Database week 14

Comp 305-001/488-305: Database Administration

Spring 2016: Tuesdays, 4:15-6:45, Corboy L08

Week 14

Review conflict-serializability test

Locks

NoSQL databases and CAP
start with sharding

MySQL Cluster

This is composed of the following:

One management node
One or more mysqld node
Multiple data nodes

The straightforward way to use MySQL cluster is to use the mysqld node as an SQL interface to the data, just like using MySQL itself. However, it is also possible to access the data directly, using other APIs; this is where MySQL Cluster becomes a "NoSQL" (here pretty definitively Not only SQL) environment.

The data nodes can be used for

"sharded" data: different subsets of the data, partitioned by key range, are kept on different nodes
replicated data
load balancing

MySQL Cluster does transparent auto-sharding; the DBA can supposedly remain unaware of it.

The mysqld node is just one of many possible "application layers" used to access the data nodes. It uses the NDB/NDB-Cluster storage engine, which is somewhat different from InnoDB.

Other APIs include:

Native NDB library in C++
ClusterJ/JNI
Javascript/Node.JS
Apache/mod_ndb (for interfacing with Apache web servers)
memcached/ndb_eng