Clarify backup/restore strategy regarding system db #2521
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NataliaIvakina
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This PR includes documentation updates Updated pages: |
| See xref:clustering/monitoring/show-databases-monitoring.adoc#show-databases-monitoring-listing-single[Listing a single database] for more information. | ||
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| However, _restoring_ a database in a cluster is different since it is not known in advance how a database is going to be allocated to the servers in a cluster. | ||
| This method relies on the seed already existing on one of the servers. |
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I feel like it's not totally clear what 'this method' refers to, and I'm a little confused by the 'existing on one of the servers' now I look at it.
Perhaps something like:
Restoring from the command line involves putting a copy of the database on disk on each server that will need it.
That can be awkward to achieve.
| When backing up a clustered database, be aware that the xref:clustering/introduction.adoc#clustering-introduction-operational[cluster topology] metadata is not included in the backup. | ||
| The cluster topology is stored in the `system` database and describes how the copies of a database should be spread across the servers in a cluster. | ||
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| Because this metadata is excluded from backups, restoring to a new cluster environment requires manual reconfiguration of servers modes and database allocations. |
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This seems a bit negative about the topology not being backed up. I think it's actually a positive. Perhaps something more along the lines of:
Backing up a database only includes the database contents, and the RBAC associated with the database if you include the metadata.
This means you specify the desired topology when you restore the backup, allowing you to restore with a different topology than was present when backed up.
The database will be allocated to servers that are present at restore time to fulfil that topology.
I wouldn't mention that the topology is stored in system, that's effectively an implementation detail.
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Good point! Be positive 🙂 You're right, I'll rewrite it.
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