Mysql之参数优化了解
一、优化的配置文件
[client]
port=3306
socket=/tmp/MySQL.sock
[mysqld]
# Remove leading # and set to the amount of RAM for the most important data
# cache in MySQL. Start at 70% of total RAM for dedicated server, else 10%.
innodb_buffer_pool_size = 3G
# Remove leading # to turn on a very important data integrity option: logging
# changes to the binary log between backups.
# log_bin
# These are commonly set, remove the # and set as required.
user = mysql
basedir = /app/mysql
datadir = /app/mysql/data
port=3307
server-id = 1
socket=/tmp/mysql.sock
#允许创建函数
log_bin_trust_function_creators = 1
character-set-server = utf8
#log-error = /var/log/mysql/error.log
#pid-file = /var/log/mysql/mysql.pid
general_log = 1
skip-name-resolve
#skip-networking
back_log = 300
max_connections = 1000
max_connect_errors = 6000
open_files_limit = 65535
table_open_cache = 4096
max_allowed_packet = 100M
binlog_cache_size = 10M
max_heap_table_size = 32M
tmp_table_size = 64M
read_buffer_size = 8M
read_rnd_buffer_size = 8M
sort_buffer_size = 8M
join_buffer_size = 128M
key_buffer_size = 8M
thread_cache_size = 64
query_cache_type = 1
query_cache_size = 128M
query_cache_limit = 2M
ft_min_word_len = 4
log_bin = mysql-bin
binlog_format = mixed
expire_logs_days = 30
performance_schema = 0
explicit_defaults_for_timestamp
lower_case_table_names = 1
myisam_sort_buffer_size = 8M
myisam_repair_threads = 1
interactive_timeout = 28800
wait_timeout = 28800
# Remove leading # to set options mainly useful for reporting servers.
# The server defaults are faster for transactions and fast SELECTs.
# Adjust sizes as needed, experiment to find the optimal values.
# join_buffer_size = 128M
# sort_buffer_size = 2M
# read_rnd_buffer_size = 2M
# Disabling symbolic-links is recommended to prevent assorted security risks
symbolic-links=0
# Recommended in standard MySQL setup
sql_mode=NO_ENGINE_SUBSTITUTION,NO_AUTO_CREATE_USER,STRICT_TRANS_TABLES
[mysqldump]
quick
max_allowed_packet = 16M二、参数解释查看
max_connections = 1000 #客户端连接数
max_connect_errors = 6000 #错误连接数
-----
mysql> show variables like '%conn%';
+-----------------------------------------------+-----------------+
| Variable_name | Value |
+-----------------------------------------------+-----------------+
| character_set_connection | utf8 |
| collation_connection | utf8_general_ci |
| connect_timeout | 10 |
| disconnect_on_expired_password | ON |
| init_connect | |
| max_connect_errors | 6000 |
| max_connections | 1000 |
| max_user_connections | 0 |
| performance_schema_session_connect_attrs_size | 0 |
+-----------------------------------------------+-----------------+
9 rows in set (0.01 sec)
-----
查看系统当前连接数
mysql> show status like 'Threads%';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| Threads_cached | 9 |
| Threads_connected | 3 | #连接数
| Threads_created | 12 |
| Threads_running | 2 |
+-------------------+-------+
4 rows in set (0.01 sec)
----------------------------------------------------------------------------------------------------
table_open_cache=4096
#通常此值需要大于Opened_tables值
查看当前Opened_tables值
mysql> show status like '%Opened%';
+--------------------------+-------+
| Variable_name | Value |
+--------------------------+-------+
| Opened_files | 2979 |
| Opened_table_definitions | 1 |
| Opened_tables | 1 | #对比
+--------------------------+-------+
3 rows in set (0.00 sec)
----------------------------------------------------------------------------------------------------
max_heap_table_size = 32M
tmp_table_size = 64M
#参考文档：https://www.jb51.net/article/85341.htm
mysql> show status like '%created_tmp%'; #查看当前情况
+-------------------------+-------+
| Variable_name | Value |
+-------------------------+-------+
| Created_tmp_disk_tables | 2921 |
| Created_tmp_files | 11 |
| Created_tmp_tables | 8476 |
+-------------------------+-------+
3 rows in set (0.00 sec)
----------------------------------------------------------------------------------------------------
read_buffer_size = 8M
read_rnd_buffer_size = 8M
sort_buffer_size = 8M
join_buffer_size = 128M
key_buffer_size = 8M
参考文档：https://www.jb51.net/article/84170.htm
----------------------------------------------------------------------------------------------------
innodb_buffer_pool_size = 3G #最大建议值为内存的75%
---------------------------------------------------------------------------------------------------
thread_cache_size = 64
系统参数：
mysql> show global status like 'Threads_%';
+-------------------+-------+
| Variable_name | Value |
+-------------------+-------+
| Threads_cached | 9 | #这就是thread_cache_size
| Threads_connected | 3 |
| Threads_created | 12 |
| Threads_running | 2 |
+-------------------+-------+
4 rows in set (0.00 sec)
参考文档：https://www.jianshu.com/p/47adb747652d
---------------------------------------------------------------------------------------------------
query_cache_type = 1
query_cache_size = 128M
query_cache_limit = 2M
mysql> SHOW VARIABLES LIKE 'have_query_cache';
+------------------+-------+
| Variable_name | Value |
+------------------+-------+
| have_query_cache | YES |
+------------------+-------+
1 row in set (0.00 sec)
mysql> SHOW STATUS LIKE 'Qcache%';
+-------------------------+-----------+
| Variable_name | Value |
+-------------------------+-----------+
| Qcache_free_blocks | 1 |
| Qcache_free_memory | 134200384 |
| Qcache_hits | 0 |
| Qcache_inserts | 0 |
| Qcache_lowmem_prunes | 0 |
| Qcache_not_cached | 6 |
| Qcache_queries_in_cache | 0 |
| Qcache_total_blocks | 1 |
+-------------------------+-----------+
8 rows in set (0.00 sec)
参考文档：https://blog.csdn.net/u014044812/article/details/78924315当前标题：Mysql之参数优化了解
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