【发布时间】：2016-11-15 00:41:02
【问题描述】：
我在两台不同的服务器上有一个主到主复制设置，它们在 Red Hat Linux 上托管 MySQL Ver 14.14、Distrib 5.1.16。当我重新启动其中一台服务器时，从服务器没有启动。当我执行 /var/lib/mysql 目录的列表时，我注意到 master.info 文件被截断为零长度，这导致 MySQL 认为没有设置复制。
这是服务器 1 的 my.cnf：
[client]
port = 3306
socket = /var/lib/mysql/mysql.sock
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
key_buffer = 16M
max_allowed_packet = 1M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
myisam_sort_buffer_size = 8M
log-bin = mysql-bin
relay-log = mysqld-relay-bin
relay-log-index = mysqld-relay-bin.index
server-id = 101
binlog-format = STATEMENT
replicate-do-db = foo
replicate-do-db = bar
binlog-do-db = foo
binlog-do-db = bar
auto_increment_increment = 2
auto_increment_offset = 1
master-connect-retry = 2
sync_binlog = 1
log-error = mysqld.log
log-warnings = 2
wait_timeout = 31536000
expire_logs_days = 45
这里是服务器 2 的 my.cnf：
[client]
port = 3306
socket = /var/lib/mysql/mysql.sock
[mysqldump]
quick
max_allowed_packet = 16M
[mysql]
no-auto-rehash
[isamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[myisamchk]
key_buffer = 20M
sort_buffer_size = 20M
read_buffer = 2M
write_buffer = 2M
[mysqlhotcopy]
interactive-timeout
[mysqld]
port = 3306
socket = /var/lib/mysql/mysql.sock
key_buffer = 16M
max_allowed_packet = 1M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
myisam_sort_buffer_size = 8M
log-bin = mysql-bin
relay-log = mysqld-relay-bin
relay-log-index = mysqld-relay-bin.index
server-id = 102
binlog-format = STATEMENT
replicate-do-db = foo
replicate-do-db = bar
binlog-do-db = foo
binlog-do-db = bar
auto_increment_increment = 2
auto_increment_offset = 2
master-connect-retry = 2
sync_binlog = 1
log-error = mysqld.log
log-warnings = 2
wait_timeout = 31536000
expire_logs_days = 45
我像这样在每台服务器上设置从站：
STOP SLAVE ; RESET SLAVE ; CHANGE MASTER TO MASTER_HOST='other_sys', MASTER_USER='repl', MASTER_PASSWORD='super_secret_password', MASTER_PORT=3306, MASTER_LOG_FILE='mysql-bin.000001', MASTER_LOG_POS=14048 ;
在上面的例子中，MASTER_LOG_FILE 和 MASTER_LOG_POS 只是任意的。完成此操作后，我得到以下 MySQL 从站状态：
mysql> show slave status \G
*************************** 1. row ***************************
Slave_IO_State: Waiting for master to send event
Master_Host: other_sys
Master_User: repl
Master_Port: 3306
Connect_Retry: 2
Master_Log_File: mysql-bin.000002
Read_Master_Log_Pos: 14048
Relay_Log_File: mysqld-relay-bin.000002
Relay_Log_Pos: 251
Relay_Master_Log_File: mysql-bin.000002
Slave_IO_Running: Yes
Slave_SQL_Running: Yes
Replicate_Do_DB: foo,bar
Replicate_Ignore_DB:
Replicate_Do_Table:
Replicate_Ignore_Table:
Replicate_Wild_Do_Table:
Replicate_Wild_Ignore_Table:
Last_Errno: 0
Last_Error:
Skip_Counter: 0
Exec_Master_Log_Pos: 14048
Relay_Log_Space: 407
Until_Condition: None
Until_Log_File:
Until_Log_Pos: 0
Master_SSL_Allowed: No
Master_SSL_CA_File:
Master_SSL_CA_Path:
Master_SSL_Cert:
Master_SSL_Cipher:
Master_SSL_Key:
Seconds_Behind_Master: 0
Master_SSL_Verify_Server_Cert: No
Last_IO_Errno: 0
Last_IO_Error:
Last_SQL_Errno: 0
Last_SQL_Error:
1 row in set (0.00 sec)
然后我使用命令reboot 重新启动服务器。重新启动后，MySQL 从站有时会从它停止的地方自动启动。其他时候，MySQL 从站根本不会启动，我注意到show slave status \G 返回一个空集，并且 /var/lib/mysql/master.info 文件被截断为零长度。就好像 Linux 在重新启动时没有将文件缓冲区刷新到 inode 一样，因此从站信息不会被保存。
在配置从站时我是否遗漏了什么？
【问题讨论】：
标签： mysql linux configuration