Performance Tesing的定义：
Performance testing is a type of testing intended to determine the responsiveness, throughput, reliability, and/or scalability of a system under a given workload. Performance testing is commonly conducted to accomplish the following:
. Assess production readiness.
. Evaluate against performance criteria.
. Compare performance characteristics of multiple systems or system configurations.
. Find the source of performance problems.
. Support systen tuning.
. Find throughput levels.
Performance Testing的分类：
Performance testing: This type of testing determines or validates the speed, scalability, and/or stability characteristics of the system or application under test. Performance is concerned with achieving response times, throughout, and resource utilization levels that meet the performance objectives for the project or product.
Load Testing: This subcategory of performance testing is focus on determing or validating performance characteristics of the system or application under test when subjected to workloads and load volumes anticipated during production operations
StressTesting: This subcategory of performance testing is focus on determing or validating performance characteristics of the system or application under test when subjected to conditions beyond those anticipated during production operations