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new 293c27bed [doc] Document detail abouth the snapshot expiration (#1506)
293c27bed is described below
commit 293c27bed9fd3be967486c00106a5a2202b4ca82
Author: Congxian Qiu <[email protected]>
AuthorDate: Thu Jul 6 11:18:33 2023 +0800
[doc] Document detail abouth the snapshot expiration (#1506)
---
docs/content/maintenance/manage-snapshots.md | 126 +++++++++++++++++++++++++++
1 file changed, 126 insertions(+)
diff --git a/docs/content/maintenance/manage-snapshots.md
b/docs/content/maintenance/manage-snapshots.md
index a73d84115..56008bc90 100644
--- a/docs/content/maintenance/manage-snapshots.md
+++ b/docs/content/maintenance/manage-snapshots.md
@@ -71,6 +71,132 @@ Snapshot expiration is controlled by the following table
properties.
</tbody>
</table>
+When the number of snapshots is less than `snapshot.num-retained.min`, no
snapshots will be expired(even the condition `snapshot.time-retained` meet),
after which `snapshot.num-retained.max` and `snapshot.time-retained` will be
used to control the snapshot expiration until the remaining snapshot meets the
condition.
+
+The following example show more details(`snapshot.num-retained.min` is 2,
`snapshot.time-retained` is 1h, `snapshot.num-retained.max` is 5):
+
+> snapshot item is described using tuple (snapshotId, corresponding time)
+
+<table>
+<thead>
+ <tr>
+ <th class="text-left" style="width: 30%">New Snapshots</th>
+ <th class="text-left" style="width: 40%">All snapshots after expiration
check</th>
+ <th class="text-left" style="width: 30%">explanation</th>
+ </tr>
+ </thead>
+ <tbody>
+ <tr>
+ <td>
+ (snapshots-1, 2023-07-06 10:00)
+ </td>
+ <td>
+ (snapshots-1, 2023-07-06 10:00)
+ </td>
+ <td>
+ No snapshot expired
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-2, 2023-07-06 10:20)
+ </td>
+ <td>
+ (snapshots-1, 2023-07-06 10:00) <br>
+ (snapshots-2, 2023-07-06 10:20)
+ </td>
+ <td>
+ No snapshot expired
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-3, 2023-07-06 10:40)
+ </td>
+ <td>
+ (snapshots-1, 2023-07-06 10:00) <br>
+ (snapshots-2, 2023-07-06 10:20) <br>
+ (snapshots-3, 2023-07-06 10:40)
+ </td>
+ <td>
+ No snapshot expired
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-4, 2023-07-06 11:00)
+ </td>
+ <td>
+ (snapshots-1, 2023-07-06 10:00) <br>
+ (snapshots-2, 2023-07-06 10:20) <br>
+ (snapshots-3, 2023-07-06 10:40) <br>
+ (snapshots-4, 2023-07-06 11:00) <br>
+ </td>
+ <td>
+ No snapshot expired
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-5, 2023-07-06 11:20)
+ </td>
+ <td>
+ (snapshots-2, 2023-07-06 10:20) <br>
+ (snapshots-3, 2023-07-06 10:40) <br>
+ (snapshots-4, 2023-07-06 11:00) <br>
+ (snapshots-5, 2023-07-06 11:20)
+ </td>
+ <td>
+ snapshot-1 was expired because the condition
`snapshot.time-retained` is not met
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-6, 2023-07-06 11:30)
+ </td>
+ <td>
+ (snapshots-3, 2023-07-06 10:40) <br>
+ (snapshots-4, 2023-07-06 11:00) <br>
+ (snapshots-5, 2023-07-06 11:20) <br>
+ (snapshots-6, 2023-07-06 11:30)
+ </td>
+ <td>
+ snapshot-2 was expired because the condition `snapshot.time-retained`
is not met
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-7, 2023-07-06 11:35)
+ </td>
+ <td>
+ (snapshots-3, 2023-07-06 10:40) <br>
+ (snapshots-4, 2023-07-06 11:00) <br>
+ (snapshots-5, 2023-07-06 11:20) <br>
+ (snapshots-6, 2023-07-06 11:30) <br>
+ (snapshots-7, 2023-07-06 11:35)
+ </td>
+ <td>
+ No snapshot expired
+ </td>
+ </tr>
+ <tr>
+ <td>
+ (snapshots-8, 2023-07-06 11:36)
+ </td>
+ <td>
+ (snapshots-4, 2023-07-06 11:00) <br>
+ (snapshots-5, 2023-07-06 11:20) <br>
+ (snapshots-6, 2023-07-06 11:30) <br>
+ (snapshots-7, 2023-07-06 11:35) <br>
+ (snapshots-8, 2023-07-06 11:36)
+ </td>
+ <td>
+ snapshot-3 was expired because the condition
`snapshot.num-retained.max` is not met
+ </td>
+ </tr>
+ </tbody>
+</table>
+
Please note that too short retain time or too small retain number may result
in:
- Batch queries cannot find the file. For example, the table is relatively
large and
