| Command-Line Format | --wait-timeout=# | ||
| System Variable | Name | wait_timeout | |
| Variable Scope | Global, Session | ||
| Dynamic Variable | Yes | ||
| Permitted Values (Windows) | Type | integer | |
| Default | 28800 | ||
| Min Value | 1 | ||
| Max Value | 2147483 | ||
| Permitted Values (Other) | Type | integer | |
| Default | 28800 | ||
| Min Value | 1 | ||
| Max Value | 31536000 | ||
這個參數指的是數據庫系統在關閉它之前，服務器等待非交互式連接上的活動的秒數。
interactive_timeout
| Command-Line Format | --interactive-timeout=# | ||
| System Variable | Name | interactive_timeout | |
| Variable Scope | Global, Session | ||
| Dynamic Variable | Yes | ||
| Permitted Values | Type | integer | |
| Default | 28800 | ||
| Min Value | 1 | ||
這個參數指的是在關閉交互式連接之前，服務器等待活動的秒數
Warning:警告這兩個參數建議一起調節，能夠避免一些坑。
本文的兩個參數值采用的是默認值
mysql> show global variables like '%timeout%'; +----------------------------+----------+ | Variable_name | Value | +----------------------------+----------+ | connect_timeout | 10 | | delayed_insert_timeout | 300 | | innodb_lock_wait_timeout | 50 | | innodb_rollback_on_timeout | OFF | |interactive_timeout | 28800 | | lock_wait_timeout | 31536000 | | net_read_timeout | 30 | | net_write_timeout | 60 | | slave_net_timeout | 3600 | |wait_timeout | 28800 | +----------------------------+----------+ 10 rows in set (0.01 sec)
另外在數據庫中，我們重點關注下這兩個參數，看看什么情況下Aborted_clients會提升，什么情況下Aborted_connects 會提升
mysql>show global status like 'aborted%'; +------------------+-------+ |Variable_name | Value | +------------------+-------+ |Aborted_clients | 19 | |Aborted_connects | 0 | +------------------+-------+ 2 rows inset (0.00 sec)
Part4:案例1
這里我故意輸入錯誤的密碼5次，來看下數據庫的error log和Aborted的哪個參數記載了這一問題
[root@HE3~]# mysql -uroot -pwrongpass -h127.0.0.1 ERROR 1045 (28000): Access denied for user 'root'@'127.0.0.1' (using password: YES) [root@HE3~]# mysql -uroot -pwrongpass -h127.0.0.1 ERROR 1045 (28000): Access denied for user 'root'@'127.0.0.1' (using password: YES) [root@HE3~]# mysql -uroot -pwrongpass -h127.0.0.1 ERROR 1045 (28000): Access denied for user 'root'@'127.0.0.1' (using password: YES) [root@HE3~]# mysql -uroot -pwrongpass -h127.0.0.1 ERROR 1045 (28000): Access denied for user 'root'@'127.0.0.1' (using password: YES) [root@HE3~]# mysql -uroot -pwrongpass -h127.0.0.1 ERROR 1045 (28000): Access denied for user 'root'@'127.0.0.1' (using password: YES)
可以看出，這里的Aborted_connects 記錄了密碼錯誤的這一問題
mysql>show global status like 'aborted%'; +------------------+-------+ |Variable_name | Value | +------------------+-------+ |Aborted_clients | 19 | |Aborted_connects | 5 | +------------------+-------+ 2 rows inset (0.00 sec)
error log中，也記載了這類密碼輸錯的信息
[Warning] Access denied for user'root'@'127.0.0.1' (using password: YES) [Warning] Access denied for user 'root'@'127.0.0.1' (using password:YES) [Warning] Access denied for user 'root'@'127.0.0.1' (using password:YES) [Warning] Access denied for user 'root'@'127.0.0.1' (using password:YES) [Warning] Access denied for user 'root'@'127.0.0.1' (using password:YES)
Part5:案例2
接下來我們看下文章第三節提到的兩個重點參數對數據庫連接的行為影響
這里我們將這兩個參數均配置為10秒
mysql>set global wait_timeout=10; Query OK,0 rows affected (0.00 sec) mysql>set global interactive_timeout=10; Query OK,0 rows affected (0.00 sec) mysql>show processlist; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect... Connection id: 79 Current database: *** NONE *** +----+------+-----------------+------+---------+------+-------+------------------+ | Id |User | Host | db | Command | Time | State | Info | +----+------+-----------------+------+---------+------+-------+------------------+ | 79 |root | 127.0.0.1:42016 | NULL | Query | 0 | NULL | show processlist | +----+------+-----------------+------+---------+------+-------+------------------+ 1 row in set (0.00 sec)
這里三次操作，可以看到clients數上升，這是由于timeout參數控制的，已經連接上數據的連接被殺掉。
mysql>show global status like 'aborted%'; ERROR 2006 (HY000): MySQL server has gone away No connection. Trying to reconnect... Connection id: 81 Current database: *** NONE *** +------------------+-------+ |Variable_name | Value | +------------------+-------+ |Aborted_clients | 22 | |Aborted_connects | 5 | +------------------+-------+ 2 rows in set (0.01 sec)
error log中記載的是
[Warning] Aborted connection 81 to db: 'unconnected' user: 'root' host: '127.0.0.1' (Got timeout reading communication packets) [Warning] Aborted connection 78 to db: 'unconnected' user: 'root' host: '127.0.0.1' (Got timeout reading communication packets) [Warning] Aborted connection 79 to db: 'unconnected' user: 'root' host: '127.0.0.1' (Got timeout reading communication packets)
Part6:案例3
在這個案例中我們看下最大連接數對數據庫連接的行為影響
mysql>show global variables like 'max_conn%'; +--------------------+-------+ |Variable_name | Value | +--------------------+-------+ |max_connect_errors | 1000 | |max_connections | 1024 | +--------------------+-------+ 2 rows in set (0.00 sec) mysql>set global max_connections=2; Query OK,0 rows affected (0.00 sec)
這里看到爆出了連接數過多的問題
[root@HE3~]# mysql -uroot -pMANAGER -h127.0.0.1 ERROR 1040 (HY000): Too many connections
而錯誤日志沒有任何記錄
Part7:案例4
第三方工具navicat select結果沒有出來的時候選擇停止則出現
clients上漲
mysql>show global status like 'aborted%'; +------------------+-------+ |Variable_name | Value | +------------------+-------+ |Aborted_clients | 28 | |Aborted_connects | 10 | +------------------+-------+ 2 rows in set (0.00 sec)
error log日志記錄
170626 16:26:56 [Warning] Aborted connection 109 to db: 'helei1' user: 'sys_admin' host: '192.168.1.1' (Got an error writing communication packets)
Part8:原因總結
總結
通過這4個案例，我們能夠了解到，Aborted_clients、和Aborted_connects的區別，以及什么情況下會爆出什么樣的錯誤日志，文章第二節中的幾個Aborted錯誤是常見的錯誤，這類錯誤出現的時候腦海里要有一個理論知識，知道什么情況下，會出現什么樣的錯誤，以便快速定位問題。由于筆者的水平有限，編寫時間也很倉促，文中難免會出現一些錯誤或者不準確的地方，不妥之處懇請讀者批評指正。
好了，以上就是這篇文章的全部內容了，希望本文的內容對大家的學習或者工作能帶來一定的幫助，如果有疑問大家可以留言交流，謝謝大家對腳本之家的支持。
