From 01ec2e6cb6f20990e081dfe48fda3f445b8235a7 Mon Sep 17 00:00:00 2001 From: Anastasia Alexadrova Date: Fri, 7 Jun 2024 16:46:49 +0300 Subject: [PATCH 1/2] PBM-1333 Warning about breaking ACID during selective restore --- docs/features/selective-backup.md | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/docs/features/selective-backup.md b/docs/features/selective-backup.md index 160bd49d..ecab11ae 100644 --- a/docs/features/selective-backup.md +++ b/docs/features/selective-backup.md @@ -13,6 +13,11 @@ With the selective backup and restore functionality, you have the following opti 3. Restore certain databases and / or collections from a full backup 4. Make a point-in time recovery for the specified databases / collections. Available for replica sets only. +!!! warning + + Multi-collection transactions and time series collections are not supported. However, if you use them and try to make a selective restore, it may break ACID because not all operations with this transaction are restored. Thus, from the transaction's point of you, the data consistency may be broken. + + ## Sharded collections !!! admonition "Version added: [2.1.0](../release-notes/2.1.0.md)" From b2aec1e915b35bf77f7608dbdd9431ac064ee4b2 Mon Sep 17 00:00:00 2001 From: Anastasia Alexadrova Date: Thu, 13 Jun 2024 16:57:14 +0300 Subject: [PATCH 2/2] Updated the warning with an example --- docs/features/selective-backup.md | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/docs/features/selective-backup.md b/docs/features/selective-backup.md index ecab11ae..ab6e0995 100644 --- a/docs/features/selective-backup.md +++ b/docs/features/selective-backup.md @@ -15,7 +15,9 @@ With the selective backup and restore functionality, you have the following opti !!! warning - Multi-collection transactions and time series collections are not supported. However, if you use them and try to make a selective restore, it may break ACID because not all operations with this transaction are restored. Thus, from the transaction's point of you, the data consistency may be broken. + Multi-collection transactions are not supported. However, if you use them and attempt a selective restore, it may break [ACID](../reference/glossary.md#acid) because not all operations with this transaction are restored. PBM applies oplog events that relate only to the specified namespaces(s). Thus, from the transaction's point of view, the data consistency may be broken. + + For example, you have a transaction that involves collections A and B. When you restore collection A, PBM replays oplog events only for collection A and ignores those related to collection B. As a result, the state of collection B remains unchanged and is no longer consistent with collection A. ## Sharded collections