tuning-primer.sh 參數詳解

使用tuning-primer.sh 能夠自動檢測mysql的性能和一些建議，

列舉一些參數意義
腳本支持my.cnf文件，能夠把user, password, host, socket等鏈接參數放在~/.my.cnf文件裏，若是使用了自定義的socket文件，請修改tuning-primer.sh文件中關於socket文件位置的變量。

運行 tuning-primer.sh顯示說明

SLOW QUERIES	慢查詢檢查
SLOW QUERIESThe slow query log is enabled.	說明我已經啓用了慢查詢記錄功能。也就是參數 slow_query_log = 1
Current long_query_time = 5.000000 sec.	慢查詢的閥值時間。也就是參數 long_query_time = 5
You have 17 out of 638844 that take longer than 5.000000 sec. to complete	說明慢查詢日誌中記錄了17條查詢時間超過5秒的語句。 slow_query_log_file=/data/ats_db/mysql-slow.log設置慢查詢日誌路徑。使用 mysqldumpslow命令查詢慢日誌
Your long_query_time seems to be fine	慢查詢閥值時間設置得在推薦的範圍內
BINARY UPDATE LOG	更新二進制日誌文件
The binary update log is enabled	這項說明啓用了bin-log日誌功能。參數 log-bin = /data/ats_db/mysql-bin
Binlog sync is not enabled, you could loose binlog records during a server crash	沒有啓用 sync_binlog 選項。也便是將二進制日誌實時寫入到磁盤經過 sync_binlog=1來指定
WORKER THREADS	工做線程
Current thread_cache_size = 8	當前線程緩存大小。 thread_concurrency = 8
Current threads_cached = 7	Show status like ‘threads_cached’
Current threads_per_sec = 0	腳本先執行Show status like ‘Threads_cached’查看當前的線程建立狀況，而後sleep 1後在執行相同的命令，最終後者減去前者的數就是每秒線程建立數。
Historic threads_per_sec = 0	該值是使用Threads_cached /uptime得到的。
Your thread_cache_size is fine
MAX CONNECTIONS	最大鏈接數
Current max_connections = 1024	當前配置文件中設置的併發鏈接數
Current threads_connected = 2	當前線程鏈接誒數。 show status like ‘Threads_connected’
Historic max_used_connections = 4	show status like ‘Max_used_connections’;
The number of used connections is 0% of the configured maximum.	這個值使用 Max_used_connections*100/ max_connections得出。
You are using less than 10% of your configured max_connections. Lowering max_connections could help to avoid an over-allocation of memory See 「MEMORY USAGE」 section to make sure you are not over-allocating	Max_used_connections的值不足max_connections值的10%。設置合適的max_connections值有助於節省內存。
MEMORY USAGE	內存使用
Max Memory Ever Allocated : 841 M	Max Memory Ever Allocated = max_memory
Configured Max Per-thread Buffers : 28.40 G	Configured Max Per-thread Buffers = per_thread_buffers
Configured Max Global Buffers : 586 M	Configured Max Global Buffers = per_thread_max_buffers
Configured Max Memory Limit : 28.97 G	Configured Max Memory Limit = total_memory 這 一項很重要，他是將各個緩存的大小累加，而後同max_connections相乘，從而得出當達到max_connections後須要分配的內存有多 少。我這裏因爲max_connections寫得很大，形成了最大內存限制超過了真實內存不少，因此建議不要隨意增大max_connections的 值。減少 max_connections的值，最終保證最大內存限制在真實內存的90%如下。
Physical Memory : 7.79 G	實際物理內存
Max memory limit exceeds 90% of physical memory
per_thread_buffers (read_buffer_size+read_rnd_buffer_size +sort_buffer_size+thread_stack+ join_buffer_size+binlog_cache_size)*max_connectionsper_thread_max_buffers (read_buffer_size+read_rnd_buffer_size +sort_buffer_size+thread_stack +join_buffer_size+binlog_cache_size)*max_used_connections global_buffers innodb_buffer_pool_size+innodb_additional_mem_pool_size+innodb_log_buffer_size+ key_buffer_size+query_cache_size max_memory=global_buffers+per_thread_max_buffers total_memory=global_buffers+per_thread_buffers
KEY BUFFER	Key 緩衝
Current MyISAM index space = 222 K	當前數據庫MyISAM表中索引佔用磁盤空間
Current key_buffer_size = 512 M	MySQL配置文件中key_buffer_size 設置的大小
Key cache miss rate is 1 : 3316	Key_read_requests/ Key_reads 這裏說明3316次讀取請求中有1次丟失(也就是說1次讀取磁盤)
Key buffer free ratio = 81 %	key_blocks_unused * key_cache_block_size / key_buffer_size * 100
Your key_buffer_size seems to be fine
QUERY CACHE	Query 緩存
Query cache is enabled	該項說明 咱們指定了query_cache_size 的值。若是query_cache_size=0的話這裏給出的提示是： Query cache is supported but not enabled Perhaps you should set the query_cache_size
Current query_cache_size = 64 M	當前系統query_cache_size 值大小 [F]
Current query_cache_used = 1 M	query_cache_used =query_cache_size-qcache_free_memory
Current query_cache_limit = 128 M	變量 query_cache_limit 大小
Current Query cache Memory fill ratio = 1.79 %	query_cache_used/query_cache_size *100%
Current query_cache_min_res_unit = 4 K	show variables like ‘query_cache_min_res_unit’;
Your query_cache_size seems to be too high. Perhaps you can use these resources elsewhere	這項給出的結論是query_cache_size的值設置的有些太高。其比對標準是 「Query cache Memory fill ratio」的值若是小於<25%就會給出這個提示。能夠將這些資源應用到其餘的地方
MySQL won’t cache query results that are larger than query_cache_limit in size	MySQL不會將大於query_cache_limit的查詢結果進行緩存
show status like ‘Qcache%’;Qcache_free_blocks        10 Qcache_free_memory        65891984 Qcache_hits            14437 Qcache_inserts            707 Qcache_lowmem_prunes    0 Qcache_not_cached        216 Qcache_queries_in_cache    540 Qcache_total_blocks        1191
SORT OPERATIONS	SORT 選項
Current sort_buffer_size = 6 M	show variables like ’sort_buffer%’;
Current read_rnd_buffer_size = 16 M	show variables like ‘read_rnd_buffer_size%’;
Sort buffer seems to be fine
JOINS	JOINS
Current join_buffer_size = 132.00 K	show variables like ‘join_buffer_size%’;join_buffer_size= join_buffer_size+4kb
You have had 6 queries where a join could not use an index properly	這裏的6是經過 show status like ‘Select_full_join’; 得到的
You should enable 「log-queries-not-using-indexes」 Then look for non indexed joins in the slow query log. If you are unable to optimize your queries you may want to increase your join_buffer_size to accommodate larger joins in one pass.Note! This script will still suggest raising the join_buffer_size when ANY joins not using indexes are found.	你須要啓用 「log-queries-not-using-indexes」 而後在慢查詢日誌中看是否有取消索引的joins語句。若是不優化查詢語句的話，則須要增大join_buffer_size。
OPEN FILES LIMIT	文件打開數限制
Current open_files_limit = 1234 files	show variables like ‘open_files_limit%’;
The open_files_limit should typically be set to at least 2x-3xthat of table_cache if you have heavy MyISAM usage.	若是系統中有不少的MyISAM類型的表，則建議將open_files_limit 設置爲2X~3X的table_open_cache show status like ‘Open_files’;open_files_ratio= open_files*100/open_files_limit 若是open_files_ratio 超過75% 則須要加大open_files_limit
Your open_files_limit value seems to be fine
TABLE CACHE	TABLE 緩存
Current table_open_cache = 512 tables	show variables like ‘table_open_cache’;
Current table_definition_cache = 256 tables	show variables like ‘ table_definition_cache ‘;
You have a total of 368 tables	SELECTCOUNT(*) FROM INFORMATION_SCHEMA.TABLES WHERE TABLE_TYPE=’BASE TABLE’
You have 371 open tables.	show status like ‘Open_tables’;
The table_cache value seems to be fine	Open_tables /table_open_cache*100% < 95%
You should probably increase your table_definition_cache value.	table_cache_hit_rate =open_tables*100/opened_tables
TEMP TABLES	臨時表
Current max_heap_table_size = 16 M	show variables like ‘max_heap_table_size’;
Current tmp_table_size = 16 M	show variables like ‘tmp_table_size’;
Of 285 temp tables, 11% were created on disk	Created_tmp_tables=285created_tmp_disk_tables*100/ (created_tmp_tables+created_tmp_disk_tables)=11%
Created disk tmp tables ratio seems fine
TABLE SCANS	掃描表
Current read_buffer_size = 6 M	show variables like ‘read_buffer_size’;
Current table scan ratio = 9 : 1	read_rnd_next =show global status like ‘Handler_read_rnd_next’; com_select= show global status like ‘Com_select’; full_table_scans=read_rnd_next/com_select Current table scan ratio = full_table_scans : 1″ 若是表掃描率超過4000，說明進行了太多表掃描，頗有可能索引沒有建好，增長read_buffer_size值會有一些好處，但最好不要超過8MB。
read_buffer_size seems to be fine
TABLE LOCKING	TABLE LOCKING
Current Lock Wait ratio = 0 : 5617	show global status like’Table_locks_waited’; show global status like ‘Questions’; 若是 Table_locks_waited=0 Current Lock Wait ratio = 0: Questions
Your table locking seems to be fine