标签归档：MySQL

— 创建用户并设置密码(默认密码有复杂度要求，这里使用新的验证方式 caching_sha2_password )

CREATE USER 'root'@'%' IDENTIFIED WITH caching_sha2_password BY 'Aa#111111111';

— 授予root权限

GRANT ALL ON *.* TO 'root'@'%';
UPDATE `mysql`.`user` SET `Grant_priv` = 'y' WHERE (`Host` = '%') and (`User` = 'root');

然后重启下MySQL就好了

如果root@%已经存在了则需要修改密码：

alter user 'root'@'%' identified by '123456';

其他配置：

不强制要求特殊字符：set global validate_password.special_char_count=0;

简单实现MySQL负载低时才继续运行任务，负载高的时候睡眠

public static function runSleep($sec = 10, $echo = null) {
    while (true) {
        $result = NoThingModel::getInstance()->db->select("show status like 'Threads_running'", [], false);
        $result = reset($result);
        if ($result) {
            if ($result->Variable_name == 'Threads_running') {
                if ($result->Value > 10) {
                    if ($echo) {
                        echo "sleep 10\n";
                    }
                    sleep($sec);
                } else {
                    break;
                }
            } else {
                break;
            }
        } else {
            break;
        }
    }
}

MySQL二进制日志清理

查看过期天数

show variables like ‘%logs%’;

2. 设置过期天数（最大值为99）

set global expire_logs_days = 99;

MySQL8.0 支持binlog_expire_logs_seconds参数，顾名思义就是日志过期秒数。

自动二进制日志文件删除的天数。默认值为0，表示“不自动删除”。可能的删除发生在启动时和二进制日志刷新。

2.1 生效问题

flush logs;

如果你发现设置没有生效，可能需要执行此命令。

3. 查看现有的日志文件

SHOW BINARY LOGS;

4. 手动清理较旧日志

PURGE BINARY LOGS TO ‘mysql-bin.000007’;

将mysql-bin.000007以前的日志清理掉，又或者

PURGE BINARY LOGS BEFORE ‘2018-01-06 12:12:12’;

将2018-01-06 12:12:12以前的日志清理掉

5. 修改MySQL配置文件

expire_logs_days = 99

create table和主从复制一坑

正确：CREATE TABLE `chapter_lock_reason` ( `id` INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY (`id`) );
错误的方式：CREATE TABLE xxx.`chapter_lock_reason` ( `id` INT(11) NOT NULL AUTO_INCREMENT PRIMARY KEY (`id`) );

MySQL ARCHIVE 引擎，从库突然Can’t write; duplicate key in table ‘nopay_record” on query.

这是ARCHIVE引擎的BUG

Error ‘Can’t write; duplicate key in table ‘nopay_record” on query. Default database: ‘doufu’. Query: ‘insert into `nopay_record` (`user_id`, `novel_id`, `chapter_id`, `channel`, `created_at`) values (3927416, 365027, 2499984, NULL, ‘2017-12-29 23:38:01′)’

表结构:

CREATE TABLE `nopay_record` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`user_id` int(11) NOT NULL,
`novel_id` int(11) NOT NULL,
`chapter_id` int(11) NOT NULL,
`channel` tinyint(4) DEFAULT NULL,
`created_at` timestamp NOT NULL DEFAULT ‘0000-00-00 00:00:00’,
`updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
PRIMARY KEY (`id`)
) ENGINE=ARCHIVE AUTO_INCREMENT=440357 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_bin;

改成innodb吧

[link]MySQL · BUG分析 · Rename table 死锁分析

MySQL · BUG分析 · Rename table 死锁分析

xtrabackup 快速增量备份教程

xtrabackup –backup –compress –target-dir=/mysqlbackup/full –user=aaa –host=hostname –password=xxxx –databases=ggggg

xtrabackup –backup –compress –target-dir=/mysqlbackup/incr –incremental-basedir=/mysqlbackup/full –user=aaa –host=hostname –password=xxxx –databases=ggggg

–compress 压缩

MySQL UPDATE JOIN

JOIN似乎不太满足这里的需求子查询更好

UPDATE novel 
SET 
    chat_num = (SELECT 
            COUNT(*)
        FROM
            chats
        WHERE
            novel_id = ? AND status = 1)
WHERE
    id = ?

UPDATE JOIN 似乎无法使用limit

UPDATE pay_record
        JOIN
    article_info ON article_info.id = pay_record.object_id 
SET 
    novel_id = special_id
WHERE
    ISNULL(novel_id) AND pay_record.id = 17;

杨龙

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