Design Patterns NPRG024

The Strategy pattern is used to manage different request modes. In the "one-shot" mode, a single request is sent, while the "throughput" mode sends n parallel requests. The main entry point for the algorithm is the execute method in the Executor class. Inside that method another execute method is called from common IGeneratorMode interface in order to send request(s). The execute method from Executor class gets as an argument a particular implementation of IGeneratorMode interface.

Unlike the classic version of the Strategy pattern, this implementation does not save the strategy or include a method to change the strategy within the class. This is because the current version of the application only supports single-time execution. In the future, if the application evolves to handle multiple jobs for sending requests, saving and switching strategies will become useful. However, these changes are minor and can be easily integrated when needed.

Overview

This program is a workload generator designed to simulate HTTP requests to a specified URL. The configuration of the workload is highly customizable, allowing users to specify various parameters such as the mode of operation, the number of threads, the type of threads (virtual or standard), the HTTP request method, and the total number of requests to be made. The program uses an argument parser to set these configurations, ensuring flexibility and ease of use.

Configuration Parameters

• Mode (--m or --mode).

  • Description: Specifies the mode of operation for the workload generator.
  • Default: oneShot
  • Options:
    • oneShot: Executes a single request.
    • throughput: Parallel execution of n requests.
  • Example: --mode oneShot

• URL (--url):

  • Description: The target URL to which the HTTP requests will be sent.
  • Required: Yes
  • Example: --url http://example.com

• Thread Number (--tn or --threadsNumber):

  • Description: Specifies the number of threads to be used for sending requests.
  • Default: 10
  • Example: --threadsNumber 20

• Virtual Threads (--vt or --virtualThread):

  • Description: Indicates whether to use virtual threads.
  • Default: false
  • Note: Cannot be used simultaneously with --thread.
  • Example: --virtualThread

• Standard Threads (--t or --thread):

  • Description: Indicates whether to use standard threads.
  • Default: false
  • Note: Cannot be used simultaneously with --virtualThread.
  • Example: --thread

• Request Method (--r or --requestMethod):

  • Description: Specifies the HTTP request method to be used.
  • Default: GET
  • Options: GET, POST, PUT, DELETE
  • Example: --requestMethod POST

• Request Number (--requestNumber):

  • Description: The total number of requests to be sent.
  • Default: 2000
  • Example: --requestNumber 5000

Error Handling

Duplicated Arguments: If an argument is provided more than once, the program throws an error. Missing Values: If an expected value for an argument is missing, the program throws an error. Invalid Values: If a provided value is not valid (e.g., non-numeric values for numeric arguments, unsupported request methods), the program throws an error. Mutually Exclusive Options: The program ensures that only one type of thread (virtual or standard) is specified; specifying both will result in an error.

Running the application

I have encountered some errors while trying to run latest version of gradle in Inteleji. The more robust way to execute program is utilizing gradle cli. The example of command that build and executes the program:

./gradlew build | ./gradlew run --args="--url https://httpbin.org/anything --vt --mode throughput"