Development Environment

The development environment is used by developers to write and test code. It typically includes programming language compilers, integrated development environments (IDEs), and version control systems.

Purpose:

• Writing, debugging, and testing code.
• Performing unit and component tests.
• Developing new features and fixing defects.

What is Middleware Degradation Drill?

Middleware degradation drill refers to the process of intentionally causing middleware failures in production or simulation environments to test the system's emergency response capabilities and fault recovery mechanisms. This helps validate the robustness of existing systems and enhances the operations team's ability to handle and respond to faults.

The dependency:tree command is used to view all dependencies in a project, including direct and transitive dependencies.

Maven Dependency Tree Command

mvn dependency:tree

The DISTINCT keyword is typically used with the SELECT statement to ensure that each row in the query result is unique.

Usage with Multiple Columns

The DISTINCT keyword can be used on multiple columns. In this case, only rows where all specified columns are the same will be considered duplicates and removed.

INSERT IGNORE is an extended syntax in MySQL. When you attempt to insert data into a table, if the data violates uniqueness constraints (such as primary keys or unique indexes), it will ignore the error and continue inserting the remaining data. Compared to the standard INSERT statement, this method prevents insertion failures caused by duplicate data.

Overwrite Update

You can use the _update API to update a single document. This method is suitable for cases where you need to overwrite the entire document.

POST /my_index/_update/1
{
  "doc": {
    "title": "Updated Title",
    "content": "Updated content."
  }
}

Using InheritableThreadLocal

The InheritableThreadLocal class is a subclass of ThreadLocal designed specifically to allow ThreadLocal variables to be inherited by child threads. It automatically passes the ThreadLocal variable value from the parent thread to the child threads.