show status;
flush status;
檢視當前連線數 show status like 'thread_%';
thread_cached:被快取的執行緒的個數
thread_running：處於啟用狀態的執行緒的個數
thread_connected：當前連線的執行緒的個數
thread_created：總共被建立的執行緒的個數
thread cache hits
thread_connected = show global status like thread_created;
connections = show global status like 'connections';
tch=(1 - (threads_created / connections)) * 100
檢視活動連線內容
show processlist;
如果 tch數小於90%,建立連線耗費了時間,增大thread_cached數量
qpsquestions = show global status like 'questions';
uptime = show global status like 'uptime';
qps=questions/uptime
tpscom_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,優化資料庫的重要依據,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
temp tables to disk ratio
created_tmp_tables = show global status like 'created_tmp_tables';
created_tmp_disk_tables = show global status like 'created_tmp_disk_tables';
tdr=(created_tmp_disk_tables/created_tmp_tables)*100
show global status like 'innodb_row_lock_%';
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