Книга: Mysql: Mysql Cluster, Innodb, Myisam, Drizzle, Adminer, Mysql Archive, Falcon, Ndb Cluster, Mysql Federated, Maria, Xtradb, Mysql Enterprise

Purchase includes free access to book updates online and a free trial membership in the publisher's book club where you can select from more than a million books without charge. Excerpt: MySQL Cluster is a technology which provides shared-nothing clustering capabilities for the MySQL database management system. It was first included in the production release of MySQL 4.1 in November 2004. It is designed to provide high availability and high performance, while allowing for nearly linear scalability. MySQL Cluster is implemented through an additional storage engine available within MySQL called NDB or NDBCLUSTER ('NDB' stands for Network Database). MySQL Cluster has a few important concepts behind its design, which give both benefits and disadvantages. MySQL Cluster uses synchronous replication through a two-phase commit mechanism in order to guarantee that data is written to multiple nodes upon committing the data. (This is in contrast to what is usually referred to as 'MySQL Replication', which is asynchronous.) Two copies (known as replicas) of the data are required to guarantee availability however, the cluster can be configured to store between one and four copies at any single time. Starting with MySQL 5.1, it is also possible to replicate asynchronously between clusters this is sometimes referred to as 'MySQL Cluster Replication' or 'geographical replication'. See MySQL Cluster Replication. Data within NDB tables is automatically partitioned across all of the data nodes in the system. This is done based on a hashing algorithm based on the PRIMARY KEY on the table, and is transparent to the end application. In the 5.1 release, users can define their own partitioning schemes. MySQL Cluster allows datasets larger than the capacity of a single machine to be stored and accessed across multiple machines. MySQL Cluster maintains all indexed columns in distributed memory. Non indexed columns can also be maintained in distribu... More: booksllc.net/?id=1202462