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mysqlcluster-computingdatabase-cluster

Where exactly the table-data stored using MySQL-cluster gets stored?

I am a new-bee to MySQL cluster and wanted to know where exactly the data is stored in MySQL-cluster and where can i see it without directly. As we can see the separate files for each tables in MySQL 5.x databases. I have to verify for the same in Cluster formation. Please reply.

Solution

  • Well, MySQL-Cluster is just NDB (Network DataBase). Now, the NDB engine has a 2 main storage mechanisms.

    1. In memory. This has been available since NDB was introduced. Basically, it's just a series of memory tables that store the data. If all of your node sets go down, you lose all of your data. So you'll need to either replicate to a hard storage, or backup often and replay binary logs in the case of a server reboot.

    2. Since MySQL 5.1.6, NDB supports disk backed storage. That means that the working set is still kept in memory, but all writes are flushed to a disk buffer. So a restart just re-reads the disk. See MySQl Cluster Disk Data Types.

      Another useful read is this whitepaper (PDF) about recovery principles.