[ZOOKEEPER-1879] improve the correctness checking of txn log replay

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Affects Version/s: 3.4.6, 3.5.0
• Component/s: server
• Assignee: Unassigned
• Reporter: Patrick D. Hunt
• Created: 10/Feb/14 20:46
• Updated: 03/Feb/22 08:50

Description

In ZOOKEEPER-1573 we decided to fix an issue by relaxing some of the checking. Specifically when the sequence of txns is as follows:

• zxid 1: create /prefix/a
• zxid 2: create /prefix/a/b
• zxid 3: delete /prefix/a/b
• zxid 4: delete /prefix/a

the log may fail to replay.

We addressed this by relaxing a check, which is essentially invalid for this case, but is important in finding corruptions of the datastore.

We should add this check back with proper validation of correctness.

Issue Links

• is related to: ZOOKEEPER-1573 Unable to load database due to missing parent node