使用 Python 通过解析 MySQL Binlog 日志分析问题

文章目录

    • 1. 分析目的
    • 2. 代码逻辑
    • 3. 实战分析


1. 分析目的

Binlog 中记录了 MySQL 数据变动,经常用于时间点恢复、数据闪回、分析一些 “奇怪” 的问题。例如是否有大事务,哪张表涉及的更新最多?是否有一些事务没有及时提交,都可以通过分析 binlog 来得到答案。

2. 代码逻辑

收集数据的第一步就是要解析 binlog 文件,binlog 是由事件组成的,例如:GTID 事件、XID 事件、Table Map 事件、DML 事件,只要获得所有的事件,就可以分析到很多东西。每个事件都由两部分组成,事件头 - 事件体,事件头的存储格式是这样的。

类型 占用
timestamp 4 bytes
type_code 1 bytes
server_id 4 bytes
event_length 4 bytes
next_position 4 bytes
flags 2 bytes

一共占 19 bytes 我们通过 header 可以知道事件类型,发生时间、事件长度、下一个事件开始位置。读取头信息后,我们就可以通过 next_position 跳到下一个事件开始的位置,读取事件头,如果遇到 Table_map 事件则表示要开启一个 DML 事务,那么 Table Map 事件中存储的是什么呢?
使用 Python 通过解析 MySQL Binlog 日志分析问题_第1张图片
从 Table Map 中可以获得 DML 要操作的数据库与表信息,这样我们就可以定位到 DML 操作的是哪张表,开启一个事务时,binlog 会先记录 Table_map 事件,涉及到多张表就会有多个 Table_map 事件,然后就是 DML 事件,最后是一个 XID 事件,表示事务提交。脚本通过解析 Query_event 获得事务的起点,解析 Table map 事件获得涉及的表,通过 XID 事件获得事务结束。

3. 实战分析

直接上代码吧~

需要安装 pandas 模块,这个模块处理数据非常方便,如果没有使用过的朋友,建议去把玩下,用好了提升工作效率。

# -*- coding: utf-8 -*-
import sys
import math
import time
import struct
import argparse
import pandas as pd
from datetime import datetime

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 BinlogEvent:
    UNKNOWN_EVENT = 0
    START_EVENT_V3 = 1
    QUERY_EVENT = 2
    STOP_EVENT = 3
    ROTATE_EVENT = 4
    INTVAR_EVENT = 5
    LOAD_EVENT = 6
    SLAVE_EVENT = 7
    CREATE_FILE_EVENT = 8
    APPEND_BLOCK_EVENT = 9
    EXEC_LOAD_EVENT = 10
    DELETE_FILE_EVENT = 11
    NEW_LOAD_EVENT = 12
    RAND_EVENT = 13
    USER_VAR_EVENT = 14
    FORMAT_DESCRIPTION_EVENT = 15
    XID_EVENT = 16
    BEGIN_LOAD_QUERY_EVENT = 17
    EXECUTE_LOAD_QUERY_EVENT = 18
    TABLE_MAP_EVENT = 19
    PRE_GA_WRITE_ROWS_EVENT = 20
    PRE_GA_UPDATE_ROWS_EVENT = 21
    PRE_GA_DELETE_ROWS_EVENT = 22
    WRITE_ROWS_EVENT = 23
    UPDATE_ROWS_EVENT = 24
    DELETE_ROWS_EVENT = 25
    INCIDENT_EVENT = 26
    HEARTBEAT_LOG_EVENT = 27
    IGNORABLE_LOG_EVENT = 28
    ROWS_QUERY_LOG_EVENT = 29
    WRITE_ROWS_EVENT_V2 = 30
    UPDATE_ROWS_EVENT_V2 = 31
    DELETE_ROWS_EVENT_V2 = 32
    GTID_LOG_EVENT = 33
    ANONYMOUS_GTID_LOG_EVENT = 34
    PREVIOUS_GTIDS_LOG_EVENT = 35


class BinlogEventGet(object):
    def __init__(self, binlog_path, outfile_path):
        self.file_handle = open(binlog_path, 'rb')
        # 分析文件导出的位置
        self.outfile_path = outfile_path

    def __del__(self):
        self.file_handle.close()

    def read_table_map_event(self, event_length, next_position):
        """
        fix_part = 8
            table_id : 6bytes
            Reserved : 2bytes
        variable_part:
            database_name_length : 1bytes
            database_name : database_name_length bytes + 1
            table_name_length : 1bytes
            table_name : table_name_length bytes + 1
            cloums_count : 1bytes
            colums_type_array : one byte per column
            mmetadata_lenth : 1bytes
            metadata : .....(only available in the variable length field,varchar:2bytes,text、blob:1bytes,time、timestamp、datetime: 1bytes
                            blob、float、decimal : 1bytes, char、enum、binary、set: 2bytes(column type id :1bytes metadatea: 1bytes))
            bit_filed : 1bytes
            crc : 4bytes
            .........
        :return:
        """
        self.read_bytes(table_map_event_fix_length)
        database_name_length, = struct.unpack('B', self.read_bytes(1))
        database_name, _a, = struct.unpack('{}ss'.format(database_name_length),
                                           self.read_bytes(database_name_length + 1))

        table_name_length, = struct.unpack('B', self.read_bytes(1))
        table_name, _a, = struct.unpack('{}ss'.format(table_name_length), self.read_bytes(table_name_length + 1))

        self.file_handle.seek(next_position, 0)
        return database_name, table_name

    def read_bytes(self, count):
        """
        读取固定 bytes 的数据
        :param count:
        :return:
        """
        return self.file_handle.read(count)

    def main(self):
        if not self.read_bytes(4) == BINLOG_FILE_HEADER:
            print("Error: Is not a standard binlog file format.")
            sys.exit(0)

        # 事务记录字典
        temp_transaction_dict = {
            'id': None,
            'db_name': None,
            'ld_table_name': None,
            'table_set': set(),
            'start_time': None,
            'end_time': None,
            'diff_second': None,
            'event_type': set(),
            'start_position': None,
            'end_position': None
        }

        tem_id = 0
        df = list()
        start_position, end_position = None, None
        print('loading.....')
        while True:
            type_code, event_length, timestamp, next_position = self.read_header()

            # 终止循环判断
            if type_code is None:
                break

            # 事务信息收集逻辑判断
            if type_code == BinlogEvent.QUERY_EVENT:
                thread_id, db_name, info = self.read_query_event(event_length)

                if info == 'BEGIN':
                    temp_transaction_dict['start_position'] = next_position - event_length
                    temp_transaction_dict['start_time'] = timestamp
                    temp_transaction_dict['db_name'] = db_name
                    # print('Time:', timestamp, 'DB:', db_name, 'SQL:', info)
                self.file_handle.seek(next_position, 0)

            elif type_code == BinlogEvent.TABLE_MAP_EVENT:
                with_database, with_table = self.read_table_map_event(event_length, next_position)
                # 只记录最开始的一张表
                if temp_transaction_dict['ld_table_name'] is None:
                    temp_transaction_dict['ld_table_name'] = str(with_table.decode())
                # 一个事务涉及的所有表集合
                temp_transaction_dict['table_set'].add(str(with_table.decode()))

            elif type_code in (BinlogEvent.WRITE_ROWS_EVENT, BinlogEvent.WRITE_ROWS_EVENT_V2):
                # print('INSERT:', type_code, event_length, timestamp, next_position)
                temp_transaction_dict['event_type'].add('INSERT')
                self.file_handle.seek(event_length - binlog_event_header_len, 1)

            elif type_code in (BinlogEvent.UPDATE_ROWS_EVENT, BinlogEvent.UPDATE_ROWS_EVENT_V2):
                # print('UPDATE:', type_code, event_length, timestamp, next_position)
                temp_transaction_dict['event_type'].add('UPDATE')
                self.file_handle.seek(event_length - binlog_event_header_len, 1)

            elif type_code in (BinlogEvent.DELETE_ROWS_EVENT, BinlogEvent.DELETE_ROWS_EVENT_V2):
                # print('DELETE:', type_code, event_length, timestamp, next_position)
                temp_transaction_dict['event_type'].add('DELETE')
                self.file_handle.seek(event_length - binlog_event_header_len, 1)

            elif type_code == BinlogEvent.XID_EVENT:
                # 补充事务结束信息
                temp_transaction_dict['id'] = tem_id
                temp_transaction_dict['end_time'] = timestamp
                temp_transaction_dict['end_position'] = next_position

                _start = datetime.strptime(temp_transaction_dict['start_time'], '%Y-%m-%d %H:%M:%S')
                _end = datetime.strptime(temp_transaction_dict['end_time'], '%Y-%m-%d %H:%M:%S')

                temp_transaction_dict['diff_second'] = (_end - _start).seconds

                df.append(temp_transaction_dict)

                # print(temp_transaction_dict)
                # 收尾
                temp_transaction_dict = {
                    'id': None,
                    'db_name': None,
                    'ld_table_name': None,
                    'table_set': set(),
                    'start_time': None,
                    'end_time': None,
                    'diff_second': None,
                    'event_type': set(),
                    'start_position': None,
                    'end_position': None
                }
                self.file_handle.seek(event_length - binlog_event_header_len, 1)
                tem_id += 1
            else:
                # 如果读取的是一个 header 事件,直接跳过即可。
                self.file_handle.seek(event_length - binlog_event_header_len, 1)

        outfile = pd.DataFrame(df)
        outfile['transaction_size_bytes'] = (outfile['end_position'] - outfile['start_position'])
        outfile["transaction_size"] = outfile["transaction_size_bytes"].map(lambda x: self.bit_conversion(x))
        outfile.to_csv(self.outfile_path, encoding='utf_8_sig')
        print('File Export directory: {}'.format(self.outfile_path))
        print('complete ok!')

    def read_header(self):
        """
        binlog_event_header_len = 19
        timestamp : 4bytes
        type_code : 1bytes
        server_id : 4bytes
        event_length : 4bytes
        next_position : 4bytes
        flags : 2bytes
        """
        read_byte = self.read_bytes(binlog_event_header_len)

        if read_byte:
            result = struct.unpack('=IBIIIH', read_byte)
            type_code, event_length, timestamp, next_position = result[1], result[3], result[0], result[4]

            return type_code, event_length, time.strftime('%Y-%m-%d %H:%M:%S',
                                                          time.localtime(
                                                              timestamp)), next_position
        else:
            return None, None, None, None

    def read_query_event(self, event_length=None):
        """
        fix_part = 13:
                thread_id : 4bytes
                execute_seconds : 4bytes
                database_length : 1bytes
                error_code : 2bytes
                variable_block_length : 2bytes
            variable_part :
                variable_block_length = fix_part.variable_block_length
                database_name = fix_part.database_length
                sql_statement = event_header.event_length - 19 - 13 - variable_block_length - database_length - 4
        """
        read_byte = self.read_bytes(binlog_event_fix_part)
        fix_result = struct.unpack('=IIBHH', read_byte)
        thread_id = fix_result[0]
        self.read_bytes(fix_result[4])
        read_byte = self.read_bytes(fix_result[2])
        database_name, = struct.unpack('{}s'.format(fix_result[2]), read_byte)
        statement_length = event_length - binlog_event_fix_part - binlog_event_header_len \
                           - fix_result[4] - fix_result[2] - binlog_quer_event_stern
        read_byte = self.read_bytes(statement_length)
        _a, sql_statement, = struct.unpack('1s{}s'.format(statement_length - 1), read_byte)
        return thread_id, database_name.decode(), sql_statement.decode()

    @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__':
    parser = argparse.ArgumentParser(description='A piece of binlog analysis code.')
    parser.add_argument('--binlog', type=str, help='Binlog file path.', default=None)
    parser.add_argument('--outfile', type=str, help='Analyze the file export directory.', default=None)
    args = parser.parse_args()

    if not args.binlog or not args.outfile:
        parser.print_help()
        sys.exit(0)

    binlog_show = BinlogEventGet(args.binlog, args.outfile)
    binlog_show.main()
➜  Desktop python3 BinlogShow.py --help
usage: BinlogShow.py [-h] [--binlog BINLOG] [--outfile OUTFILE]

A piece of binlog analysis code.

optional arguments:
  -h, --help         show this help message and exit
  --binlog BINLOG    Binlog file path.
  --outfile OUTFILE  Analyze the file export directory.
➜  Desktop

指定 binlog 文件目录和导出分析文件目录即可。

➜  Desktop python3 BinlogShow.py --binlog=/Users/cooh/Desktop/mysql-bin.009549 --outfile=/Users/cooh/Desktop/binlogshow.csv
loading.....
File Export directory: /Users/cooh/Desktop/binlogshow.csv
complete ok!

运行完成后就会得到程序解析后的信息,我们根据这份文件,写一些分析代码即可。
使用 Python 通过解析 MySQL Binlog 日志分析问题_第2张图片

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