When I run a command to see our database variables:
show status like "%onn%"
I found that there are way too many connections for 2 people connecting to:
MariaDB [(none)]> show status like "%onn%";
+-----------------------------------------------+-------+
| Variable_name | Value |
+-----------------------------------------------+-------+
| Aborted_connects | 0 |
| Connection_errors_accept | 0 |
| Connection_errors_internal | 0 |
| Connection_errors_max_connections | 0 |
| Connection_errors_peer_address | 0 |
| Connection_errors_select | 0 |
| Connection_errors_tcpwrap | 0 |
| Connections | 56711 |
| Max_used_connections | 11 |
| Performance_schema_session_connect_attrs_lost | 0 |
| Slave_connections | 0 |
| Slaves_connected | 0 |
| Ssl_client_connects | 0 |
| Ssl_connect_renegotiates | 0 |
| Ssl_finished_connects | 0 |
| Threads_connected | 5 |
| wsrep_connected | ON |
+-----------------------------------------------+-------+
17 rows in set (0.00 sec)
The number of Connections doesn't go down. It keeps increasing.
CPU Utilization (Percent): 0.82%
KiB Mem : 4045012 total, 1625720 free, 718928 used
How can I diagnosis this issue to find the root cause?
It crashed and I suspect it could crash again.
UPDATED: According to this MySQL show status - active or total connections?, Threads_connected is the value I should look for open connections. Phew! Great!
However, my processlist could be very suspicious. Notice the Time column? Are they supposed to be that high?
MariaDB [(none)]> SHOW FULL processlist;
+------+---------------+-----------------+------------+---------+-------+-------------------------+-----------------------+----------+
| Id | User | Host | db | Command | Time | State | Info | Progress |
+------+---------------+-----------------+------------+---------+-------+-------------------------+-----------------------+----------+
| 1 | system user | | NULL | Sleep | 23321 | wsrep aborter idle | NULL | 0.000 |
| 2 | system user | | NULL | Sleep | 3955 | committed 3040010 | NULL | 0.000 |
| 5 | system user | | NULL | Daemon | NULL | | NULL | 0.000 |
| 6 | system user | | NULL | Daemon | NULL | | NULL | 0.000 |
| 3 | system user | | NULL | Daemon | NULL | | NULL | 0.000 |
| 4 | system user | | NULL | Daemon | NULL | | NULL | 0.000 |
| 7 | system user | | NULL | Daemon | NULL | InnoDB shutdown handler | NULL | 0.000 |
| 9 | system user | | NULL | Sleep | 3957 | committed 3040009 | NULL | 0.000 |
| 10 | system user | | NULL | Sleep | 3950 | committed 3040033 | NULL | 0.000 |
| 11 | system user | | NULL | Sleep | 3954 | committed 3040022 | NULL | 0.000 |
| 12 | system user | | NULL | Sleep | 3954 | committed 3040020 | NULL | 0.000 |
| 16 | system user | | NULL | Sleep | 3953 | committed 3040030 | NULL | 0.000 |
| 17 | system user | | NULL | Sleep | 3949 | committed 3040034 | NULL | 0.000 |
| 15 | system user | | NULL | Sleep | 3953 | committed 3040031 | NULL | 0.000 |
| 9670 | xxx | localhost:51574 | tabl_name | Sleep | 4 | | NULL | 0.000 |
| 9671 | xxx | localhost:51576 | NULL | Sleep | 53 | | NULL | 0.000 |
| 9939 | xxx | localhost | NULL | Sleep | 123 | | NULL | 0.000 |
| 9942 | xxx | localhost | NULL | Query | 0 | init | SHOW FULL processlist | 0.000 |
+------+---------------+-----------------+------------+---------+-------+-------------------------+-----------------------+----------+
18 rows in set (0.00 sec)
Unpanic. Connections is a counter. These are more interesting Connections / Uptime and Threads_running. Note that Max_used_connections is only 11. That's OK.
Please provide
* Ram size
* SHOW VARIABLES;
* SHOW GLOBAL STATUS; -- after it has been running at least a day
Do you have some form of "connection pooling"? Proxy server? MaxScale? HAProxy? Perhaps you are seeing "pooled" connections, not real ones.