Bender makes it easy to build load testing applications for services using protocols like HTTP, Thrift, Protocol Buffers and many more. Bender provides a library of flexible, powerful primitives that can be combined (with plain Go code) to build load testers customized to any use case and that evolve with your service over time. Bender provides two different approaches to load testing. The first, LoadTestThroughput, gives the tester control over the throughput (QPS), but not over the concurrency. This one is very well suited for services that are open to the Internet, like web services, and even backend Thrift or Protocol Buffer services, since it will just keep sending requests, even if the service is struggling. The second approach, LoadTestConcurrency, gives the tester control over the concurrency, but not over the throughput. This approach is better suited to testing services that require lots of concurrent connections, and need to be tested for resource limits.