What is Load Testing? 10 basic steps to create load testing. Questions Summery Copyright SELA SELA software && Education Labs Ltd. 14 18 Baruch Hirsch St.Bnei Brak Brak 51202 51202 Israel Israel 2
Load testing is the process of putting demand on a system or device and measuring its response under normal load Amazon's 2 hour crash thwarts shoppers $29,000 per minute Total estimated lose $14.835 billion Everyone thought "They know how to handle load". How should my application behave under load? Response time -Example: the product catalog must be displayed in less than 3 seconds. Throughput Example: the system must support 100 requests per second. Resource utilization- CPU, memory, disk I/O, and network I/O. Maximum User Load- Determine how many users can run on your testing hardware configuration.
What are scenarios? Scenarios are anticipated user paths that generally incorporate multiple application activities. How do you identify scenarios? Key scenarios are those for which you have specific performance goals or those that have a significant performance impact. These scenarios represent business activity of users over time. Example: User performing Buy action, Registration Identify the distribution ib i / ratio of the work For each scenario identify the distribution. Scenario Buy Registration Search % Work Distribution 20 10 70 Calculate the users load per scenario Using work distribution calculate the maximum concurrent user per Scenario. Scenario Buy % Users 20 Users 200 Registration 10 100 Search Total 70 100 700 1000
Metrics are a derivative i of your performance objectives. They are used to measure your application s real time performance in comparison with your performance objectives. Network-specific metrics System-related metrics Platform-specific metrics Application-specific metrics Service level metrics Metric Accepted Level % Process Time No more than 75% % Physical Memory No more than 55% Network utilization Less than 65% Total # of Threads No more than 50 per process. help you to identify problems and bottlenecks within your application Load testing tools requires specific knowledge and each tool has his advantages and disadvantages. Perform research Wrong tool can have a significant impact on our testing process User Limit : More users = more money
What is a test case? A group of activities involved in a scenario/user profile. The test cases are created based on the scenarios and the profile mix identified d in the previous steps. Example: Buy Product (Include Login, Search, etc ) Each test case should include the expected results in such a way that each test case can be marked as a 'pass' or 'fail' after execution. TestCase: Search phone owner ID Description Expected Results 1 Open Application Application is up. 2 Perform login with user: Demo and User authorization success. password: 123 3 Search phone number : User details: 555 123456 Name: Demo User Last: Demo User City: Tel Aviv Create an automated test and set a specific load configuration for it. Example: 400 users for 1 hour And load test expected results for Test Case: Search phone owner: Category Avg. response time Resource utilization Processor time Available Memory Expected Results Lower than 8 sec. Lower than 75% Lower than 55%
Even the smallest hardware or configuration difference can have a big impact on our results Example: I have created a load environment with 2 computers that will run 10,000 concurrent users, the ISP provides 1Mbps. Each user will open browser and perform a search for dynamic word in www.live.com. Opening 5000 browsers on one machine? Do you think 1Mbps is enough bandwidth for 10,000000 users? Start small and then increase the load dincrementally. Wait enough time between each step. Incrementing the number of users slowly will make it easier to find the exact point/threshold where the system crashes or hangs due to load.
The system is considered stable. Make sure you are monitoring the load testing: Boomer Boomed Analyze the results and check against the metrics and make sure our objectives were achieved. We save each run Results and compare with other runs. in this way we may notice improvement or deterioration of the performance and load of your application. Share with other key business disciplines : business operations, senior management and maybe finance.
Can you say I say maybe My Rule is The results from one environment aren t necessarily equal to the results of another. 15 Copyright SELA SELA software && Education Labs Ltd. 14 18 Baruch Hirsch St.Bnei Brak Brak 51202 51202 Israel Israel 16
So why perform load testing if the results are inconclusive to production? Load Test helps you to estimate the behavior of the application under load. Copyright SELA SELA software && Education Labs Ltd. 14 18 Baruch Hirsch St.Bnei Brak Brak 51202 51202 Israel Israel 17 Shai Raiten Blog http://blogs.microsoft.co.il/blogs/shair Copyright SELA SELA software && Education Labs Ltd. 14 18 Baruch Hirsch St.Bnei Brak Brak 51202 51202 Israel Israel 18