def change_to_new_master():
global middle_master_file
global middle_master_pos
global error_code
try:
# ######################切换
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
# ###游标
cursor_slave = slave.cursor()
# 在从库上reset slave
print('在从库上reset slave')
# 因为start slave until到达指定位置后只会停止SQL_THREAD,而reset slave需要全部停止，所以需要再次全部停止
cursor_slave.execute('stop slave')
cursor_slave.execute('reset slave all')
print('now begin change')
change_sql = '''change master to MASTER_HOST='{}',MASTER_PORT={},MASTER_USER='******',MASTER_PASSWORD='******',MASTER_LOG_FILE='{}',MASTER_LOG_POS={}''' \
.format(new_master_host, new_master_port, opreate_user, opreate_password, middle_master_file, int(middle_master_pos))
print(change_sql)
print('开始切换到新主库')
cursor_slave.execute(change_sql)
cursor_slave.execute('start slave')
print_slave_status(slave)
except Exception:
error_code = 'change_to_new_master'
raise Exception
def stop_the_middle():
print(
'# #################################连接到中间库上停止IO进程获取其pos,file,start###############################'
)
try:
global middle_master_file
global middle_master_pos
global orgin_file
global origin_pos
global error_code
middle_master = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
# ###游标
cursor_middle_master = middle_master.cursor()
# ##停止IO进程，等待SQL线程完成复制
cursor_middle_master.execute('stop slave io_thread')
# ##检查SQL线程是否完成复制
while 1:
print('checking replication process')
time.sleep(5) # 循环检查的间隔5s
(a, b, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
if slave_io_file == slave_sql_file and slave_io_pos == slave_sql_pos:
print('sql thread finished replicate')
break
(orgin_file, origin_pos) = (slave_io_file, slave_io_pos)
(middle_master_file,
middle_master_pos) = print_selfbinlog_status(middle_master)
cursor_middle_master.execute('start slave')
except Exception:
error_code = 'stop_the_middle'
raise Exception
def stop_at_chose_pos():
global orgin_file
global origin_pos
global error_code
# ########################停在同一个位置
try:
print('停止SQL线程')
start_until_sql = '''start slave until MASTER_LOG_FILE = '{}', MASTER_LOG_POS = {}''' \
.format(orgin_file, int(origin_pos))
print(start_until_sql)
print('开始停止到中间库的指定位置')
# #被切换的从库
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
# ###游标
cursor_slave = slave.cursor()
cursor_slave.execute(start_until_sql)
# ###检查是否到达指定位置
while 1:
print('checking replication process')
time.sleep(5) # 循环检查的间隔5s
(a, b, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
if slave_io_file == slave_sql_file and slave_io_pos == slave_sql_pos:
print('sql thread finished replicate')
break
except Exception:
error_code = 'stop_at_same_pos'
raise Exception
def pre_check():
global error_code
# ##################先预检，判断当前复制拓补是否为一主两从，两个从库是否存在slave线程（SQL,IO任一）停止的情况###########
(master_host_N, master_port_N, new_master_io_file, new_master_io_pos,
new_master_sql_file, new_master_sql_pos) = print_slave_status(new_master)
(master_host_S, master_port_S, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
(io_thread_running_n, sql_thread_running_n) = print_rep_info(new_master)
(io_thread_running_s, sql_thread_running_s) = print_rep_info(slave)
print('########################预检模块开始###########################')
if master_host_N == master_host_S and master_port_N == master_port_S \
and io_thread_running_n == 'Yes' and io_thread_running_n == 'Yes' \
and io_thread_running_s == 'Yes' and io_thread_running_s == 'Yes':
print('复制链路正确，slave线程全部running')
print('master_port_N:', master_port_N, 'master_port_S:', master_port_S)
else:
error_code = 'pre_check'
raise Exception
def after_change():
global error_code
try:
time.sleep(3)
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
# ###游标
cursor_slave = slave.cursor()
(master_host_S, master_port_S, a, b, c, d) = print_slave_status(slave)
(io_thread_running_s, sql_thread_running_s) = print_rep_info(slave)
if master_port_S == new_master_host and master_port_S == new_master_port \
and io_thread_running_s == 'Yes' and io_thread_running_s == 'Yes':
print('change OK,slave running!!!')
except Exception:
error_code = 'after_change'
raise Exception
def stop_slave_io_thread():
# #################################连接到从库上停止IO进程###############################
try:
global error_code
print(
'# #################################连接到从库上停止IO进程###############################'
)
# #被切换的从库
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
# ###游标
cursor_slave = slave.cursor()
# ##停止SLAVE IO进程,但不停止SQL进程，防止SQL线程落后于IO进程
cursor_slave.execute('stop slave io_thread')
time.sleep(3) # 等待3秒，让中间库的IO进度快于自己的IO
# ###输出执行后的slave进程状态
(a, b, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
except Exception:
error_code = 'stop_slave_io_thread'
raise Exception
new_master = pymysql.Connect(host=new_master_host,
port=new_master_port,
user=opreate_user,
passwd=opreate_password)
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
master = pymysql.Connect(host=master_host,
port=master_port,
user=opreate_user,
passwd=opreate_password)
(master_host_N, master_port_N, new_master_io_file, new_master_io_pos,
new_master_sql_file, new_master_sql_pos) = print_slave_status(new_master)
(master_host_S, master_port_S, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
(io_thread_running_n, sql_thread_running_n) = print_rep_info(new_master)
(io_thread_running_s, sql_thread_running_s) = print_rep_info(slave)
# 预检模块
def pre_check():
global error_code
# ##################先预检，判断当前复制拓补是否为一主两从，两个从库是否存在slave线程（SQL,IO任一）停止的情况###########
(master_host_N, master_port_N, new_master_io_file, new_master_io_pos,
new_master_sql_file, new_master_sql_pos) = print_slave_status(new_master)
(master_host_S, master_port_S, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
middle_master = pymysql.Connect(host=middle_master_host,
port=middle_master_port,
user=opreate_user,
passwd=opreate_password)
slave = pymysql.Connect(host=slave_host,
port=slave_port,
user=opreate_user,
passwd=opreate_password)
master = pymysql.Connect(host=master_host,
port=master_port,
user=opreate_user,
passwd=opreate_password)
(master_host_N, master_port_N, middle_master_io_file, middle_master_io_pos,
middle_master_sql_file,
middle_master_sql_pos) = print_slave_status(middle_master)
(master_host_S, master_port_S, slave_io_file, slave_io_pos, slave_sql_file,
slave_sql_pos) = print_slave_status(slave)
(io_thread_running_n, sql_thread_running_n) = print_rep_info(middle_master)
(io_thread_running_s, sql_thread_running_s) = print_rep_info(slave)
# 预检模块
def pre_check():
global error_code
# ##################先预检，判断当前复制拓补是否为一主两从，两个从库是否存在slave线程（SQL,IO任一）停止的情况###########
(master_host_N, master_port_N, middle_master_io_file, middle_master_io_pos,
middle_master_sql_file,
middle_master_sql_pos) = print_slave_status(middle_master)
(master_host_S, master_port_S, slave_io_file, slave_io_pos, slave_sql_file,
