Mysql集群方案(一) - Cluster & Replication 介绍

对数据库集群处于初步学习阶段,记录备忘
扫盲:
提到Mysql集群(Mysql Cluster),其实有两类方案, 名字上的Mysql Cluster只是其中一类.
Mysql Cluster 将数据放内存中
A MySQL Cluster consists of a set of computers, each running a one or more processes which may include a MySQL server, a data node, a management server, and (possibly) a specialized data access programs. The relationship of these components in a cluster is shown here:



如上图，这个系统中，最小的集群可能是如此：

Node	IP Address
Management (MGM) node	192.168.0.10
MySQL server (SQL) node	192.168.0.20
Data (NDBD) node "A"	192.168.0.30
Data (NDBD) node "B"	192.168.0.40

topology



Replication - Read/Write



Replication - Separate Read & Write
Using replication to improve the performance during scaleout



Comparison

Requirements	MySQL Replication	MySQL Replication + Heartbeat	MySQL Heartbeat + DRBD	MySQL Cluster
Availability
Automated IP failover	No	Yes	Yes	No
Automated database failover	No	No	Yes	Yes
Typical failover time	User/script-dependent	Varies	< 30 seconds	< 3 seconds
Automatic resynchronization of data	No	No	Yes	Yes
Geographic redundancy support	Yes	Yes	Yes, when combined with MySQL Replication	Yes, when combined with MySQL Replication
Scalability
Built-in load balancing	No	No	No	Yes
Supports Read-intensive applications	Yes	Yes	Yes, when combined with MySQL Replication	Yes
Supports Write-intensive applications	No	No	Yes	Yes
Maximum number of nodes per group	One master, multiple slaves	One master, multiple slaves	One active (primary), one passive (secondary) node	255
Maximum number of slaves	Unlimited (reads only)	Unlimited (reads only)	One (failover only)	Unlimited (reads only)

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