Technology Sharing

한어Русский языкEnglishFrançaisIndonesianSanskrit日本語DeutschPortuguêsΕλληνικάespañolItalianoSuomalainenLatina

1. Too many connections

---

Operating environment: Winows11, Phpstudy V8.1.1.3, MySQL 5.7.26

There is a limit on the number of MySQL connections at the same time. When the limit is exceeded, the following error message will be displayed:

1. 1040 - Too many connections

View the current maximum number of connections

1. mysql> show variables like '%max_connection%';
2. +-----------------+-------+
3. | Variable_name | Value |
4. +-----------------+-------+
5. | max_connections | 100 |
6. +-----------------+-------+

Modify the maximum number of connections

1. set global max_connections=500;

2. MySQL server has gone away

---

Operating environment: Winows11 + Phpstudy V8.1.1.3

After entering the MySQL command line, if you connect to the MySQL service for a long time without performing any operation, the MySQL service will be automatically disconnected. When you perform the operation again, the following prompt will appear:

1. ERROR 2006 (HY000): MySQL server has gone away
2. No connection. Trying to reconnect...
3. Connection id: 2
4. Current database: liang

Check out the two ways to write the timeout (the default timeout is 120 seconds):

1. select @@wait_timeout;
2. show variables like 'wait_timeout';

The current session timeout is set to 700 seconds

1. set @@wait_timeout = 700;