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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.

Has QUIT--Anony-Mousse
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HarsH
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  • There should be some `DataDir` directives in your my.ini/my.cnf whichn specify where the cluster files are stored. – Marc B Jan 28 '11 at 15:07

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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.

ircmaxell
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