MySQL调优（一）未完成

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Server 处理 Client 的请求过程

image-20210514091715754

性能监控

SHOW PROFILE 分析SQL执行耗时

  1. 开启分析

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    set profiling=1;

  2. 运行查询语句

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    select * from user;
    select * from category;

  3. 查看查询语句耗时

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    show profiles;
    +----------+------------+------------------------+
    | Query_ID | Duration   | Query                  |
    +----------+------------+------------------------+
    |        1 | 0.00019575 | select * from user     |
    |        2 | 0.00018800 | select * from category |
    +----------+------------+------------------------+

  4. 查询单个语句的详细信息

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    show profile for query 1;
    +----------------------+----------+
    | Status               | Duration |
    +----------------------+----------+
    | starting             | 0.000052 |
    | checking permissions | 0.000005 |
    | Opening tables       | 0.000014 |
    | init                 | 0.000014 |
    | System lock          | 0.000006 |
    | optimizing           | 0.000003 |
    | statistics           | 0.000008 |
    | preparing            | 0.000006 |
    | executing            | 0.000002 |
    | Sending data         | 0.000034 |
    | end                  | 0.000003 |
    | query end            | 0.000004 |
    | closing tables       | 0.000006 |
    | freeing items        | 0.000031 |
    | cleaning up          | 0.000008 |
    +----------------------+----------+

  5. 查看sql相关的所有分析【主要看i/o与cpu】

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    show profile all for query 1 \G;
    *************************** 1. row ***************************
                 Status: starting
               Duration: 0.000052
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: NULL
            Source_file: NULL
            Source_line: NULL
    *************************** 2. row ***************************
                 Status: checking permissions
               Duration: 0.000005
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_parse.cc
            Source_line: 5266
    *************************** 3. row ***************************
                 Status: Opening tables
               Duration: 0.000014
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_base.cc
            Source_line: 5018
    *************************** 4. row ***************************
                 Status: init
               Duration: 0.000014
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_select.cc
            Source_line: 1050
    *************************** 5. row ***************************
                 Status: System lock
               Duration: 0.000006
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: lock.cc
            Source_line: 304
    *************************** 6. row ***************************
                 Status: optimizing
               Duration: 0.000003
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_optimizer.cc
            Source_line: 138
    *************************** 7. row ***************************
                 Status: statistics
               Duration: 0.000008
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_optimizer.cc
            Source_line: 362
    *************************** 8. row ***************************
                 Status: preparing
               Duration: 0.000006
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_optimizer.cc
            Source_line: 485
    *************************** 9. row ***************************
                 Status: executing
               Duration: 0.000002
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_executor.cc
            Source_line: 110
    *************************** 10. row ***************************
                 Status: Sending data
               Duration: 0.000034
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_executor.cc
            Source_line: 190
    *************************** 11. row ***************************
                 Status: end
               Duration: 0.000003
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_select.cc
            Source_line: 1105
    *************************** 12. row ***************************
                 Status: query end
               Duration: 0.000004
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_parse.cc
            Source_line: 4965
    *************************** 13. row ***************************
                 Status: closing tables
               Duration: 0.000006
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_parse.cc
            Source_line: 5013
    *************************** 14. row ***************************
                 Status: freeing items
               Duration: 0.000031
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_parse.cc
            Source_line: 6404
    *************************** 15. row ***************************
                 Status: cleaning up
               Duration: 0.000008
               CPU_user: 0.000000
             CPU_system: 0.000000
      Context_voluntary: NULL
    Context_involuntary: NULL
           Block_ops_in: NULL
          Block_ops_out: NULL
          Messages_sent: NULL
      Messages_received: NULL
      Page_faults_major: NULL
      Page_faults_minor: NULL
                  Swaps: NULL
        Source_function: <unknown>
            Source_file: sql_parse.cc
            Source_line: 1772

  6. 关闭分析

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    set profiling=1;

MySQL Performance Schema

详细可以查看官方文档

查看线程连接个数 SHOW PROCESSLIST

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+----+------+-----------------+----------+---------+------+-------+------------------+
| Id | User | Host            | db       | Command | Time | State | Info             |
+----+------+-----------------+----------+---------+------+-------+------------------+
| 45 | root | localhost:11156 | bugstack | Sleep   |  210 |       | NULL             |
| 46 | root | localhost:13537 | NULL     | Query   |    0 | init  | show processlist |
+----+------+-----------------+----------+---------+------+-------+------------------+
  • id：表示session id
  • user：表示操作的用户
  • host：表示操作的主机
  • db：表示操作的数据库
  • command：表示命令类型
  • info：表示详细的sql语句
  • time：表示相应命令执行时间
  • state：表示命令执行状态