基于Python和Xtrbackup的自动化备份与还原实现

xtrabackup是一个MySQL备份还原的常用工具，实际使用过程应该都是shell或者python封装的自动化脚本，尤其是备份。
对还原来说，对于基于完整和增量备份的还原，还原差异备份需要指定增量备份等等一系列容易出错的手工操作，以及binlog的还原等，如果纯手工操作的话非常麻烦。
即便是你记性非常好，对xtrabackup非常熟悉，纯手工操作的话，非常容易出错，其实也上网找过，还原没有发现太好用的自动化还原脚本。
于是就自己用Python封装了xtrabackup备份和还原的过程，可以做到自动化备份，基于时间点的自动化还原等等。

需要对xtrabackup有一定的了解，包括流式备份，压缩备份，Xtrabackup还原，mysqlbinlog还原等等。

备份

1，基于xtrabackup的流式压缩备份。
2，周六/或者任意时间的第一次备份为完整备份，其他时间为基于上一次备份的增量备份。
3，将备份开始时间，结束时间，备份路径等信息写入一个日志文件，方便后续自动化还原的时候解析。

效果如下：不管是什么时候，第一次必须为完整备份，然后根据上述规则，继续执行备份的话为基于最新一次备份的增量备份，每备份完成后生成修改备份日志列表信息。

实现：

 # -*- coding: utf-8 -*-
 import os
 import time
 import datetime
 import sys
 import socket
 import shutil
 import logging

 logging.basicConfig(level=logging.INFO
                     #handlers={logging.FileHandler(filename='backup_log_info.log', mode='a', encoding='utf-8')}
                     )

 host = "127.0.0.1"
 port = ""
 user = "root"
 password = "root"
 cnf_file = "/usr/local/mysql57_data/mysql7000/etc/my.cnf"
 backup_dir = "/usr/local/backupdata"
 backupfilelist = os.path.join(backup_dir,"backupfilelist.log")
 backup_keep_days = 15

 #获取备份类型，周六进行完备，平时增量备份，如果没有全备，执行完整备份
 def get_backup_type():
     backup_type = None
     if os.path.exists(backupfilelist):
         with open(backupfilelist, 'r') as f:
             lines = f.readlines()
             if(lines):
                 last_line = lines[-1] #get last backup name
                 if(last_line):
                     if(time.localtime().tm_wday==6):
                         backup_type = "full"
                     else:
                         backup_type = "incr"
                 else:
                     backup_type = "full"
             else:
                 backup_type = "full"
     else:
         #full backup when first backup
         open(backupfilelist, "a").close()
         backup_type = "full"
     return backup_type

 #获取最后一次备份信息
 def get_last_backup():
     last_backup = None
     if os.path.exists(backupfilelist):
         with open(backupfilelist, 'r') as f:
             lines = f.readlines()
             last_line = lines[-1]  # get last backup name
             if (last_line):
                 last_backup = os.path.join(backup_dir, last_line.split("|")[-1])
     return last_backup.replace("\n","")

 #探测实例端口号
 def get_mysqlservice_status():
     mysql_stat = 0
     s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
     result = s.connect_ex((host, int(port)))
     #port os open
     if (result == 0):
         mysql_stat = 1
     return mysql_stat

 #清理过期的历史备份信息
 def clean_expired_file():
     for backup_name in os.listdir(backup_dir):
         if os.path.isdir(backup_name):
             bak_datetime = datetime.datetime.strptime(backup_name.replace("_full","").replace("_incr",""), '%Y%m%d%H%M%S')
             if(bak_datetime<datetime.datetime.now() - datetime.timedelta(days=backup_keep_days)):
                 shutil.rmtree(os.path.join(backup_dir, backup_name))

 #完整备份
 def full_backup(backup_file_name):
     os.system("[ ! -d {0}/{1} ] && mkdir -p {0}/{1}".format(backup_dir,backup_file_name))
     logfile = os.path.join(backup_dir, "{0}/{1}/backuplog.log".format(backup_dir,backup_file_name))
     backup_commond = ''' innobackupex --defaults-file={0} --no-lock {1}/{6}  --user={2} --password={3} --host="{4}" --port={5} --tmpdir={1}/{6} --stream=xbstream --compress  --compress-threads=8 --parallel=4  --extra-lsndir={1}/{6}  > {1}/{6}/{6}.xbstream 2>{7} '''.\
                     format(cnf_file,backup_dir,user,password,host,port,backup_file_name,logfile)
     execute_result = os.system(backup_commond)
     return execute_result

 #增量备份
 def incr_backup(backup_file_name):
     os.system("[ ! -d {0}/{1} ] && mkdir -p {0}/{1}".format(backup_dir, backup_file_name))
     current_backup_dir = "{0}/{1}".format(backup_dir, backup_file_name)
     logfile = os.path.join(backup_dir, "{0}/{1}/backuplog.log".format(backup_dir, backup_file_name))
     #增量备份基于上一个增量/完整备份
     incremental_basedir = get_last_backup()
     backup_commond = '''innobackupex --defaults-file={0} --no-lock  {6}  --user={2} --password={3} --host={4} --port={5} --stream=xbstream --tmpdir={6} --compress --compress-threads=8 --parallel=4   --extra-lsndir={6} --incremental --incremental-basedir={7} 2> {8} > {6}/{9}.xbstream '''\
                     .format(cnf_file,backup_dir,user,password,host,port,current_backup_dir,incremental_basedir,logfile,backup_file_name)
     # print(backup_commond)
     execute_result = os.system(backup_commond)
     return execute_result

 #刷新binlog，意义不大，原本计划在完整备份之后执行一个binlog的切换，暂时弃用
 def flush_log():
     flush_log_commond = ''' mysql -h${0} -u${1} - p${2} -P${1}  mysql - e"flush logs" '''.format(user,password,host,port)
     os.system(flush_log_commond)

 if __name__ == '__main__':
     mysql_stat = get_mysqlservice_status()
     backup_type = get_backup_type()
     if mysql_stat <= 0 :
         logging.info("mysql instance is inactive,backup exit")
         sys.exit(1)
     try:
         start_time = datetime.datetime.now().strftime('%Y%m%d%_H%M%S')
         logging.info(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')+"--------start backup")
         #flush_log()
         backup_file_name = start_time
         execute_result = None
         if(backup_type == "full"):
             backup_file_name = backup_file_name+"_full"
             logging.info("execute full backup......")
             execute_result = full_backup(backup_file_name)
             if (execute_result == 0):
                 logging.info(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S') + "--------begin cleanup history backup")
                 logging.info("execute cleanup backup history......")
                 clean_expired_file()
                 logging.info(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S') + "--------finsh cleanup history backup")
         else:
             backup_file_name = backup_file_name + "_incr"
             logging.info("execute incr backup......")
             execute_result = incr_backup(backup_file_name)
         if(execute_result==0):
             finish_time = datetime.datetime.now().strftime('%Y%m%d%_H%M%S')
             backup_info = start_time+"|"+finish_time+"|"+start_time+ "_" + backup_type
             with open(backupfilelist, 'a+') as f:
                 f.write(backup_info + '\n')
             logging.info(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')+"--------finish backup")
         else:
             logging.info(datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S') + "--------xtrabackup failed.please check log")
     except:
         raise
         sys.exit(1)

还原

说直白一点，以这里的基于时间点或者是position的还原，就是一个不断找文件的过程，
1，首先任何还原，都需要一个创建于还原点前的完整备份。
2，基于上述完整备份，利用还原的时间点与xtrbackup的备份日志去做对比来获取所需的增量备份（0个或者1个或者多个）。
3，基于上面两步找到的（完整+增量）备份，利用最后一个备份的position，用于第一个binlog还原时指定start-position，
　  同时利用binlog的最后修改时间与还原的时间点对比，决定使用那些binlog，同时最后一个binlog要指定stop-datime= 还原的时间点

1，如何还原时间点的最新的一个完整备份
备份的时候维护一个备份信息，如下,这里是backfilelist.log，包括备份开始时间，结束时间，备份类型，备份路径等。
可以根据备份开始时间，找到第一个早于还原时间点的完整备份　　

2，如果找到恢复所需要的差异备份
同1，从完整备份开始，依次向后找各个增量备份，直到最后一个早于还原时间点的差异备份，可能有一个或者多个

3，如何找到差异备份之后，需要哪些binlog
基于binlog文件自身的最后修改时间属性信息，从2中找到的最后一个差异备份的时间，开始向后依次找binlog，可能有一个或者多个　

自动还原demo

如下是一个基于时间点来还原数据库的demo，没写入两条数据，执行一次备份（上述备份会自动区分完整备份或者差异备份）
三次备份之后，继续写两条数据，flush logs,然后继续分两次分别写两条数据，目的是将数据分散到不同的binlog中，最后删除全部数据
然后基于删除数据之前的时间点来自动生成还原数据库的shell，执行shell即可达到还原数据库的目的。

如下执行基于时间点的rextrabackup.py文件之后，时间点为"2019-08-01 18:50:59"，也就是发生删除操作的前一个时间点，来生成的还原信息。
其实只需要重定向到一个shell文件中，执行shell文件即可自动化还原，或者直接在python脚本中执行这些命令，即可自动化完成还原操作。
这里为了显示，打印了出来。

可以发现，基于时间点的还原，找到的文件是预期的：
1个完整备份，2个增量备份，2个binlog日志中的一部分数据，
其中binlog日志还原的start-position成功地衔接到最后一个增量备份的position，同时最后一个binlog日志的还原停留在指定的时间点。

自动生成的shell还原代码

################uncompress backup file###################
innobackupex --apply-log --redo-only /temp/restoretmp/20190801184134_full
innobackupex --apply-log --redo-only /temp/restoretmp/20190801184134_full --incremental-dir=/temp/restoretmp/20190801184335_inc
innobackupex --apply-log --redo-only /temp/restoretmp/20190801184134_full --incremental-dir=/temp/restoretmp/20190801184518_inc
innobackupex --apply-log /temp/restoretmp/20190801184134_full
################stop mysql service###################
systemctl stop mysqld_7000
####################backup current database file###########################
mv /usr/local/mysql57_data/mysql7000/data /usr/local/mysql57_data/mysql7000/data_20190801185855
mkdir /usr/local/mysql57_data/mysql7000/data
chown -R mysql.mysql /usr/local/mysql57_data/mysql7000/data
################restore backup data###################
innobackupex --defaults-file=/usr/local/mysql57_data/mysql7000/etc/my.cnf --copy-back --rsync /temp/restoretmp/20190801184134_full
chown -R mysql.mysql /usr/local/mysql57_data/mysql7000/data
################stop mysql service###################
systemctl start mysqld_7000
################restore data from binlog###################
cd /usr/local/mysql57_data/mysql7000/log/bin_log
mysqlbinlog mysql_bin_1300.000001  --skip-gtids=true --start-position=982 | mysql mysql -h127.0.0.1 -uroot -proot -P7000
mysqlbinlog mysql_bin_1300.000002  --skip-gtids=true --stop-datetime="2019-08-01 18:50:59" | mysql -h127.0.0.1 -uroot -proot -P7000

日志信息

实现

# -*- coding: utf-8 -*-
import os
import time
import datetime
import sys
import socket
import logging

logging.basicConfig(level=logging.INFO
                    #handlers={logging.FileHandler(filename='restore_log_info.log', mode='a', encoding='utf-8')}
                    )

host = "127.0.0.1"
port = ""
user = "root"
password = "root"
instance_name = "mysqld_7000"
stop_at = "2019-08-01 18:50:59"
cnf_file = "/usr/local/mysql57_data/mysql7000/etc/my.cnf"
backup_dir = "/usr/local/backupdata/"
dest_dir = "/temp/restoretmp/"
xtrabackuplog_name = "backuplog.log"
backupfilelist = os.path.join(backup_dir,"backupfilelist.log")

#根据key值，获取MySQL配置文件中的value
def get_config_value(key):
    value = None
    if not key:
        return value
    if os.path.exists(cnf_file):
        with open(cnf_file, 'r') as f:
            for line in f:
                if (line.split("=")[0]):
                    if(line[0:1]!="#" and line[0:1]!="["):
                        if (key==line.split("=")[0].strip()):
                            value =line.split("=")[1].strip()
    return value

def stop_mysql_service():
    print("################stop mysql service###################")
    print("systemctl stop {}".format(instance_name))

def start_mysql_service():
    print("################stop mysql service###################")
    print("systemctl start {0}".format(instance_name))

#返回备份日志中的最新的一个早于stop_at时间的完整备份，以及其后面的增量备份
def get_restorefile_list():
    list_backup = []
    list_restore_file = []
    if os.path.exists(backupfilelist):
        with open(backupfilelist, 'r') as f:
            lines = f.readlines()
            for line in lines:
                list_backup.append(line.replace("\n",""))
    if (list_backup):
        for i in range(len(list_backup) - 1, -1, -1):
            list_restore_file.append(list_backup[i])
            backup_name = list_backup[i].split("|")[2]
            if "full" in backup_name:
                full_backup_time = list_backup[i].split("|")[1]
                if(stop_at<full_backup_time):
                    break
                else:
                    list_restore_file = None
    #restore file in the list_restore_log
    list_restore_file.reverse()
    return list_restore_file

#解压缩需要还原的备份文件，包括一个完整备份以及N个增量备份（N>=0）
def uncompress_backup_file():
    print("################uncompress backup file###################")
    list_restore_backup = get_restorefile_list()

    #如果没有生成时间早于stop_at的完整备份，无法恢复，退出
    if not list_restore_backup:
        raise("There is no backup that can be restored")
        exit(1)

    for restore_log in list_restore_backup:
        #解压备份文件
        backup_name = restore_log.split("|")[2]
        backup_path = restore_log.split("|")[2]
        backup_full_name = os.path.join(backup_dir,backup_path,backup_name)
        backup_path = os.path.join(backup_dir,restore_log.split("|")[-1])
        #print('''[ ! -d {0} ] && mkdir -p {0}'''.format(os.path.join(dest_dir,backup_name)))
        os.system('''[ ! -d {0} ] && mkdir -p {0}'''.format(os.path.join(dest_dir,backup_name)))
        #print("xbstream -x < {0}.xbstream -C {1}".format(backup_full_name,os.path.join(dest_dir,backup_name)))
        os.system("xbstream -x < {0}.xbstream -C {1}".format(backup_full_name,os.path.join(dest_dir,backup_name)))
        #print("cd {0}".format(os.path.join(dest_dir,backup_name)))
        os.system("cd {0}".format(os.path.join(dest_dir,backup_name)))
        #print('''for f in `find {0}/ -iname "*\.qp"`; do qpress -dT4 $f  $(dirname $f) && rm -f $f; done '''.format(os.path.join(dest_dir,backup_name)))
        os.system('''for f in `find {0}/ -iname "*\.qp"`; do qpress -dT4 $f  $(dirname $f) && rm -f $f; done'''.format(os.path.join(dest_dir,backup_name)))

        current_backup_begin_time = None
        current_backup_end_time = None
        #比较当前备份的结束时间和stop_at,如果当前备份开始时间小于stop_at并且结束时间大于stop_at，解压缩备份结束
        with open(os.path.join(dest_dir,backup_name,"xtrabackup_info"), 'r') as f:
            for line in f:
                if line and line.split("=")[0].strip()=="start_time":
                    current_backup_begin_time = line.split("=")[1].strip()
                if line and line.split("=")[0].strip()=="end_time":
                    current_backup_end_time = line.split("=")[1].strip()
        #按照stop_at时间点还原的最后一个数据库备份,结束从第一个完整备份开始的解压过程
        if current_backup_begin_time<=stop_at<=current_backup_end_time:
            break

    #返回最后一个备份文件，需要备份文件中的xtrabackup_info，解析出当前备份的end_time，从而确认需要哪些binlog
    return backup_name

#根据返回最后一个备份文件，需要备份文件中的xtrabackup_info，结合stop_at，确认需要还原的binlog文件，以及binlog的position信息
def restore_database_binlog(last_backup_file):
    print("################restore data from binlog###################")
    binlog_dir = get_config_value("log-bin")
    if not (backup_dir):
        binlog_dir = get_config_value("log_bin")
    print("cd {0}".format(os.path.dirname(binlog_dir)))

    last_backup_file =os.path.join(dest_dir,last_backup_file,"xtrabackup_info")
    #parse backuplog.log and get binlog name and position

    backup_position_binlog_file = None
    backup_position = None
    with open(last_backup_file, 'r') as f:
        lines = f.readlines()
        for line in lines:
            if "binlog_pos = filename " in line:
                backup_position_binlog_file = line.replace("binlog_pos = filename ", "").split(",")[0]
                backup_position_binlog_file = backup_position_binlog_file.replace("'", "")
                backup_position = line.replace("binlog_pos = filename ", "").split(",")[1].strip()
                backup_position = backup_position.split(" ")[1].replace("'", "")
                pass
            else:
                continue
        # /usr/local/mysql57_data/mysql8000/log/bin_log/mysql_bin_1300
        binlog_config = get_config_value("log-bin")
        binlog_path = os.path.dirname(binlog_config)
        binlog_files = os.listdir(binlog_path)

        #如果没有找到binlog，忽略binlog的还原
        if not binlog_files:
            exit(1)

        #对binlog文件排序，按顺序遍历binlog，获取binlog的最后的修改时间，与stop_at做对比，判断还原的过程是否需要某个binlogfile
        binlog_files.sort()

        binlog_files_for_restore = []
        # 恢复数据库的指定时间点
        stop_at_time = datetime.datetime.strptime(stop_at, '%Y-%m-%d %H:%M:%S')
        for binlog in binlog_files:
            if (".index" in binlog or "relay" in binlog):
                continue

            #保留最后一个备份中的binlog，以及其后面的binlog，这部分binlog会在还原的时候用到
            if (int(binlog.split(".")[-1]) >= int(backup_position_binlog_file.split(".")[-1])):
                binlog_files_for_restore.append(binlog)

        binlog_file_count = 0
        #第一个文件，从上最后一个差异备份的position位置开始，最后一个文件，需要stop_at到指定的时间
        for binlog in binlog_files_for_restore:
            if not os.path.isdir(binlog):
                #binlog物理文件的最后修改时间
                binlog_file_updatetime = datetime.datetime.strptime(time.strftime('%Y-%m-%d %H:%M:%S', time.localtime(os.stat(binlog_path+"/"+binlog).st_mtime)),'%Y-%m-%d %H:%M:%S')
                #判断binlog的生成时间，是否大于stop_at，对于修改时间大于stop_at的日志，需要全部还原，不需要stop_at指定截止点
                if  stop_at_time > binlog_file_updatetime :
                    if (binlog_file_count < 1):
                        if (len(binlog_files_for_restore) == 1):
                            # 找到差异备份之后的第一个binlog，需要根据差异备份的position，来过来第一个binlog文件
                            restore_commond = '''mysqlbinlog {0}  --skip-gtids=true --start-position={1}  --stop-datetime="{2}" | mysql mysql -h{3} -u{4} -p{5} -P{6}''' \
                                .format(binlog, backup_position, stop_at, host, user, password, port)
                            print(restore_commond)
                            binlog_file_count = binlog_file_count + 1
                        else:
                            # 找到差异备份之后的第一个binlog，需要根据差异备份的position，来过来第一个binlog文件
                            restore_commond = '''mysqlbinlog {0}  --skip-gtids=true --start-position={1} | mysql mysql -h{2} -u{3} -p{4} -P{5}''' \
                                .format(binlog, backup_position, host, user, password, port)
                            print(restore_commond)
                            binlog_file_count = binlog_file_count + 1
                    else:
                        # 从第二个文件开始，binlog需要全部还原
                        restore_commond = '''mysqlbinlog {0}  --skip-gtids=true  | mysql mysql -h{1} -u{2} -p{3} -P{4}''' \
                            .format(binlog, host, user, password, port)
                        print(restore_commond)
                        binlog_file_count = binlog_file_count + 1
                else:
                      if (binlog_file_count < 1):
                          restore_commond = '''mysqlbinlog {0}  --skip-gtids=true --start-position={1} --stop-datetime={2} | mysql -h{3} -u{4} -p{5} -P{6}'''.format(binlog, backup_position,stop_at,host,user,password,port)
                          print(restore_commond)
                          binlog_file_count = binlog_file_count + 1
                      else:
                          if (binlog_file_count >= 1):
                              restore_commond = '''mysqlbinlog {0}  --skip-gtids=true --stop-datetime="{1}" | mysql -h{2} -u{3} -p{4} -P{5}'''.format(binlog, stop_at,host,user,password,port)
                              print(restore_commond)
                              binlog_file_count = binlog_file_count + 1
                              break

def apply_log_for_backup():
    list_restore_backup = get_restorefile_list()
    start_flag = 1
    full_backup_path = None

    for current_backup_file in list_restore_backup:
        #解压备份文件
        current_backup_name = current_backup_file.split("|")[2]
        current_backup_fullname = os.path.join(dest_dir, current_backup_name)
        if(start_flag==1):
            full_backup_path = current_backup_fullname
            start_flag = 0
            print("innobackupex --apply-log --redo-only {0}".format(full_backup_path))
        else:
            print("innobackupex --apply-log --redo-only {0} --incremental-dir={1}".format(full_backup_path,current_backup_fullname))
    #apply_log for full backup at last(remove --read-only parameter)
    print("innobackupex --apply-log {0}".format(full_backup_path))

def restore_backup_data():
    print("####################backup current database file###########################")
    datadir_path = get_config_value("datadir")
    print("mv {0} {1}".format(datadir_path,datadir_path+"_"+ datetime.datetime.now().strftime('%Y%m%d%H%M%S')))
    print("mkdir {0}".format(datadir_path))
    print("chown -R mysql.mysql {0}".format(datadir_path))
    print("################restore backup data###################")
    list_restore_backup = get_restorefile_list()
    full_restore_path= dest_dir + list_restore_backup[0].split("|")[-1].replace(".xbstream","")
    print("innobackupex --defaults-file={0} --copy-back --rsync {1}".format(cnf_file,full_restore_path))
    print("chown -R mysql.mysql {0}".format(datadir_path))

def restore_database():
    #解压缩需要还原的备份文件
    last_backup_file_path = uncompress_backup_file()
    #对备份文件apply-log
    apply_log_for_backup()
    #停止mysql服务
    stop_mysql_service()
    #恢复备份
    restore_backup_data()
    #启动MySQL服务
    start_mysql_service()
    #从binlog中恢复数据
    restore_database_binlog(last_backup_file_path)

if __name__ == '__main__':
    restore_database()

最后不要忘了清理战场：
1，解压缩的备份文件还留在指定的路径中，
2，还原之前备份的data文件，以data_日期命名的文件，也没有清理

挤时间写出来的，粗略测了一下没有问题，以实现功能为主，没有进一步封装，后续会以此为基础进行优化。