[IGNITE-5184] Collect write behind batch with out of order

• Type: Improvement
• Status: Open
• Priority: Major
• Resolution: Unresolved
• Assignee: Unassigned
• Reporter: Alexander Belyak
• Created: 10/May/17 03:09
• Updated: 10/May/17 03:09

Description

Now write behind flusher trying to batch cache operation with only natural order, i.e. if cache have "insert1, update2, delete3, insert4, delete5" operations it will be splitted to 4 batch opearations:
1) insert1, update2
2) delete3
3) insert4
4) delete5
Or even worse if we have two flush threads (they can get operation as:
1 thread: 1) insert1
2 thread: 1) update2
1 thread: 2) delete3
2 thread: 2) insert4
1 thread: 3) delete5
And we get 5 "batch" operation with store.
Because we already don't have real historical order in WB (with insert key1=1, delete key2, update key1=3 store wil get writeAll(key1=3) and then deleteAll(key2) operations) - it will be better if flusher thying to skip cache entries with different operation, i.e.process first example as:
1) insert1, update2, insert4 (skip delete3 and process it later)
2) delete3, delete5 (process delete3 operation)

Issue Links

• is related to: IGNITE-4927 Write behind - add an option to skip write coalescing