mirror of https://gitee.com/bigwinds/arangodb
48 lines
2.1 KiB
Markdown
48 lines
2.1 KiB
Markdown
<!-- don't edit here, its from https://@github.com/arangodb/arangosync.git / docs/Manual/ -->
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# Introduction
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At some point in the grows of a database, there comes a need for replicating it
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across multiple datacenters.
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Reasons for that can be:
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- Fallback in case of a disaster in one datacenter
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- Regional availability
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- Separation of concerns
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And many more.
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Starting from version 3.3, ArangoDB supports _datacenter to datacenter
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replication_, via the _ArangoSync_ tool.
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ArangoDB's _datacenter to datacenter replication_ is a solution that enables you
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to asynchronously replicate the entire structure and content in an ArangoDB Cluster
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in one place to a Cluster in another place. Typically it is used from one datacenter
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to another.
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<br/>It is not a solution for replicating single server instances.
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The replication done by _ArangoSync_ in **asynchronous**. That means that when
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a client is writing data into the source datacenter, it will consider the
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request finished before the data has been replicated to the other datacenter.
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The time needed to completely replicate changes to the other datacenter is
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typically in the order of seconds, but this can vary significantly depending on
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load, network & computer capacity.
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_ArangoSync_ performs replication in a **single direction** only. That means that
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you can replicate data from cluster _A_ to cluster _B_ or from cluster _B_ to
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cluster _A_, but never at the same time.
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<br/>Data modified in the destination cluster **will be lost!**
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Replication is a completely **autonomous** process. Once it is configured it is
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designed to run 24/7 without frequent manual intervention.
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<br/>This does not mean that it requires no maintenance or attention at all.
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<br/>As with any distributed system some attention is needed to monitor its operation
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and keep it secure (e.g. certificate & password rotation).
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Once configured, _ArangoSync_ will replicate both **structure and data** of an
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**entire cluster**. This means that there is no need to make additional configuration
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changes when adding/removing databases or collections.
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<br/>Also meta data such as users, foxx application & jobs are automatically replicated.
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