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docs: document bookmarking + remove warning about replication lag

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refs #34
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Christian Schwarz
2017-12-28 13:24:25 +01:00
parent 03ba2bb7c8
commit 9a19615fd4
2 changed files with 14 additions and 9 deletions
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docs/configuration/prune.rst
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@@ -53,12 +53,11 @@ The following procedure happens during pruning:
.. ATTENTION::
.. TODO this is obsolete as soon as bookmarks are created during snapshotting
The configuration of the first interval (``1x1h(keep=all)`` in the example) determines the **maximum allowable replication lag** because the source and destination pruning policies do not coordinate:
if replication does not work for whatever reason, source will continue to execute the prune policy.
Eventually, source destroys a snapshot that has never been replicated to destination, degrading the temporal resolution of your backup.
The configuration of the first interval (``1x1h(keep=all)`` in the example) determines the **maximum allowable replication lag** between source and destination.
After the first interval, source and destination likely have different retention settings.
This means source and destination may prune different snapshots, prohibiting incremental replication froms snapshots that are not in the first interval.
Thus, **always** configure the first interval to ``1x?(keep=all)``, substituting ``?`` with the maximum time replication may fail due to downtimes, maintenance, connectivity issues, etc.
**Always** configure the first interval to ``1x?(keep=all)``, substituting ``?`` with the maximum time replication may fail due to downtimes, maintenance, connectivity issues, etc.
After outages longer than ``?`` you may be required to perform **full replication** again.
.. We intentionally do not mention that bookmarks are used to bridge the gap between source and dest that are out of sync snapshot-wise. This is an implementation detail.