这个例子定义了一个函数 show_processes()来显示当前正在运行的进程，以及一个函数 kill_process()来杀死具有指定 ID 的进程。show_processes()将成为 MySQL Shell 报告，并将kill_process()成为扩展对象提供的功能。

该代码使用该 方法注册show_processes()为 MySQL Shell 报告。要注册 为 ，代码会检查全局对象和扩展对象是否已经存在，如果不存在则创建并注册它们。然后将该 函数作为成员添加到 扩展对象。 procshell.register_report()kill_process()ext.process.kill()extprocesskill_process()process

插件代码保存为文件 ~/.mysqlsh/plugins/ext/process/init.py. 启动时，MySQL Shell 会遍历plugins 文件夹中的文件夹，找到这个init.py文件，然后执行代码。报告proc和函数kill()已注册并可供使用。如果全局对象ext和扩展对象process尚未被另一个插件注册，则创建并注册它们，否则使用现有对象。

# Define a show_processes function that generates a MySQL Shell report

def show_processes(session, args, options):
  query = "SELECT ID, USER, HOST, COMMAND, INFO FROM INFORMATION_SCHEMA.PROCESSLIST"
  if (options.has_key('command')):
    query += " WHERE COMMAND = '%s'" % options['command']

  result = session.sql(query).execute();
  report = []
  if (result.has_data()):
    report = [result.get_column_names()]
    for row in result.fetch_all():
        report.append(list(row))

  return {"report": report}


# Define a kill_process function that will be exposed by the global object 'ext'

def kill_process(session, id):
  result = session.sql("KILL CONNECTION %d" % id).execute()


# Register the show_processes function as a MySQL Shell report


shell.register_report("proc", "list", show_processes, {"brief":"Lists the processes on the target server.",
                                                       "options": [{
                                                          "name": "command",
                                                          "shortcut": "c",
                                                          "brief": "Use this option to list processes over specific commands."
                                                       }]})


# Register the kill_process function as ext.process.kill()

# Check if global object 'ext' has already been registered
if 'ext' in globals():
    global_obj = ext
else:
    # Otherwise register new global object named 'ext'
    global_obj = shell.create_extension_object()
    shell.register_global("ext", global_obj, 
        {"brief":"MySQL Shell extension plugins."})

# Add the 'process' extension object as a member of the 'ext' global object
try:
    plugin_obj = global_obj.process
except IndexError:
    # If the 'process' extension object has not been registered yet, do it now
    plugin_obj = shell.create_extension_object()
    shell.add_extension_object_member(global_obj, "process", plugin_obj,
        {"brief": "Utility object for process operations."})

# Add the kill_process function to the 'process' extension object as member 'kill'
try:
    shell.add_extension_object_member(plugin_obj, "kill", kill_process, {"brief": "Kills the process with the given ID.",
                                                              "parameters": [
                                                                {
                                                                  "name":"session",
                                                                  "type":"object",
                                                                  "class":"Session",
                                                                  "brief": "The session to be used on the operation."
                                                                },
                                                                {
                                                                  "name":"id",
                                                                  "type":"integer",
                                                                  "brief": "The ID of the process to be killed."
                                                                }
                                                                ]
                                                              })
except Exception as e:
    shell.log("ERROR", "Failed to register ext.process.kill ({0}).".
       format(str(e).rstrip()))

在这里，用户proc使用 MySQL Shell\show命令运行报告，然后使用 ext.process.kill()函数停止列出的进程之一：

mysql-py> \show proc
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+
| ID | USER            | HOST            | COMMAND | INFO                                                                             |
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+
| 66 | root            | localhost:53998 | Query   | PLUGIN: SELECT ID, USER, HOST, COMMAND, INFO FROM INFORMATION_SCHEMA.PROCESSLIST |
| 67 | root            | localhost:34022 | Sleep   | NULL                                                                             |
| 4  | event_scheduler | localhost       | Daemon  | NULL                                                                             |
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+

mysql-py> ext.process.kill(session, 67)
mysql-py> \show proc
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+
| ID | USER            | HOST            | COMMAND | INFO                                                                             |
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+
| 66 | root            | localhost:53998 | Query   | PLUGIN: SELECT ID, USER, HOST, COMMAND, INFO FROM INFORMATION_SCHEMA.PROCESSLIST |
| 4  | event_scheduler | localhost       | Daemon  | NULL                                                                             |
+----+-----------------+-----------------+---------+----------------------------------------------------------------------------------+