[IGNITE-18502] Excessive full partition scan on node start

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Duplicate
• Labels: ignite-3
• Ignite Flags: Docs Required, Release Notes Required
• Assignee: Unassigned
• Reporter: Vladislav Pyatkov
• Created: 05/Jan/23 11:03
• Updated: 13/Feb/24 15:50
• Resolved: 13/Feb/24 15:50

Description

Motivation
All tables have a transactional nature, even if we don't use transactions explicitly. That means all entries are stored as write intents (pending entries) before they are committed. Those entries are required for transactional protocol and stored in in-memory collection (PartitionListener#txsPendingRowIds). The collection can be lost due to restart of the node where the data located. Recovery of the collection happens through scan of all entries in the partition and can take long time.

There are several possible ways to solve this problem: to persist pending rows collection, or resolve write intents when they are met by another transaction, including RW transactions. After some discussions the latter seems to be better decision, as it doesn't require one more persistent storage/structure, and RW transactions should be able to resolve write intents anyway.

Definition of Done
No full partition scan on start is needed.

Implementation notes
The chosen decision implies that unresolved write intents in partition can be present in partition, even if such write intents belong to transaction that was already committed or aborted. When another transaction (no matter read-only or read-write) meets such write-intent it tries to resolve it. If it belongs to transaction that was already finished, then local cleanup must be run for this write-intent. This means that the write intent should be committed or aborted as like it was processed by TxCleanupCommand, but locally, because the corresponding write intents on another nodes had to be already processed by transaction cleanup as normally.

Issue Links

• is blocked by: IGNITE-19573 Fix row if write intent rersolved as commited
• is blocked by: IGNITE-19570 Write intent resolution for RW transactions
• is caused by: IGNITE-18044 ItIgniteNodeRestartTest#testTwoNodesRestartDirect is failed after schema recovery fix.
• Is contained by: IGNITE-21176 Remove PendingRows collection
• is related to: IGNITE-17578 Transactions: async cleanup processing on tx commit