如何定位mysql性能问题
1.首先利用系统工具,定位问题[ top | nmon | dstat -dcnml | orzdba ]: top命令查看各个进程的资源占用情况,各个指标依次解读如下【top f|1 --help】 : 第一行:当前系统时间,系统运行时长,当前登录用户数,系统负载(任务队列的平均长度,三个数值分别
1.首先利用系统工具,定位问题[ top | nmon | dstat -dcnml | orzdba ]:
top命令查看各个进程的资源占用情况,各个指标依次解读如下【top f|1 --help】 :
第一行:当前系统时间,系统运行时长,当前登录用户数,系统负载(任务队列的平均长度,三个数值分别为1,5,15分钟)【系统负载不要超过cpu的核数】
第二行:进程总数,正在运行的进程数据,睡眠的进程数,停止的进程数,僵尸进程数
第三行:用户空间占用cpu百分比,,内核空间占用cpu百分比,用户进程空间改变过优先级的进程占cpu的百分比,空闲cpu百分比,等待输入输出cpu百分比,,,
第四行:物理内存总数,使用的物理内存总数,空闲内存总量,用作内核缓存的内存量 【70%】
第五行:交换区总量,使用的交换区总量,空闲交换区总量,缓冲的交换区总量 【不要使用交换分区】
pid 进程id
ppid 父进程id
Ruser real user name
uid 进程所有者用户id
user进程所有者用户名
group 进程所有者组名
tty 启动进程的终端
pr 优先级
NI 优先级(负值表示优先级高,正值表示优先级低)
p 最后使用的cpu,仅在cpu多的情况下
%CPU 上次更新到现在,cpu占用百分比
TIME 系统使用的cpu时间总计(秒)
TIME+ ~(1/100秒)
%MEM 进程使用的物理内存百分比
VIRT 进程使用的虚拟内存总量 VIRT=SWAP+RES
SWAP 进程使用的虚拟内存总量 VIRT=SWAP+RES
RES 进程使用的虚拟内存中,被换出的大小 进程使用的、未被换出的物理内存大小RES=CODE+DATA
CODE可执行代码占用物理内存大小
DATA 可执行代码以外的部分(数据段+栈)占用的物理内存大小
SHR 共享内存大小
nFLT 页面错误次数
nDRT 最后一次写入到现在,被修改过的页面数
S 进程状态 D=不可中断的睡眠状态 R=运行 S=睡眠 T=跟踪/停止 Z=僵尸进程
COMMAND 命令行,命令
WCHAN 若该进程在睡眠,则显示睡眠中的,系统函数名
FLAGS 任务标志
2.查看网络问题
netstat -i 1 是否存在丢包,网络错误问题
iftop 【D S】查看进程流量流向 按S切换是否显示本机的端口信息;按D切换是否显示远端目标主机的端口信息;
3.查看io流向
iostat -x 2
iotop 查看进程io走向
dd if=/dev/zero of=/data1/test bs=64k count=16k conv=fsync 目前生产环境EMC正常写入速度 565 MB/秒
dd if=/data1/test bs=64k |dd of=/dev/null 目前生产环境EMC正常读取速度 675 MB/秒
4.. query压力情况
mysqladmin -uroot -P3309 ext -ri 1 |grep -i queries
5.查看是否有锁等待
select r.trx_id waiting_trx_id,
r.trx_mysql_thread_id waiting_thread,
r.trx_query waiting_query,
b.trx_id blocking_trx_id,
b.trx_mysql_thread_id blocking_thread,
b.trx_query blocking_query
from information_schema.innodb_lock_waits w
INNER JOIN information_schema.innodb_trx b
ON b.trx_id = w.blocking_trx_id
INNER JOIN information_schema.innodb_trx r
ON r.trx_id = w.requesting_trx_idG;
6.查看innodb状态
show engine innodb statusG;
7.从监控工具中查看,历史记录
zabbix

Hot AI Tools

Undresser.AI Undress
AI-powered app for creating realistic nude photos

AI Clothes Remover
Online AI tool for removing clothes from photos.

Undress AI Tool
Undress images for free

Clothoff.io
AI clothes remover

Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Article

Hot Tools

Notepad++7.3.1
Easy-to-use and free code editor

SublimeText3 Chinese version
Chinese version, very easy to use

Zend Studio 13.0.1
Powerful PHP integrated development environment

Dreamweaver CS6
Visual web development tools

SublimeText3 Mac version
God-level code editing software (SublimeText3)

Hot Topics

MySQL is an open source relational database management system, mainly used to store and retrieve data quickly and reliably. Its working principle includes client requests, query resolution, execution of queries and return results. Examples of usage include creating tables, inserting and querying data, and advanced features such as JOIN operations. Common errors involve SQL syntax, data types, and permissions, and optimization suggestions include the use of indexes, optimized queries, and partitioning of tables.

MySQL's position in databases and programming is very important. It is an open source relational database management system that is widely used in various application scenarios. 1) MySQL provides efficient data storage, organization and retrieval functions, supporting Web, mobile and enterprise-level systems. 2) It uses a client-server architecture, supports multiple storage engines and index optimization. 3) Basic usages include creating tables and inserting data, and advanced usages involve multi-table JOINs and complex queries. 4) Frequently asked questions such as SQL syntax errors and performance issues can be debugged through the EXPLAIN command and slow query log. 5) Performance optimization methods include rational use of indexes, optimized query and use of caches. Best practices include using transactions and PreparedStatemen

MySQL is chosen for its performance, reliability, ease of use, and community support. 1.MySQL provides efficient data storage and retrieval functions, supporting multiple data types and advanced query operations. 2. Adopt client-server architecture and multiple storage engines to support transaction and query optimization. 3. Easy to use, supports a variety of operating systems and programming languages. 4. Have strong community support and provide rich resources and solutions.

Apache connects to a database requires the following steps: Install the database driver. Configure the web.xml file to create a connection pool. Create a JDBC data source and specify the connection settings. Use the JDBC API to access the database from Java code, including getting connections, creating statements, binding parameters, executing queries or updates, and processing results.

The process of starting MySQL in Docker consists of the following steps: Pull the MySQL image to create and start the container, set the root user password, and map the port verification connection Create the database and the user grants all permissions to the database

The main role of MySQL in web applications is to store and manage data. 1.MySQL efficiently processes user information, product catalogs, transaction records and other data. 2. Through SQL query, developers can extract information from the database to generate dynamic content. 3.MySQL works based on the client-server model to ensure acceptable query speed.

The key to installing MySQL elegantly is to add the official MySQL repository. The specific steps are as follows: Download the MySQL official GPG key to prevent phishing attacks. Add MySQL repository file: rpm -Uvh https://dev.mysql.com/get/mysql80-community-release-el7-3.noarch.rpm Update yum repository cache: yum update installation MySQL: yum install mysql-server startup MySQL service: systemctl start mysqld set up booting

Laravel is a PHP framework for easy building of web applications. It provides a range of powerful features including: Installation: Install the Laravel CLI globally with Composer and create applications in the project directory. Routing: Define the relationship between the URL and the handler in routes/web.php. View: Create a view in resources/views to render the application's interface. Database Integration: Provides out-of-the-box integration with databases such as MySQL and uses migration to create and modify tables. Model and Controller: The model represents the database entity and the controller processes HTTP requests.
