Session Topic:Accelerate Enterprise Application Performance with speed, consistency and scalability

Transcription

1 Session Topic:Accelerate Enterprise Application Performance with speed, consistency and scalability Conference Name: 13th Annual International Software Testing Conference (STC 2013) Author Name: Mohan Kumar B S Mail Id: mohan.kumar.b.s@sap.com Company: SAP Labs India Private Ltd, #138, EPIP, Whitefield, Bangalore

2 Abstract Enterprise Applications are designed to run complex applications for bigger Business Enterprises. Most of the current enterprises exist globally. It makes mandate for any Enterprise Business Applications to deliver performance with speed, consistency and scalability. Most of the bigger enterprises eventually can grow bigger either by organic growth or merger/acquisitions. It is extremely important for Enterprise applications to scale in the similar passion without much change in the hardware requirements. Performance is one of the most important aspects concerned with the quality of software. It indicates how well a software system or component meets its requirements with respect to speed, stability and scalability. Although the functionality supported by a software system is apparently important, it is usually not the only concern. Study says that 1 out of 4 customer complaints are targeted at Performance issues. Non-compliance to performance can cause Increased Total Cost of Ownership (TCO) and increased energy consumption for the companies Unreliable and Irreproducible system behaviors Unpredictable and Unacceptable response times Severe impact on Company s business Most of the Enterprise Applications are follows 3-tier or multi-tier software architecture, which has presentation (front end) layer, application layer and persistence (database layer). This session covers following aspects of performance and scalability of Enterprise Applications. Typical Architecture of Enterprise Applications Strategy to achieve better performance and scalability Different Key Performance Indicators to assess in each layers Testing process to find performance and scalability bottlenecks Case study on how SAP adopts performance engineering best practices to achieve performance and scalability.

3 Enterprise Applications are designed to run complex applications for bigger Business Enterprises. Most of the current enterprises exist globally. It makes mandate for any Enterprise Business Applications to deliver performance with speed, consistency and scalability. Some of the business needs in the enterprise world to achieve good performance and scalability- Most of the bigger enterprises eventually grow bigger either by organic growth or merger/acquisitions Enterprise applications means higher volume of data processing and higher user concurrent access Possible Hardware and Network Bandwidth constraints Some practices of single global instance setup Bigger hardware means higher cost It is extremely important for enterprise applications to scale in the similar passion without much change in the hardware requirements. Performance is one of the most important aspects concerned with the quality of software. It indicates how well a software system or component meets its requirements with respect to speed, stability and scalability. Although the functionality supported by a software system is apparently important, it is usually not the only concern. Study says that 1 out of 4 customer complaints are targeted at Performance issues. What is performance &scalability? Performance refers to the total effectiveness of a computer system, including throughput, individual response time, and availability. Programming for good performance thus means making conservative use of critical resources, keeping response time at a minimum, taking into consideration aspects of network communication, as well as ensuring the scalability of the software. Scalability, in most general terms, means the degree to which a scenario, component or system can be expanded (and reduced) in size, volume, or number of users served and continue to function properly and predictably. Characteristics of Application Performance: Speed - Does the application respond quickly enough for the intended users? Scalability Will the application handle the expected user load and beyond? Stability Is the application stable under expected and unexpected user loads?

4 Enterprise Software Architecture: Possible Performance Metrics: Response time user experience / productivity System throughput business requirement, system resource consumption, IT budget Memory consumption Good performance: If the performance metrics match the business requirements or Service Level Agreements ( expectation handling ) Several parts that constitute the end-to-end (E2E) response time: Server response time Network time Frontend time

5 Dimensions and Effects of Scalability Some of the important key performance indicators

6 Identifying the performance critical scenarios The performance test scenarios are: Representative Reproducible Right to the point Representative in the sizing environment includes Bread-and-butter transactions because they cause the greatest load, such as sales order entry Critical business cases that must run in a tight time frame, such as settlement runs at the end of a period, nightly MRP runs Reproducible test cases Conducting the test several times must not change the load behavior Can be rapidly understood and followed through Remain the same over the years/releases Right to the point Pragmatic, we don't want to squeeze out the last 10% Ensuring Scalability with Performance Tests Approaches

7 Performance Testing Steps : 1. Identify the performance critical scenarios 2. Determine the expected throughput figures and/or user and system response times For example: Upload of 500,000 sales order line items in two hours 23 million s in eight hours Processing of 100,000 workflow items per hour Processing of nn HTTP requests per sec from mm parallel users Usually these figures are part of a requirement or specification document 3. Determine the complete set of functionalities needed for the performance test and the resulting software components 4. Establish test scenarios for the processes Specify in detail and document well Process steps Input/output for the steps Customizing environment 5. Determine the data distribution i.e., the type of master data you need Avoid artificial bottlenecks; for example, all orders use the same customer and products It is not enough to create a vast amount of data by simply copying it 6. Perform the initial capacity planning for the performance test system Based on measurements in the test or development system of the same or very similar test scenario 7. Define procedure for repeatable test executions Starting conditions must allow reproducible measurements It might be necessary to ensure this, using a backup and restore strategy; in other cases, a clean-up program may be sufficient Even if you test in a small system, you ought to have regular back-ups in order to start a test from scratch again or to repeat a test phase 8. Create test system and system infrastructure Ensure that the system landscape is well-configured Prepare test environment In some cases it makes sense to start testing with a small system that you gradually extend

8 9. Determine the methods and tools for performance testing and analysis Decide which tools are used for testing Decide which tools are used for analysis(tracing) Decide which tool to simulate load test(if load testing planned) Some tools require expert knowledge 10. Create the actual test data environment For example: Create the business partners which are used in sales order processing 11. Run the single-user test Measure and analyze the performance Eliminate performance bugs Check scalability of application Linear behavior Critical path lengths and locking Proper indexes 12. Run the multi-user load test Start with a small load and increase load step-by-step towards the final throughput target Measure the throughput Measure the resource consumption using appropriate monitoring tools Optimize system parameter settings and repeat the test executions if necessary 13. Evaluate the test results Document the achieved throughput numbers and the corresponding resource consumption Document the test system environment (hardware and software releases) carefully

9 The numbers may be needed for sizing of further systems Ensure Scalability: Improve Performance Possible Measures Add hardware Additional application servers(consider impact on DB server) Additional CPUs/memory on server(s) Tune the system Profile parameters Increase buffer sizes Re-schedule load Distribute load more evenly across servers and time Tune the application Customizing, configuration Function and performance Optimize the coding Requires time, knowledge,

10 Performance Parameters Best Practices at SAP to ensure Performance & Scalability Single User with Low Volume Speed - Does the application respond quickly enough for the intended users? Findi ngs Focu s Area s Single User with High volume Scalability with data volume - How is resource consumption per unit Concurrent Users with Low Volume Scalability with concurrent Users - How your application is scalable with additional users 1. To identify code issues Test Standard Scenario Implement Custom Code Test Customized Scenario Measure & Analyze Layer Frontend Layer Application Layer Database Layer Browser CPU Time Response Time & CPU Time Appropriate Index and Complete Where clause Round Trips Data volume transferred Buffers and Caches Data volume transferred Peak Memory & Memory Leak Identical Selects

11 2. To identify Linearity Issues Test with Low Volume Increase Volume Linearly Conduct Test Measure & Analyze Linearity Resource consumption should be linear with increase in volume of data Volume of Data 3. To identify Concurrency Issues Single User Test Ramp-Up Users Linearly Conduct the Test Measure & Analyze Linearity Resource consumption should be linear with increase in concurrent users Stability : Response time should be constant until resource consumption threshold is reached