MySQL如何查询Binlog 生成时间

目录

• 前言
• 脚本介绍
• 使用案例
• 1. 查询 binlog index 文件
• 2. 使用脚本查询时间

前言

本篇文章介绍如何查询 Binlog 的生成时间。云上 RDS 有日志管理，但是自建实例没有，该脚本可用于自建实例闪回定位 Binlog 文件。

脚本介绍

直接上代码吧～

通过读取 Binlog FORMAT_DESCRIPTION_EVENT header 时间戳来实现读取 Binlog 生产时间。

# -*- coding: utf-8 -*-
import os
import sys
import math
import time
import struct
import argparse

binlog_quer_event_stern = 4
binlog_event_fix_part = 13
table_map_event_fix_length = 8
BINLOG_FILE_HEADER = b'\xFE\x62\x69\x6E'
binlog_event_header_len = 19

class BinlogTimestamp(object):
    def __init__(self, index_path):
        self.index_path = index_path

    def main(self):
        binlog_info_list = list()
        for file_path in self.reed_index_file():
            result = self.read_binlog_pos(file_path)
            binlog_info_list.append({
                'file_name': result[0],
                'binlog_size': result[2],
                'start_time': result[1]
            })
        # print
        i = 0

        while len(binlog_info_list) > i:
            if i + 1 == len(binlog_info_list):
                end_time = 'now'
            else:
                end_time = binlog_info_list[i + 1]['start_time']

            binlog_info_list[i]['end_time'] = end_time
            print(binlog_info_list[i])
            i += 1

    def read_binlog_pos(self, binlog_path):
        binlog_file_size = self.bit_conversion(os.path.getsize(binlog_path))
        file_name = os.path.basename(binlog_path)
        with open(binlog_path, 'rb') as r:
            # read BINLOG_FILE_HEADER
            if not r.read(4) == BINLOG_FILE_HEADER:
                print("Error: Is not a standard binlog file format.")
                sys.exit(0)

            # read binlog header FORMAT_DESCRIPTION_EVENT
            read_byte = r.read(binlog_event_header_len)
            result = struct.unpack('=IBIIIH', read_byte)
            type_code, event_length, event_timestamp, next_position = result[1], result[3], result[0], result[4]
            binlog_start_time = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(event_timestamp))

        return file_name, binlog_start_time, binlog_file_size

    def reed_index_file(self):
        """
        读取 mysql-bin.index 文件
        select @@log_bin_index;
        :return:
        """
        with open(self.index_path) as r:
            content = r.readlines()

        return [x.replace('\n', '') for x in content]

    @staticmethod
    def bit_conversion(size, dot=2):
        size = float(size)
        if 0 <= size < 1:
            human_size = str(round(size / 0.125, dot)) + ' b'
        elif 1 <= size < 1024:
            human_size = str(round(size, dot)) + ' B'
        elif math.pow(1024, 1) <= size < math.pow(1024, 2):
            human_size = str(round(size / math.pow(1024, 1), dot)) + ' KB'
        elif math.pow(1024, 2) <= size < math.pow(1024, 3):
            human_size = str(round(size / math.pow(1024, 2), dot)) + ' MB'
        elif math.pow(1024, 3) <= size < math.pow(1024, 4):
            human_size = str(round(size / math.pow(1024, 3), dot)) + ' GB'
        elif math.pow(1024, 4) <= size < math.pow(1024, 5):
            human_size = str(round(size / math.pow(1024, 4), dot)) + ' TB'
        elif math.pow(1024, 5) <= size < math.pow(1024, 6):
            human_size = str(round(size / math.pow(1024, 5), dot)) + ' PB'
        elif math.pow(1024, 6) <= size < math.pow(1024, 7):
            human_size = str(round(size / math.pow(1024, 6), dot)) + ' EB'
        elif math.pow(1024, 7) <= size < math.pow(1024, 8):
            human_size = str(round(size / math.pow(1024, 7), dot)) + ' ZB'
        elif math.pow(1024, 8) <= size < math.pow(1024, 9):
            human_size = str(round(size / math.pow(1024, 8), dot)) + ' YB'
        elif math.pow(1024, 9) <= size < math.pow(1024, 10):
            human_size = str(round(size / math.pow(1024, 9), dot)) + ' BB'
        elif math.pow(1024, 10) <= size < math.pow(1024, 11):
            human_size = str(round(size / math.pow(1024, 10), dot)) + ' NB'
        elif math.pow(1024, 11) <= size < math.pow(1024, 12):
            human_size = str(round(size / math.pow(1024, 11), dot)) + ' DB'
        elif math.pow(1024, 12) <= size:
            human_size = str(round(size / math.pow(1024, 12), dot)) + ' CB'
        else:
            raise ValueError('bit_conversion Error')
        return human_size

if __name__ == '__main__':
    file_name = sys.argv[1]

    bt = BinlogTimestamp(file_name)
    bt.main()

使用案例

1. 查询 binlog index 文件

2. 使用脚本查询时间

脚本上传到 MySQL 服务器后，指定 binlog index 文件位置即可：

python check_bintime.py /data/mysql_57/logs/mysql-bin.index

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