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MySQL“服务器已经消失”使用SQLyog

2019-08-06 22:17:47 作者：互联网

我正在尝试将数据库从服务器复制到我的本地机器,我已经安装了Wamp 2.2,mysql 5.5.16,但在复制数据库时我得到“mysql服务器已经消失”2006,我试图修复它通过将max_allowed_packet更改为32M和64M但仍然没有运气,我也改变了等待时间.

wait_timeout=28800
interactive_timeout = 28800

我在my.ini中的配置

# Example MySQL config file for medium systems.
#
# This is for a system with little memory (32M - 64M) where MySQL plays
# an important part, or systems up to 128M where MySQL is used together with
# other programs (such as a web server)
#
# You can copy this file to
# /etc/my.cnf to set global options,
# mysql-data-dir/my.cnf to set server-specific options (in this
# installation this directory is C:\mysql\data) or
# ~/.my.cnf to set user-specific options.
#
# In this file, you can use all long options that a program supports.
# If you want to know which options a program supports, run the program
# with the "--help" option.

# The following options will be passed to all MySQL clients
[client]
#password   = your_password
port        = 3306
socket      = /tmp/mysql.sock

# Here follows entries for some specific programs

# The MySQL server
[wampmysqld]
port        = 3306
socket      = /tmp/mysql.sock
key_buffer = 16M
max_allowed_packet = 64M
table_cache = 64
sort_buffer_size = 512K
net_buffer_length = 8K
read_buffer_size = 256K
read_rnd_buffer_size = 512K
myisam_sort_buffer_size = 8M
basedir=c:/wamp/bin/mysql/mysql5.5.16
log-error=c:/wamp/logs/mysql.log
datadir=c:/wamp/bin/mysql/mysql5.5.16/data

# Don't listen on a TCP/IP port at all. This can be a security enhancement,
# if all processes that need to connect to mysqld run on the same host.
# All interaction with mysqld must be made via Unix sockets or named pipes.
# Note that using this option without enabling named pipes on Windows
# (via the "enable-named-pipe" option) will render mysqld useless!
# 
#skip-networking

# Disable Federated by default
skip-federated

# Replication Master Server (default)
# binary logging is required for replication
log-bin=mysql-bin

# binary logging format - mixed recommended
binlog_format=mixed

# required unique id between 1 and 2^32 - 1
# defaults to 1 if master-host is not set
# but will not function as a master if omitted
server-id   = 1

# Replication Slave (comment out master section to use this)
#
# To configure this host as a replication slave, you can choose between
# two methods :
#
# 1) Use the CHANGE MASTER TO command (fully described in our manual) -
#    the syntax is:
#
#    CHANGE MASTER TO MASTER_HOST=<host>, MASTER_PORT=<port>,
#    MASTER_USER=<user>, MASTER_PASSWORD=<password> ;
#
#    where you replace <host>, <user>, <password> by quoted strings and
#    <port> by the master's port number (3306 by default).
#
#    Example:
#
#    CHANGE MASTER TO MASTER_HOST='125.564.12.1', MASTER_PORT=3306,
#    MASTER_USER='joe', MASTER_PASSWORD='secret';
#
# OR
#
# 2) Set the variables below. However, in case you choose this method, then
#    start replication for the first time (even unsuccessfully, for example
#    if you mistyped the password in master-password and the slave fails to
#    connect), the slave will create a master.info file, and any later
#    change in this file to the variables' values below will be ignored and
#    overridden by the content of the master.info file, unless you shutdown
#    the slave server, delete master.info and restart the slaver server.
#    For that reason, you may want to leave the lines below untouched
#    (commented) and instead use CHANGE MASTER TO (see above)
#
# required unique id between 2 and 2^32 - 1
# (and different from the master)
# defaults to 2 if master-host is set
# but will not function as a slave if omitted
#server-id       = 2
#
# The replication master for this slave - required
#master-host     =   <hostname>
#
# The username the slave will use for authentication when connecting
# to the master - required
#master-user     =   <username>
#
# The password the slave will authenticate with when connecting to
# the master - required
#master-password =   <password>
#
# The port the master is listening on.
# optional - defaults to 3306
#master-port     =  <port>
#
# binary logging - not required for slaves, but recommended
#log-bin=mysql-bin

# Point the following paths to different dedicated disks
#tmpdir     = /tmp/     
#log-update     = /path-to-dedicated-directory/hostname

# Uncomment the following if you are using InnoDB tables
#innodb_data_home_dir = C:\mysql\data/
#innodb_data_file_path = ibdata1:10M:autoextend
#innodb_log_group_home_dir = C:\mysql\data/
#innodb_log_arch_dir = C:\mysql\data/
# You can set .._buffer_pool_size up to 50 - 80 %
# of RAM but beware of setting memory usage too high
#innodb_buffer_pool_size = 16M
#innodb_additional_mem_pool_size = 2M
# Set .._log_file_size to 25 % of buffer pool size
#innodb_log_file_size = 5M
#innodb_log_buffer_size = 8M
#innodb_flush_log_at_trx_commit = 1
#innodb_lock_wait_timeout = 50

[mysqldump]
quick
max_allowed_packet = 64M

[mysql]
no-auto-rehash
# Remove the next comment character if you are not familiar with SQL
#safe-updates

[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]
wait_timeout=28800
interactive_timeout = 28800

[mysqld]
wait_timeout=28800
interactive_timeout = 28800
port=3306

有人能告诉我我错过了什么吗？

解决方法:

以下是repost of an answer I posted with similar circumstances back on Sep 1, 2011

MySQL Connections的一个无声杀手是MySQL数据包.事实上,即使是MySQL复制的I / O线程也可能成为这一点的牺牲品.

根据MySQL Documentation

>如果向服务器发送不正确或太大的查询,也可能会出现这些错误.如果mysqld收到的数据包太大或无序,则会假定客户端出现问题并关闭连接.如果需要大查询(例如,如果使用大型BLOB列),则可以通过设置服务器的max_allowed_packet变量来增加查询限制,该变量的默认值为1MB.您可能还需要增加客户端的最大数据包大小.有关设置数据包大小的更多信息,请参见Section C.5.2.10, “Packet too large”.
>插入大量行的任何INSERT或REPLACE语句也可能导致这些类型的错误.这些语句中的任何一个都向服务器发送单个请求,而不管要插入的行数是多少;因此,您通常可以通过减少每个INSERT或REPLACE发送的行数来避免错误.

至少,您必须确保mysqldump来自的机器和您加载的机器的数据包大小相同.

您可以采取两种方法：

方法#1：使用–skip-extended-insert执行mysqldump

这将确保MySQL数据包不会被多个BLOB,TEXT字段所淹没.这样,SQL INSERT一次执行一个.主要缺点是

> mysqldump要大得多
>重新加载这样的转储需要更长的时间.

方法#2：增加max_allowed_packet

这可能是首选方法,因为实现它只是重新启动mysql.了解MySQL数据包可能会澄清这一点.

根据page 99 of “Understanding MySQL Internals” (ISBN 0-596-00957-7),以下是第1-3段解释它：

MySQL network communication code was
written under the assumption that
queries are always reasonably short,
and therefore can be sent to and
processed by the server in one chunk,
which is called a packet in MySQL
terminology. The server allocates the
memory for a temporary buffer to store
the packet, and it requests enough to
fit it entirely. This architecture
requires a precaution to avoid having
the server run out of memory—a cap
on the size of the packet, which this
option accomplishes.

The code of interest in relation to
this option is found in
sql/net_serv.cc. Take a look at my_net_read(), then follow the call to my_real_read() and pay
particular attention to
net_realloc().

This variable also limits the length
of a result of many string functons.
See sql/field.cc and
sql/intem_strfunc.cc for details.

鉴于此解释,批量INSERT将很快加载/卸载MySQL数据包.当max_allowed_packet对于来自它的给定数据负载来说太小时尤其如此.

结论

在MySQL的大多数安装中,我通常将其设置为256M或512M.当数据加载产生“MySQL已经消失”错误时,您应该体验更大的值.

标签：mysql,my-cnf
来源： https://codeday.me/bug/20190806/1603784.html