MySQL--Skip GTID CAP

import os

script_file = "./skip_file.sql"


def write_script(script_content):
    file_handle = open(script_file, 'a+')
    file_handle.writelines(script_content + "\n")
    file_handle.close()


def delete_script_file():
    if os.path.exists(script_file):
        os.remove(script_file)


def get_skip_script_list(master_uuid, start_tran_id, end_tran_id):
    script_list = []
    current_tran_id = start_tran_id
    while current_tran_id <= end_tran_id:
        current_script = """
SET @@SESSION.GTID_NEXT= '{master_uuid}:{tran_id}';
BEGIN; COMMIT;
""".format(
            master_uuid=master_uuid,
            tran_id=current_tran_id
        )
        current_tran_id = current_tran_id + 1
        script_list.append(current_script)
    script_list.append("SET SESSION GTID_NEXT = AUTOMATIC;")
    return script_list


def main():
    master_uuid = "0275e614-b4b1-11e7-8f24-b8ca3a6fcb25"
    start_tran_id = 1
    end_tran_id = 177
    script_list = get_skip_script_list(master_uuid, start_tran_id, end_tran_id)
    write_script("\n".join(script_list))


if __name__ == '__main__':
    main()

 

当从库误执行一些SQL时或其他原因导致主从上的gtid集合不一致时，可以通过这种方式生成一些空事务，避免主从切换后发生从库无法获取新主库已purge掉的binlog而中断。