There are several situations in which you may find yourself restoring a backup. In this recipe, we will briefly discuss common causes for recovery and then show an example of using the ndb_restore
for a painless backup recovery. Later in the recipe, we will discuss techniques to ensure that data is not changed during a restore. In broader terms, a backup recovery is required when the running cluster is, for whatever reason, no longer running and the automatically created checkpoints stored in the DataDir
on each storage node are not sufficient for recovery. Some examples that you may encounter are as follows:
A disk corruption has occurred which destroyed your
DataDir
on all storage nodes in anodegroup
and simultaneously crashed the machines so the in-memory copy of data was lost.You are conducting a major cluster upgrade (which requires a backup, total shutdown, start of the new cluster, and a restore). In this case, be aware that you can generally...