Shows the number of connection attempts, both successful and unsuccessful.
Connections status variable shows the number of connection attempts, both successful and unsuccessful.
Compute Thread Cache Miss Rate
Threads_createdstatus variable shows how many threads have been created since the server was brought online
Connectionsstatus variable shows how many new connection attempts have been made since the server was brought online
If you divide
Connections, that shows the thread cache miss rate:
SELECT threads_created, connections, (threads_created / connections) AS thread_cache_miss_rate FROM (SELECT gs1.VARIABLE_VALUE AS threads_created FROM information_schema.GLOBAL_STATUS gs1 WHERE gs1.VARIABLE_NAME LIKE 'Threads_created') tc JOIN (SELECT gs2.VARIABLE_VALUE AS connections FROM information_schema.GLOBAL_STATUS gs2 WHERE gs2.VARIABLE_NAME LIKE 'Connections') c;
If the above query is executed at different times, the results can be interpreted in the following way:
thread_cache_miss_ratestays constant or grows and approaches
1, the current thread cache size is not large enough to keep up with new connection requests.
thread_cache_miss_rateshrinks and approaches
0, the current thread cache size is either equal to or larger than needed to keep up with new connection requests. To determine whether it is larger than needed, the
Threads_cachedstatus variable can also be monitored to determine whether the thread cache consistently contains too many cached threads.
For information about how to configure the thread cache, see "thread_
Show Value with
SHOW GLOBAL STATUS statement can show the global value:
SHOW GLOBAL STATUS LIKE 'Connections';
Since this status variable is only global scope,
SHOW STATUS and
SHOW SESSION STATUS also show the global value.
information_schema.GLOBAL_STATUS table can be queried to obtain the global value:
SELECT * FROM information_schema.GLOBAL_STATUS WHERE VARIABLE_NAME LIKE 'Connections';
This status variable is only global scope, so the
information_schema.SESSION_STATUS table can also be queried to obtain the global value:
SELECT * FROM information_schema.SESSION_STATUS WHERE VARIABLE_NAME LIKE 'Connections';