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install redhat rh-mariadb103

paulwong — Sat, 24 Oct 2020 10:02:00 GMT

# Install MariaDB 10.3
yum install rh-mariadb103-mariadb-server rh-mariadb103-mariadb-server-utils -y

# Add MariaDB 10.3 to $PATH
scl enable rh-mariadb103 bash
source /opt/rh/rh-mariadb103/enable

# start 10.3 server
chown -R mysql:mysql /var/opt/rh/rh-mariadb103/lib/mysql;
systemctl start rh-mariadb103-mariadb

# Upgrade tables
mysql_upgrade -p[PASSWORD]

# Set 10.3 to start on boot
systemctl enable rh-mariadb103-mariadb

# Add 10.3 to paths on reboot (and remove 10.2)
rm /etc/profile.d/rh-mariadb102.sh
cp /opt/rh/rh-mariadb103/enable /etc/profile.d/rh-mariadb103.sh

# increase max connections number
systemctl edit rh-mariadb103-mariadb
[Service]
LimitNOFILE=65535
LimitNPROC=65535

vi /etc/opt/rh/rh-mariadb103/my.cnf
[mysqld]
max_connections=1000
open_files_limit=65535

# restart mariadb103
systemctl daemon-reload
systemctl restart rh-mariadb103-mariadb

# check result
mysql -e 'show variables like "max_connections"'

https://www.server-world.info/en/note?os=CentOS_7&p=mariadb103&f=4

paulwong 2020-10-24 18:02 发表评论

MYSQL�l�典配置

paulwong — Fri, 07 Aug 2020 10:01:00 GMT

/etc/my.cnf

[mysqld]
datadir=/var/lib/mysql
socket=/var/lib/mysql/mysql.sock
#symbolic-links=0

#vish start
open_files_limit = 8000
max_connections = 500
#set-variable=max_connections=500
thread_concurrency = 8
#concurrent_insert=2
thread_cache_size=2000

interactive_timeout=180
wait_timeout=180

max_allowed_packet = 32M
key_buffer_size = 3000M
read_buffer_size = 16M
read_rnd_buffer_size = 4M
bulk_insert_buffer_size = 256M
myisam_sort_buffer_size = 16M
myisam_max_sort_file_size = 256M
myisam_repair_threads = 1
#myisam_recover = 4
max_heap_table_size = 2048M
tmp_table_size = 1024M
table_open_cache = 2000
table_cache = 2000
sort_buffer_size = 128M
join_buffer_size = 128M
query_cache_size = 128M
query_cache_limit = 128M

#slow_query_log=1
log-slow-queries
long_query_time=2
#log_queries_not_using_indexes=1
slow_query_log_file = /var/log/mariadb/host_name-slow.log

[mysqldump]
user=root
password=*********
#max_allowed_packet = 1024M

[myisamchk]
key_buffer_size = 2500M
sort_buffer_size = 1024M
read_buffer = 32M
write_buffer = 32M

[innodb]
innodb_buffer_pool_size=3G
innodb_buffer_pool_instance=2
innodb_additional_mem_pool_size=20M
innodb_log_file_size= 512M
innodb_log_buffer_size=16M
innodb_flush_log_at_trx_commit=1
innodb_thread_concurrency=16
#innodb_read_io_threads=16
#innodb_write_io_threads=16
#innodb_io_capacity=2000
#innodb_lock_wait_timeout=120

innodb_flush_method=O_DIRECT
#vish end

[mysqld_safe]
log-error=/var/log/mariadb/mariadb.log
pid-file=/var/run/mariadb/mariadb.pid
#!includedir /etc/my.cnf.d

paulwong 2020-08-07 18:01 发表评论

paulwong — Wed, 05 Aug 2020 12:55:00 GMT

MARIADB的默认最大连接数�?00�Q�当试图更改配置文�g/etc/my.conf�q�加max_connections=1000�Q��ƈ重启服务�Ӟ��发现最大连接数被重�|��ؓ214�Q�这是由于系�l�问题，open_files��Cؓ1024�Q�如何正��地更改是个复杂的问题�?br />
MARIADB中一些查当前�q�接�?最大连接数的命令�ؓ�Q?br />

MariaDB [(none)]>
show variables like "max_connections";
show processlist;
show status where variable_name = 'threads_connected';
show status where variable_name = 'max_used_connections';
show variables like 'max_user_connections';
show variables like '%connection%';

正确�Ҏ��Q?br /> RHEL\CentOS 7 �?MySQL �q�接数被限制�?14�?br /> https://waylau.com/rhel-mysql-connections-limit-214/

Centos7.4下面mysql的max_connections不生效的问题�?br /> https://blog.51cto.com/wangqh/2131340

��Z��要在SERVICE中添加允许打开的文件数�Q?br /> Centos7下修�?etc/security/limits.conf文�g只在用户��d��后打开的进�E�有效，�pȝ��服务或通过rc.local启动的无效，�pȝ��服务修改文�g/usr/lib/systemd/system/SOME_SERVICE.service��d��Q?br />

[Service]
LimitNOFILE=65535

关于LINUX�pȝ��的最大打开文�g敎ͼ�
https://blog.51cto.com/as007012/1956222

https://www.haiyun.me/archives/linux-file-limit.html

paulwong 2020-08-05 20:55 发表评论

MariaDB Galera Cluster

paulwong — Sat, 09 May 2020 03:08:00 GMT

What is MariaDB Galera Cluster?

https://mariadb.com/kb/en/what-is-mariadb-galera-cluster/

Prepare yum install repository:
https://downloads.mariadb.org/mariadb/repositories/#distro=CentOS&distro_release=centos7-amd64--centos7&mirror=coreix&version=10.4

MariaDB Galera Cluster部��v实战
https://jeremyxu2010.github.io/2018/02/mariadb-galera-cluster%E9%83%A8%E7%BD%B2%E5%AE%9E%E6%88%98/

9 Tips for Going in Production with Galera Cluster for MySQL

https://severalnines.com/blog/9-tips-going-production-galera-cluster-mysql

HA for MySQL and MariaDB - Comparing Master-Master Replication to Galera Cluster

https://severalnines.com/database-blog/ha-mysql-and-mariadb-comparing-master-master-replication-galera-cluster

Galera Cluster for MySQL - Tutorial

https://severalnines.com/resources/tutorials/galera-cluster-mysql-tutorial

paulwong 2020-05-09 11:08 发表评论

List sessions / active connections on MariaDB server

paulwong — Thu, 02 Apr 2020 07:38:00 GMT

Using a command

Option 1

show status where variable_name = 'threads_connected';

Columns

Variable_name - Name of the variable shown
Value - Number of active connections

Rows

One row: Only one row is displayed

Sample results

Option 2

show processlist;

Columns

Id - The connection identifier
User - The MariaDB user who issued the statement
Host - Host name and client port of the client issuing the statement
db - The default database (schema), if one is selected, otherwise NULL
Command - The type of command the thread is executing
Time - The time in seconds that the thread has been in its current state
State - An action, event, or state that indicates what the thread is doing
Info - The statement the thread is executing, or NULL if it is not executing any statement
Progress - The total progress of the process (0-100%)

Rows

One row: represents one active connection
Scope of rows: total of active connections

Sample results

Using a query

Option 3

select id, user, host, db, command, time, state, 
info, progress from information_schema.processlist;

Columns

Id - The connection identifier
User - The MariaDB user who issued the statement
Host - Host name and client port of the client issuing the statement
db - The default database (schema), if one is selected, otherwise NULL
Command - The type of command the thread is executing
Time - The time in seconds that the thread has been in its current state
State - An action, event, or state that indicates what the thread is doing
Info - The statement the thread is executing, or NULL if it is not executing any statement
Progress - The total progress of the process (0-100%)
memory_used - Amount of memory used by the active connection

Rows

One row: represents one active connection
Scope of rows: total of active connections

Sample results

Using the GUI

Option 4

Click on the Client Connections option of the Management tab (left navigation pane)

This action will show the Client Connections screen containing the current active connections

paulwong 2020-04-02 15:38 发表评论

利用 Chef �?Red Hat Enterprise Linux 上自动化部��v Mariadb Galera Cluster

paulwong — Sat, 21 Mar 2020 02:55:00 GMT

https://www.ibm.com/developerworks/cn/linux/1611_chensz_mgc/index.html

paulwong 2020-03-21 10:55 发表评论

mySQL Error 1040: Too Many Connection

paulwong — Tue, 10 Mar 2020 12:20:00 GMT

To see how many connections are configured for your DB to use:

select @@max_connections;

To change it:

set global max_connections = 200;

To see how many are connected at the current time:

show processlist;

vi /etc/my.cnf

[mysqld]
max_connections = 500

paulwong 2020-03-10 20:20 发表评论

centos7 mysql数据库安装和配置

paulwong — Fri, 14 Jun 2019 02:24:00 GMT

https://www.cnblogs.com/starof/p/4680083.html

https://www.daniloaz.com/en/how-to-create-a-user-in-mysql-mariadb-and-grant-permissions-on-a-specific-database/

https://huongdanjava.com/mysql-2

http://www.runoob.com/mysql/mysql-install.html

paulwong 2019-06-14 10:24 发表评论

MYSQL HA资源

paulwong — Sun, 23 Mar 2014 14:51:00 GMT

http://stackoverflow.com/questions/22495722/mysql-master-slave-replication-connect-to-master-even-for-read-queries-does-d

http://www.dragishak.com/?p=307

http://blog.csdn.net/lixiucheng005/article/details/17391857

http://blog.csdn.net/cutesource/article/details/5710645

paulwong 2014-03-23 22:51 发表评论

数据库的防单�Ҏ��障和分表分库

paulwong — Sun, 23 Mar 2014 13:27:00 GMT

通常数据库是安装在一台服务器上，如果服务器DOWN机，则数据服务停止。这样在生��环境是不合适的�Q�必��部�|�两��C��上的服务器且都安装有相同数据的数据库。这样就产生了一个问题，同一份数据在不同的机子上�Q�会��D��数据不同步的问题。一般的�Ҏ��是：

服务端：

互责数据同步�Q�一台服务器专门做写操作�Q�其他服务器只做��L��作，即主从模式。当��L��务器DOWN机时�Q�会在从服务器中选出一台做��L��务器。在MONGODB中叫REPLICATION�?/div>

客户端：

要判断当前与数据库的链接�Q�如果是��L��作，则��用与从服务器的链接，如果是写操作�Q�则使用与主服务器的链接。这��L��判断一般是由驱动程序去做，配置的时候如果是MYSQL�Q�就要��用REPLYCATION的驱动�?/div>

如果数据库里的某张表数据太多�Q�会��D��单的查询会需时过长的问题。一般的�Ҏ��是限制每张表中不能放太多的数据，如第一个月的数据放一张表�Q�下一个月的数据放�W�二张表�Q�这�U�做法称为SHARDING�Q�分表。但�q�样会导致查询的复杂性，如数据在�W�二张表�Q�则要具体指明表名，否则查不出数据。目前的数据库，可以事先指定分表的规则，�q�样查询的语句不需改变�Q�数据库端会自动判断数据在哪张表�Q�然后�\由到那张表，��L��找数据然后返回给客户端。ORACLE叫分��Q�MONGODB叫AUTO SHARDING�?/div>

服务端：

需事先指定数据分表规则�Q�这��h��到查询语句时数据库就知道数据在哪张表中�?/div>

客户端：

查询数据时无需再指定分��名了

paulwong 2014-03-23 21:27 发表评论

一些数据切分、缓存、rpc框架、nosql�Ҏ��资料

paulwong — Mon, 14 Oct 2013 02:14:00 GMT

1、数据切�?/span>

1.1�?a style="color: #108ac6;" target="_blank">mysql中间件研�IӞ��Atlas�Q�cobar�Q�TDDL�Q?/a>

1.2�?a style="color: #108ac6;" target="_blank">利用 MySQL Proxy 实现数据切分及整�?nbsp;

1.3�?a style="color: #108ac6;" target="_blank">��Z��MySQL分库分表�Ҏ��?nbsp;

1.4�?a style="color: #108ac6;" target="_blank">tddl和diamond

2、缓�?/p>

2.1�?a style="color: #108ac6;" target="_blank">java客户端三�U�方式操�?nbsp;

2.2�?a style="color: #108ac6;" target="_blank">myibatis配置memcached评测

2.3�?a style="color: #108ac6;" target="_blank">Memcached + Spring Caching

2.4�?a style="color: #108ac6;" target="_blank">memcachedb-持久化存储的�~�存�pȝ��

2.5�?a style="color: #108ac6;" target="_blank">memcachedb让memcache的数据持久化

2.6�?a style="color: #108ac6;" target="_blank">淘宝kv�~�存框架tair

2.7�?a style="color: #108ac6;" target="_blank">ibatis之扩展缓存ibatis-tair-cache

3、rpc框架

3.1�?a style="color: #108ac6;">dubbo

3.2、hsf 未开�?/p>

3.3�?a style="color: #108ac6;" target="_blank">服务框架HSF分析之一容器启动

4、noSql

4.1�?a style="color: #108ac6;" target="_blank">学习NoSQL数据库的必读资料

paulwong 2013-10-14 10:14 发表评论

Ubuntu下彻底卸载mysql

paulwong — Sun, 21 Jul 2013 13:24:00 GMT

1、删�?mysql

1 sudo apt-get autoremove --purge mysql-server-5.0
2 sudo apt-get remove mysql-server
3 sudo apt-get autoremove mysql-server
4 sudo apt-get remove mysql-common (非常重要)

上面的其实有一些是多余的，��q�是按照��序执行一�?br />
清理�D�留数据

dpkg -l |grep ^rc|awk '{print $2}' |sudo xargs dpkg -P

2、安�?mysql

1 sudo apt-get install mysql-server
2 sudo apt-get install mysql-client
3 sudo apt-get install php5-mysql(安装php5-mysql 是将php和mysql�q�接��h�� )

一旦安装完成，MySQL 服务器应该自动启动。您可以在终端提�C�符后运行以下命令来��?MySQL 服务器是否正在运行：

1 sudo netstat -tap | grep mysql

当您�q�行该命令时�Q�您可以看到�c�M��下面的行�Q?br />

tcp 0 0 localhost.localdomain:mysql *:* LISTEN -

如果服务器不能正常运行，您可以通过下列命��o启动它：

1 sudo /etc/init.d/mysql restart

3、进入mysql

$mysql -uroot -p ��理员密�?/div> 配置 MySQL 的管理员密码�Q?br />

1 sudo mysqladmin -u root password newpassword

4、恢复数据库

mysql -p < html5canvas-20130930-0816.sql

http://www.yesky.com/187/1754687.shtml

TOMCAT数据�?br />http://136589219.iteye.com/blog/1572214

paulwong 2013-07-21 21:24 发表评论

paulwong — Tue, 07 May 2013 01:19:00 GMT

一�Q�什么是mysql分表�Q�分�?/strong>

什么是分表�Q�从表面意思上看呢�Q�就是把一张表分成N多个��表�Q�具体请�?strong style="padding: 0px; margin: 0px;">mysql分表�?�U�方�?/a>

什么是分区�Q�分区呢��是把一张表的数据分成N多个区块�Q�这些区块可以在同一个磁盘上�Q�也可以在不同的��盘上，具体请参�?strong style="padding: 0px; margin: 0px;">mysql分区功能详细介绍�Q�以及实�?/a>

二，mysql分表和分区有什么区别呢

1�Q�实现方式上

a�Q�，mysql的分表是真正的分表，一张表分成很多表后�Q�每一个小表都是完正的一张表�Q�都对应三个文�g�Q�一�?MYD数据文�g�Q?MYI索引文�g�Q?frm表结构文件�?/p>

[root@BlackGhost test]# ls |grep user
alluser.MRG
alluser.frm
user1.MYD
user1.MYI
user1.frm
user2.MYD
user2.MYI
user2.frm

[root@BlackGhost test]# ls |grep user alluser.MRG alluser.frm user1.MYD user1.MYI user1.frm user2.MYD user2.MYI user2.frm

��单说明一下，上面的分表呢是利用了merge存储引擎�Q�分表的一�U�）�Q�alluser是总表�Q�下面有二个分表�Q�user1�Q�user2。他们二个都是独立的表，取数据的时候，我们可以通过总表来取。这里总表是没�?MYD,.MYI�q�二个文件的�Q�也��是��_��总表他不是一张表�Q�没有数据，数据都放在分表里面。我们来看看.MRG到底是什么东�?/p>

[root@BlackGhost test]# cat alluser.MRG |more
user1
user2
#INSERT_METHOD=LAST

[root@BlackGhost test]# cat alluser.MRG |more user1 user2 #INSERT_METHOD=LAST

从上面我们可以看出，alluser.MRG里面��存了一些分表的关系�Q�以及插入数据的方式。可以把总表理解成一个外壻I��或者是联接池�?/p>

b�Q�，分区不一��P��一张大表进行分区后�Q�他�q�是一张表�Q�不会变成二张表�Q�但是他存放数据的区块变多了�?/p>

[root@BlackGhost test]# ls |grep aa
aa#P#p1.MYD
aa#P#p1.MYI
aa#P#p3.MYD
aa#P#p3.MYI
aa.frm
aa.par

[root@BlackGhost test]# ls |grep aa aa#P#p1.MYD aa#P#p1.MYI aa#P#p3.MYD aa#P#p3.MYI aa.frm aa.par

从上面我们可以看出，aa�q�张表，分�ؓ二个区，p1和p3�Q�本来是三个区，被我删了一个区。我们都知道一张表对应三个文�g.MYD,.MYI,.frm。分区呢�Ҏ��一定的规则把数据文件和索引文�g�q�行了分�Ԍ��q�多��Z��一�?par文�g�Q�打开.par文�g后你可以看出他记录了�Q�这张表的分��Z��息，根分表中�?MRG有点像。分区后�Q�还是一张，而不是多张表�?/p>

2�Q�数据处理上

a�Q�，分表后，数据都是存放在分表里�Q�总表只是一个外壻I��存取数据发生在一个一个的分表里面。看下面的例子：

select * from alluser where id='12'表面上看�Q�是对表alluser�q�行操作的，其实不是的。是对alluser里面的分表进行了操作�?/p>

b�Q�，分区呢，不存在分表的概念�Q�分区只不过把存放数据的文�g分成了许多小块，分区后的表呢�Q�还是一张表。数据处理还是由自己来完成�?/p>

3�Q�提高性能�?/strong>

a�Q�，分表后，单表的�ƈ发能力提高了�Q�磁盘I/O性能也提高了。�ƈ发能力�ؓ什么提高了呢，因�ؓ查寻一�ơ所��q��旉��变短了，如果出现高�ƈ发的话，总表可以�Ҏ��不同的查询，��ƈ发压力分��C��同的��表里面。磁盘I/O性能怎么搞高了呢�Q�本来一个非常大�?MYD文�g现在也分摊到各个��表�?MYD中去了�?/p>

b�Q�，mysql提出了分区的概念�Q�我觉得��想�H�破��盘I/O瓉��Q�想提高��盘的读写能力，来增加mysql性能�?br style="padding: 0px; margin: 0px;" />在这一点上�Q�分区和分表的测重点不同�Q�分表重�Ҏ��存取数据�Ӟ��如何提高mysql�q�发能力上；而分区呢�Q�如何突破磁盘的��d��能力�Q�从而达到提高mysql性能的目的�?/p>

4�Q�，实现的难易度�?/strong>

a�Q�，分表的方法有很多�Q�用merge来分表，是最��单的一�U�方式。这�U�方式根分区难易度差不多�Q��ƈ且对�E�序代码来说可以做到透明的。如果是用其他分表方式就比分区麻烦了�?/p>

b�Q�，分区实现是比较简单的�Q�徏立分��Q�根建��^常的表没什么区别，�q�且对开代码端来说是透明的�?/p>

三，mysql分表和分区有什么联�p�d��

1�Q�都能提高mysql的性高�Q�在高�ƈ发状态下都有一个良好的表面�?/p>

2�Q�分表和分区不矛盾，可以�怺�配合的，对于那些大访问量�Q��ƈ且表数据比较多的表，我们可以采取分表和分区结合的方式�Q�如果merge�q�种分表方式�Q�不能和分区配合的话�Q�可以用其他的分表试�Q�，讉K��量不大，但是表数据很多的表，我们可以采取分区的方式等�?/p>

paulwong 2013-05-07 09:19 发表评论