SHOW STATUS;
FLUSH STATUS;
查看當前連接數 SHOW STATUS LIKE 'Thread_%';
Thread_cached:被緩存的線程的個數
Thread_running：處於激活狀態的線程的個數
Thread_connected：當前連接的線程的個數
Thread_created：總共被創建的線程的個數
Thread cache hits
Thread_connected = SHOW GLOBAL STATUS LIKE Thread_created;
Connections = SHOW GLOBAL STATUS LIKE 'Connections';
TCH=(1 - (Threads_created / Connections)) * 100
查看活動連接內容
SHOW PROCESSLIST;
如果 TCH數小於90%,創建連接耗費了時間,增大Thread_cached數量
QPS
Questions = SHOW GLOBAL STATUS LIKE 'Questions';
Uptime = SHOW GLOBAL STATUS LIKE 'Uptime';
QPS=Questions/Uptime
TPS
Com_commit = SHOW GLOBAL STATUS LIKE 'Com_commit';
Com_rollback = SHOW GLOBAL STATUS LIKE 'Com_rollback';
Uptime = SHOW GLOBAL STATUS LIKE 'Uptime';
TPS=(Com_commit + Com_rollback)/Uptime
QPS 和 TPS值一定要實時監控,如果接近架構搭建時的測試峰值,願上帝與你同在
Read/Writes Ratio
Qcache_hits = SHOW GLOBAL STATUS LIKE 'Qcache_hits';
Com_select = SHOW GLOBAL STATUS LIKE 'Com_select';
Com_insert = SHOW GLOBAL STATUS LIKE 'Com_insert';
Com_update = SHOW GLOBAL STATUS LIKE 'Com_update';
Com_delete = SHOW GLOBAL STATUS LIKE 'Com_delete';
Com_replace = SHOW GLOBAL STATUS LIKE 'Com_replace';
R/W=(Com_select + Qcache_hits) / (Com_insert + Com_update + Com_delete + Com_replace) * 100
讀寫比,優化數據庫的重要依據,讀的多就去優化讀,寫的多就去優化寫
Slow queries per minute
Slow_queries = SHOW GLOBAL STATUS LIKE 'Slow_queries';
Uptime = SHOW GLOBAL STATUS LIKE 'Uptime';
SQPM=Slow_queries / (Uptime/60)
Slow queries /Questions Ratio
Slow_queries = SHOW GLOBAL STATUS LIKE 'Slow_queries';
Questions = SHOW GLOBAL STATUS LIKE 'Questions';
S/Q=Slow_queries/Questions
新版本上線時要著重關注慢查詢,讓測試去踢開發者的屁股吧
Full_join per minute
Select_full_join = SHOW GLOBAL STATUS LIKE 'Select_full_join';
Uptime = SHOW GLOBAL STATUS LIKE 'Uptime';
FJPM=Select_full_join / (Uptime/60)
沒有使用索引而造成的full_join,優化索引去吧
Innodb buffer read hits
Innodb_buffer_pool_reads = SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_reads';
Innodb_buffer_pool_read_requests = SHOW GLOBAL STATUS LIKE 'Innodb_buffer_pool_read_requests';
IFRH=(1 - Innodb_buffer_pool_reads/Innodb_buffer_pool_read_requests) * 100
InnoDB Buffer命中率 目標 95%-99%;
Table Cache
Open_tables= SHOW GLOBAL STATUS LIKE 'Open_tables';
Opened_tables= SHOW GLOBAL STATUS LIKE 'Opened_tables';
table_cache= SHOW GLOBAL STATUS LIKE 'table_cache';
table_cache應該大於 Open_tables 小於 Opened_tables
作者“ylqmf的專欄”
