On CentOS 7 server using MariaDB 10.1.21 site stopped working with following error.
[root@freexblogs ~]# mysql -u freexblogs -pSHwz5DST@jBaxr ERROR 1040 (08004): Too many connections [root@freexblogs ~]#
This is because by default MySQL only allow 151 connections
[root@freexblogs ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 22277 Server version: 10.1.21-MariaDB MariaDB Server Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> show variables like '%connection%'; +---------------------------+-----------------+ | Variable_name | Value | +---------------------------+-----------------+ | character_set_connection | utf8 | | collation_connection | utf8_general_ci | | default_master_connection | | | extra_max_connections | 1 | | max_connections | 151 | | max_user_connections | 0 | +---------------------------+-----------------+ 6 rows in set (0.00 sec) MariaDB [(none)]> Bye [root@freexblogs ~]#
To fix, edit file
vi /etc/my.cnf.d/server.cnf
Add max_connections = 500 under [mysqld] section.
[root@freexblogs ~]# cat /etc/my.cnf.d/server.cnf # # These groups are read by MariaDB server. # Use it for options that only the server (but not clients) should see # # See the examples of server my.cnf files in /usr/share/mysql/ # # this is read by the standalone daemon and embedded servers [server] # this is only for the mysqld standalone daemon [mysqld] max_connections = 500 # # * Galera-related settings # [galera] # Mandatory settings #wsrep_on=ON #wsrep_provider= #wsrep_cluster_address= #binlog_format=row #default_storage_engine=InnoDB #innodb_autoinc_lock_mode=2 # # Allow server to accept connections on all interfaces. # #bind-address=0.0.0.0 # # Optional setting #wsrep_slave_threads=1 #innodb_flush_log_at_trx_commit=0 # this is only for embedded server [embedded] # This group is only read by MariaDB servers, not by MySQL. # If you use the same .cnf file for MySQL and MariaDB, # you can put MariaDB-only options here [mariadb] # This group is only read by MariaDB-10.1 servers. # If you use the same .cnf file for MariaDB of different versions, # use this group for options that older servers don't understand [mariadb-10.1] You have mail in /var/spool/mail/root [root@freexblogs ~]#
Now restart MySQL
service mysql restart
Verify max_connections limit increased.
[root@freexblogs ~]# mysql Welcome to the MariaDB monitor. Commands end with ; or \g. Your MariaDB connection id is 489 Server version: 10.1.21-MariaDB MariaDB Server Copyright (c) 2000, 2016, Oracle, MariaDB Corporation Ab and others. Type 'help;' or '\h' for help. Type '\c' to clear the current input statement. MariaDB [(none)]> show variables like 'max_connections%'; +-----------------+-------+ | Variable_name | Value | +-----------------+-------+ | max_connections | 500 | +-----------------+-------+ 1 row in set (0.00 sec) MariaDB [(none)]> Bye [root@freexblogs ~]#
