root@mysqltest:/etc/mysql/mysql.conf.d# cat mysqld.cnf## The MySQL database server configuration file.## You can copy this to one of:# - "/etc/mysql/my.cnf" to set global options,# - "~/.my.cnf" to set user-specific options.# # One can use all long options that the program supports.# Run program with --help to get a list of available options and with# --print-defaults to see which it would actually understand and use.## For explanations see# http://dev.mysql.com/doc/mysql/en/server-system-variables.html# This will be passed to all mysql clients# It has been reported that passwords should be enclosed with ticks/quotes# escpecially if they contain "#" chars...# Remember to edit /etc/mysql/debian.cnf when changing the socket location.# Here is entries for some specific programs# The following values assume you have at least 32M ram[mysqld_safe]socket		= /var/run/mysqld/mysqld.socknice		= 0[mysqld]## * Basic Settings#user		= mysqlpid-file	= /var/run/mysqld/mysqld.pidsocket		= /var/run/mysqld/mysqld.sockport		= 3306basedir		= /usrdatadir		= /var/lib/mysqltmpdir		= /tmplc-messages-dir	= /usr/share/mysqlinteractive_timeout = 9504000wait_timeout        = 9504000skip-external-locking## Instead of skip-networking the default is now to listen only on# localhost which is more compatible and is not less secure.# bind-address		= 127.0.0.1## * Fine Tuning#key_buffer_size		= 16Mmax_allowed_packet	= 16Mthread_stack		= 192Kthread_cache_size       = 8lower_case_table_names=1# This replaces the startup script and checks MyISAM tables if needed# the first time they are touchedmyisam-recover-options  = BACKUP#max_connections        = 100#table_cache            = 64#thread_concurrency     = 10## * Query Cache Configuration#query_cache_limit	= 1Mquery_cache_size        = 16M## * Logging and Replication## Both location gets rotated by the cronjob.# Be aware that this log type is a performance killer.# As of 5.1 you can enable the log at runtime!#general_log_file        = /var/log/mysql/mysql.log#general_log             = 1## Error log - should be very few entries.#log_error = /var/log/mysql/error.log## Here you can see queries with especially long duration#log_slow_queries	= /var/log/mysql/mysql-slow.log#long_query_time = 2#log-queries-not-using-indexes## The following can be used as easy to replay backup logs or for replication.# note: if you are setting up a replication slave, see README.Debian about#       other settings you may need to change.#server-id		= 1#log_bin			= /var/log/mysql/mysql-bin.logexpire_logs_days	= 10max_binlog_size   = 100M#binlog_do_db		= include_database_name#binlog_ignore_db	= include_database_name## * InnoDB## InnoDB is enabled by default with a 10MB datafile in /var/lib/mysql/.# Read the manual for more InnoDB related options. There are many!## * Security Features## Read the manual, too, if you want chroot!# chroot = /var/lib/mysql/## For generating SSL certificates I recommend the OpenSSL GUI "tinyca".## ssl-ca=/etc/mysql/cacert.pem# ssl-cert=/etc/mysql/server-cert.pem# ssl-key=/etc/mysql/server-key.pemroot@mysqltest:/etc/mysql/mysql.conf.d#

需要特别注意的是：

interactive_timeout = 9504000wait_timeout        = 9504000skip-external-locking## Instead of skip-networking the default is now to listen only on# localhost which is more compatible and is not less secure.# bind-address		= 127.0.0.1## * Fine Tuning#key_buffer_size		= 16Mmax_allowed_packet	= 16Mthread_stack		= 192Kthread_cache_size       = 8lower_case_table_names=1# This replaces the startup script and checks MyISAM tables if needed# the first time they are touchedmyisam-recover-options  = BACKUP#max_connections        = 100#table_cache            = 64#thread_concurrency     = 10## * Query Cache Configuration#query_cache_limit	= 1Mquery_cache_size        = 16M

    如果需要远程访问，需要注释掉

# bind-address		= 127.0.0.1 Ubuntu16.0.4中MySQL的配置文件存在于/etc/mysql/mysql.conf.d/mysqld.cnf

root@mysqltest:/etc/mysql/mysql.conf.d# pwd

/etc/mysql/mysql.conf.d

root@mysqltest:/etc/mysql/mysql.conf.d# ll

total 16

drwxr-xr-x 2 root root 4096 Oct 24 10:51 ./

drwxr-xr-x 4 root root 4096 Sep 22 15:40 ../

-rw-r--r-- 1 root root 3115 Oct 24 10:51 mysqld.cnf

-rw-r--r-- 1 root root 21 Feb 4 2017 mysqld_safe_syslog.cnf

另外java项目配置hibernate的时候加上自动重连的参数

hibernate.connection.url=jdbc:mysql://ip:3306/ucom?characterEncoding=utf8&autoReconnect=true

如果是xml，&符号需要&进行转义

<Resource auth="Container" driverClassName="com.mysql.jdbc.Driver" maxActive="80" maxIdle="30" maxWait="1000" name="ucomdb" password="gdyl2017" type="javax.sql.DataSource" url="jdbc:mysql://ip:3306/ucom?characterEncoding=utf8&amp;autoReconnect=true" username="root"/>