, that helps clarify what's going on. We are going to look into the code for that page, the problem is most likely there and not in the data source.