MySQL運維&開發規範

阿新 • • 發佈：2019-01-16

MySQL運維&開發規範

約定

MySQL, 通用稱謂，泛指MySQL這個服務軟體等相關代號
mysql, 沒有上下文語義時，等同上面的含義
mysqld, MySQL服務軟體的服務端程式、程序檔案
mysql,有上下文時，通常指MySQL服務軟體中的客戶端工具
同上，也包括 mysqladmin/mysqldump/mysqlbinlog等其他工具
不正確寫法
- Mysql
- MySql
- MYSQL
- mYSQL …

MySQL發展史

MySQL是全球最流行的開源關係型資料庫，開源資料庫界佔有率第二
伴隨著網際網路的發展而成長
網際網路業務標配，好基友LA(N)MP組合

WEB2. 0時代後更是突飛猛進

歷史

1999-2003年，3.23
2002-2007年，4.0
2003-2009年，4.1
2004 - 2012年，5.0
2006-2014年，5.1
2010-2015年，5.5
2011 年，5.6
2013年，5.7
2016年，8.0

主流分支

ORACLE MySQL
- 官方正統
Percona Server
- 基於InrnoDB增加提升效能及易管理性補丁後，形成XtraDB引擎
- 工具：XtraBackup、pt-toolkit系列
- 和官方保持一致，基本相容
MariaDB
- MySQL創始人Monty建立，目標在於替換現有的MySQL，也包含了Percona 的XtraDB、TokuDB在內的多種實用引擎
- 非主流分支，和官方版木區別越來越大，有很多不相容

Percona特色

取代企業版特有功能
- PAM Authentication
- Thread pool/執行緒池
- Audit/審計
其他
- 整合 TokuDB
- Extra Diagnostic Features
- Performance & Scalability Enhancements
- Extra Features for DBA/Operations Staff

MariaDB支援的引擎

ColumnStore, a column oriented storage engine optimized for Data warehousing.

MyRocks, a storage engine with great compression, in 10.2
Aria, My ISAM replacement with better caching.
FederatedX (drop-in replacement for Federated)
OQGRAPH (In MariaDB 5.2 and later. Disabled in MariaDB 5.5 only.) — new in 5.2
SphinxSE — new in 5.2
TokuDB in MariaDB 5.5 and later.
CONNECT in MariaDB 10.0 and later.
SEQUENCE in MariaDB 10.0 and later.
Spider in MariaDB 10.0 and later.
Cassandra in MariaDB 10.0

MariaDB效能提升

A lot of optimizer enhancements，子查詢&JOIN優化
windows系統下的 InnoDB AIO優化
checksum table效率更高
字符集轉換效率更高
更早實現了並行複製、多源複製、執行緒池、JSON、虛擬列
比MySQL 5.7更早實現了客戶端連線效率提升

執行緒池作用

應對瞬間的高併發的短連線的場景，在MySQL 5.7 之前，處理高併發短連線請求，MySQL 效率較低。即瞬間大量的連線請求進來，會造成執行緒大量的上下文切換，導致CPU較高，執行緒池的功能可有效緩解這樣的問題，先將所有的請求放在一個佇列中，再從執行緒池的佇列中拿出一個執行緒去處理，避免大量的上下文切換

MariaDB新特性

Microseconds in MariaDB 一 new in 5.3
Number of supported decimals in DECIMAL has increased from 30 to 38.— new in 10.2
Microsecond Precision in Processlist
Table Elimination
Virtual Columns — new in 5.2
CHECK CONSTRAINT — new in 10.2
DEFAULT expression, including DEFAULT for BLOB and TEXT. — new in 10.2
Extended User Statistics -new in 5.2
KILL all queries for a user -new in 5.3
KILL QUERY ID - terminates the query by query_id, leaving the connection intact — new in 10.0.5,
Pluggable Authentication — new in 5.2
Storage-engine-specific CREATE TABLE — new in 5.2
Enhancements to INFORMATION SCHEMA.PLUGINS table — new in 5.2
Group commit for the binary log. This makes replication notably faster! — new in 5.3
Added -rewrite-db mysqlbinlog option to change the used database — new in 5.2
Progress reporting for ALTER TABLE and LOAD DATA INFILE. — new in 5.3
Faster joins and subqueries. — new in 5.3
HandlerSocket and faster HANDLER calls. — new in 5.3
Dynamic Columns support. — new in 5.3
GIS Functionality - new in 5.3
Multi-source replication. — new in 10.0
Global Transaction ID. - new in 10.0
和官方GTID並不相容，與官方版本只能搭建基於檔案的複製
SHOW EXPLAIN gives the EXPLAIN plan for a query running in another thread. 一 new in 10.0
Roles.——new in 10.0
PCRE Regular Expressions (including REGEXP_REPLACE〇). 一 new in 10.0
DELETE … RETURNING. — new in 10.0
See also a detailed breakdown of System variable differences between MariaDB 5.5 and MySQL 5.5 and System variable differences between MariaDB 10.0 and MySQL 5.6.

MariaDB 相容性

Incompatibilities between MariaDB 10.0 and MySQL 5.6
- MariaDB GTID is not compatible with MySQL 5.6
- MariaDB 10.0 multi-source replication, not MySQL 5.6
- MariaDB 10.0 dynamic columns, not MySQL 5.6
- CREATE TABLE … SELECT在 slave 上改造成CREATE OR REPLACE TABLE
- can not support the MySQL Memcached plugin
- not Users created with MySQL’s SHA256 password algorithm
- does not support delayed replication
- MariaDB 10.1 does not support MySQL 5.7’s JSON.
- MariaDB 10.1’s InnoDB encryption is implemented differently than MySQL 5.7’s InnoDB encryption.
- MariaDB 10.1 does not support the ngram and MeCab full-text parser plugins - MDEV-10267, MDEV-10268.
- MariaDB 10.1 does not support multiple triggers for a table-MDEV-6112.
- Note: Multiple triggers per table was added in 10.2
- MariaDB stores JSON as true text, not in binary format as MySQL. The reason is that our JSON functions are much faster than MySQL’s so we didn’t need to see a need for storing things in binary format as it adds a lot of complexity when manipulating JSON objects.
- MariaDB 10.2 does not support the ngram and MeCab full-text parser plugins - MDEV-10267, MDEV-10268.
- MariaDB 10.2 does not support the MySQL X plugin.
- MariaDB 10.2 does not support the MySQL general table spaces.

關於MySQL DBA

運維DBA
- 日常管理，備份、恢復、故障處理、高可用保障等
- 整體優化，伺服器、網路、MySQL、架構
開發DBA
- 深入理解業務需求
- SQL優化，編寫儲存過程、觸發器等業務SQL程式碼
DB架構師
- 整體架構設計、優化

MySQL運維&開發規範