什么是mysql增量同步

import pymysqlreplication

class MyEventHandler(pymysqlreplication.RowEvent):
    def __init__(self, output_queue):
        self.output_queue = output_queue

    def on_row(self, event):
        if isinstance(event, pymysqlreplication.events.UpdateRowsEvent):
            for row in event.rows:
                self.output_queue.put(("update", row["values"], row["after_values"]))

def start_binlog_listener(host, port, user, password, output_queue):
    stream = pymysqlreplication.BinLogStreamReader(
        connection_settings={
            "host": host,
            "port": port,
            "user": user,
            "passwd": password,
        },
        server_id=100,
        only_events=[pymysqlreplication.events.UpdateRowsEvent],
        blocking=True,
        only_tables=['your_table_name']
    )

    event_handler = MyEventHandler(output_queue)
    for event in stream:
        event_handler.on_event(event)

# 示例用法
from queue import Queue

output_queue = Queue()
start_binlog_listener('localhost', 3306, 'your_user', 'your_password', output_queue)

while True:
    action, before, after = output_queue.get()
    print(f"Action: {action}, Before: {before}, After: {after}")