pt-online-schema-change 脚本化

mysql在线更改表可用工具 pt-online-schema-change 更改，或者用gh-ost更改。pt-online-schema-change 在原表创建索引，跟踪新插入的数据。gh-ost则根据日志应用到更改后的表。

下面把pt-online-schema-change封装为脚本化

#!/usr/bin/python
#coding:utf8# 使用方法 例如 python mysql_osc.py  -s 192.168.x.x -p 3306 -d test  -t test  -a 'add column `name16` varchar(200)' 
import sys
import os
import commands
import argparse
##自定义mysql链接类
from mysqlmodel  import mysqlconn   
general_user = cf.get('mysqlinfo','user')
general_passwd = cf.get('mysqlinfo','passwd')

def osc(server_ip,server_port,dbname,tabname,ddlstmt):
    try:
        conn=mysqlconn(server_ip,server_port)
        sql1="SELECT COUNT(1) as dbcount FROM information_schema.tables WHERE TABLE_SCHEMA  not in ('mysql','performance_schema','information_schema','sys','test') and TABLE_SCHEMA='%s' and TABLE_NAME='%s';" % (dbname,tabname)
        sql2="select COUNT(1) as inxcount  from information_schema.STATISTICS where TABLE_SCHEMA='%s' and TABLE_NAME='%s' AND NON_UNIQUE=0 ;" % (dbname,tabname)
        sql3="show slave status"
        check_table=conn.myquery(sql1)
        check_index=conn.myquery(sql2)
        check_slave=conn.myquery(sql3)
        if len(check_slave)!=0:
            print "%s:%s 不是主节点,更改失败" %  (server_ip,server_port)
            sys.exit()
        if check_table[0]["dbcount"]!=1:
            print "表名 %s.%s 不存在" % (dbname,tabname)
            sys.exit()
        if check_index[0]["inxcount"]<1:
            print "表名 %s.%s 不存在唯一索引" % (dbname,tabname)
            sys.exit()
    except  Exception as error:
        print "error: %s " % (error)
        print "mysql 链接错误"
        sys.exit()
    try:
        cmd = """/usr/local/toolkit/bin/pt-online-schema-change p='%s',u=%s,A=utf8mb4,h='%s',P=%s,D=%s,t=%s --alter='%s'  --execute """  % (general_passwd,general_user,server_ip,server_port,dbname,tabname,ddlstmt)
        #print cmd
        status=commands.getstatusoutput(cmd)
        mystatus=status[1]
        if status[1].find("Successfully altered")>0 and status[0]==0:
            mystatus="Successfully altered"
        return mystatus
    except  Exception as error:
        print "error: %s " % (error)
        return "执行失败"
if __name__ == '__main__':
    #参数:
    parser = argparse.ArgumentParser(description='请输入 -s ip , -p 端口 ,-d 数据库名称,-t 表名, -a 更改语句')
    parser.add_argument('-s','--host', type=str,required=True,help="数据库地址")
    parser.add_argument('-p','--port', type=int,required=True,help="数据库端口")
    parser.add_argument('-d','--db', type=str,required=True,help="数据库名")
    parser.add_argument('-t','--table', type=str,required=True,help="表名")
    parser.add_argument('-a','--ddlstmt', type=str,required=True,help="更改语句")
    args = parser.parse_args()
    server_ip = args.host
    server_port = args.port
    dbname = args.db
    tabname = args.table
    ddlstmt = args.ddlstmt
    if server_ip=="" or server_port=="" or dbname=="" or tabname=="" or ddlstmt=="":
        print "输入完整信息"
        sys.exit()
    status=osc(server_ip,server_port,dbname,tabname,ddlstmt)
    print status