Cara menggunakan mysql max_connections

mysql max connections limit check query commanding

mysql connection limit allowed

mysql -u root -p

Table of Contents

• mysql max connections limit check query commanding
• mysql connection limit allowed
• To view max Reached Mysql Connections since the Server start
• To check active connections in mysql concurrent
• to list all connections
• mysql max connections recommended settings (how to choose)
• mysql max connections calculator
• Update max connection limit in mysql.conf
• Check max used connections by mysql previous
• Aborted connection mysql
• Show threads currently running on MySQL DB instance
• increasing thread_cache_size to allow more simultaneous users
• mysql too many connections fix
• What is maximum connection?
• How does MySQL determine max connections?
• How do I fix MySQL max connections?
• What is total connections in MySQL?

Password:

mysql> SHOW VARIABLES LIKE “max_connections”;

SHOW VARIABLES LIKE “max_connections”;

+—————–+——-+
| Variable_name | Value |
+—————–+——-+
| max_connections | 151 | default
+—————–+——-+
1 row in set (0.01 sec)

To view max Reached Mysql Connections since the Server start

SHOW GLOBAL STATUS LIKE ‘max_use%’;

+—————————+———————+
| Variable_name | Value |
+—————————+———————+
| Max_used_connections | 38 |
| Max_used_connections_time | 2021-06-08 02:39:27 |
+—————————+———————+

mysql> SHOW STATUS WHERE `variable_name` = ‘Max_used_connections’;
+———————-+——-+
| Variable_name | Value |
+———————-+——-+
| Max_used_connections | 107 |
+———————-+——-+
1 row in set (0.00 sec)

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To check active connections in mysql concurrent

SHOW STATUS WHERE `variable_name` = ‘Threads_connected’;

Mysql threads variable settings ideal

to list all connections

show status like ‘%onn%’;

mysql max connections recommended settings (how to choose)

In digital ocean manged sql limits

350 MB used Operating system.

750MB = 100MB per connection

4GB RAM Mysql dedicated machine 3.6GB usable and 3Gb*75=225

mysql max connections calculator

max_connections = (Available RAM – Global Buffers) / Thread Buffers

available ram =MySQL ram

Global buffers

SHOW VARIABLES LIKE ‘%buffer%’;

innodb_buffer_pool, key_buffer_size, query_cache_size, etc

Available RAM = Global Buffers + (Thread Buffers x max_connections)

max_connections = (Available RAM – Global Buffers) / Thread Buffers

global buffers

innodb_buffer_pool_size

innodb_log_buffer_size

innodb_additional_mem_pool

net_buffer_length

total size of global buffers

thread buffers

sort_buffer_size

myisam_sort_buffer_size

read_buffer_size

join_buffer_size

read_mid_buffer_size

total threaded buffer size

generally 10% global buffers 1gb vs 100Mb.

max connections 151 default.

Ram= 1000+ (100*151)

1000+15100

1010+(112*27)

3024+1010=4GB.

otherway

check previous max used connections

increase

check mysql error logs.

Update max connection limit in mysql.conf

my.cnf

max_connections = 500

mysql> SHOW VARIABLES LIKE “max_connections”;
+—————–+——-+
| Variable_name | Value |
+—————–+——-+
| max_connections | 151 |
+—————–+——-+
1 row in set (0.03 sec)

Check max used connections by mysql previous

maximum number of connections that have been in use simultaneously since the server started.

mysql> SHOW GLOBAL STATUS LIKE ‘max_use%’;
+—————————+———————+
| Variable_name | Value |
+—————————+———————+
| Max_used_connections | 26 |
| Max_used_connections_time | 2021-02-12 02:39:15 |
+—————————+———————+
2 rows in set (0.02 sec)

Variable_name | Value |
+————————+——-+
| max_connections | 151 |
| mysqlx_max_connections | 100 |
+————————+——-+

he maximum number of concurrent client connections X Plugin can accept. This is the X Plugin equivalent of max_connections;

mysql> SHOW GLOBAL VARIABLES LIKE ‘max_user_connections’;
+———————-+——-+
| Variable_name | Value |
+———————-+——-+
| max_user_connections | 0 |
+———————-+——-+
1 row in set (0.00 sec)

Aborted connection mysql

mysql> show global status like “%Aborted%”;
+————————+——-+
| Variable_name | Value |
+————————+——-+
| Aborted_clients | 0 |
| Aborted_connects | 47073 |
| Mysqlx_aborted_clients | 0 |
+————————+——-+
3 rows in set (0.00 sec)

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mysql> SHOW STATUS LIKE ‘Threads_connected’;
+——————-+——-+
| Variable_name | Value |
+——————-+——-+
| Threads_connected | 1 |
+——————-+——-+
1 row in set (0.00 sec)

also follow mysql memory allocation & optimization

Show threads currently running on MySQL DB instance

SHOW FULL PROCESSLIST\G

increasing thread_cache_size to allow more simultaneous users

max_used_connections is 151, and your current value for thread_cache_size is 10,

then you have a problem

thread_cache_size should be greater than Max_used_connections.

SHOW GLOBAL STATUS LIKE ‘Connections’;
SHOW GLOBAL STATUS LIKE ‘Threads_created’;
SHOW GLOBAL STATUS LIKE ‘Max_used_connections’;

Threads_created / Connections : If this is over 0.01, then increase

4/427=0.001

+—————+——-+
| Variable_name | Value |
+—————+——-+
| Connections | 427 |
+—————+——-+
1 row in set (0.01 sec)

mysql> SHOW GLOBAL STATUS LIKE ‘Threads_created’;
+—————–+——-+
| Variable_name | Value |
+—————–+——-+
| Threads_created | 4 |
+—————–+——-+
1 row in set (0.00 sec)

mysql> SHOW GLOBAL STATUS LIKE ‘Max_used_connections’;
+———————-+——-+
| Variable_name | Value |
+———————-+——-+
| Max_used_connections | 4 |
+———————-+——-+
1 row in set (0.00 sec)

default mysql thread cache size is = 9 or 10

max connecton limit 151

Max_used_connectionsprevipous restrt 47

so i set thread cache size to 50

show global variables like ‘innodb_buffer_pool_size’;

thread_cache_size | 9

set global thread_cache_size = 50;

mysql> set global thread_cache_size = 50;
Query OK, 0 rows affected (0.00 sec)

my.cnf

thread_cache_size = 50;

mysql too many connections fix

ERROR 1040(): Too many connections error in the MySQL error log.

when it appears you need to increase the mysql max connections per second. it needs extra memory like memory per connection. more at amz rds