How to achieve dynamic adjustment of Spout and Bolt parallelism in Storm?

The parallelism of Spout and Bolt can be dynamically adjusted in Storm by following these steps:

1. Create a parameter for adjustable parallelism, which can be dynamically adjusted in the code. This parameter can be passed in through a configuration file, command line arguments, or other means.
2. Read and set the parallelism parameter in the initialization method of Spout and Bolt.
3. During the program’s execution, the parallelism parameters can be dynamically adjusted through monitoring tools or interfaces. For example, ZooKeeper can be used to achieve this dynamic adjustment of parallelism.
4. When the parallelism parameter changes, you can make the new parallelism take effect by restarting or reloading the Spout and Bolt.

In conclusion, in order to achieve dynamic adjustment of Spout and Bolt parallelism, it is necessary to set configurable parallelism parameters in the code and be able to monitor and adjust these parameters during runtime.