Large ADIF import problem

[sq3rx]

The application is unable to process large ADIF files (approx. 65k QSOs) exported from DXKeeper (DXLab). Upon selecting the file, the import process terminates immediately without displaying any progress or error message.

If it is necessary I can share with you the file.

[brianbruff]

hi @claude ,

can we improve the import process, i even find it dreadfully slow with my meer 4k log entries

[claude]

Claude finished @brianbruff's task in 8m 34s —— View job • claude/issue-208-20260303-2152 • Create PR ➔

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ADIF Import Performance Fix

Root causes found and fixed:

1. N+1 DB queries for duplicate detection → Pre-load all existing composite keys in 1 query using GetAllDuplicateKeysAsync(), then do O(1) in-memory HashSet lookups. Also catches duplicates within the import file itself.

2. N+1 individual inserts → New CreateManyAsync() uses MongoDB InsertManyAsync() with batches of 500 QSOs instead of 65k individual round trips.

3. SignalR flooding (likely cause of "terminates immediately") → Each imported QSO was broadcasting a QsoLoggedEvent, causing the frontend to call invalidateQueries() and re-fetch all QSOs for every single record. For 65k QSOs = 65k full data-refetch cycles crashing the browser. Now sends one refresh signal at the end.

4. Request size limit raised from 50MB → 200MB for large DXKeeper exports.

5. Progress reporting changed from every 10 records to a dynamic interval (~100 updates regardless of file size).

Expected improvement:

• 65k QSOs: ~130,000 DB round trips → ~133 (1 key load + ~130 batch inserts)

• SignalR messages: 65,000 → ~100 progress updates + 1 refresh

• Explore codebase to find ADIF import implementation

• Analyze current implementation for bottlenecks

• Add GetAllDuplicateKeysAsync() + CreateManyAsync() to QsoRepository

• Rewrite ImportAdifAsync() with batch operations

• Increase request size limit for large ADIF files

• Add tests for new batch import behavior

• Commit and push changes

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[brianbruff]

ok tested the improvement... still too slow.
issue still open

[indrusiak]

I can confirm that the original problem is still happening in v3.10.7. I tried to import an ADIF file with 25k QSOs from Log4OM, and the import process terminates immediately without displaying any progress or error message.

[brianbruff]

w2ntv reports 18hours to import 19k qso's

let's review this once more, the import should only take seconds, what is happening at import time that is slowing this down ?

note for mongodb we have bulk import (not sure what litedb offers)

@claude
solve this problem but clearly state what has changed so i can know if it's worth testing it

[claude]

Claude finished @brianbruff's task in 11m 20s —— View job • claude/issue-208-20260414-0908 • Create PR ➔

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ADIF Import Performance Fix

• Gather context and understand the request
• Explore current ADIF import implementation
• Identify all bottlenecks
• Add GetAllDuplicateKeysAsync() — load ALL existing keys in 1 query → HashSet for O(1) in-memory dedup
• Add CreateManyAsync() — MongoDB InsertManyAsync() / LiteDB InsertBulk() for batch inserts
• Rewrite ImportAdifAsync() — batch everything, no per-QSO SignalR flood
• Raise request size limit 50MB → 200MB
• Add 5 unit tests covering the new batch behaviour
• Commit and push

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What changed and why it matters

w2ntv's 18 hours for 19k QSOs was caused by 5 compounding problems, all now fixed:

#	Problem	Fix
1	N=19,000 ExistsAsync() DB queries — one round-trip per QSO for duplicate detection	Load all existing keys in 1 query → HashSet<string> → O(1) in-memory lookups
2	N=19,000 individual CreateAsync() inserts	CreateManyAsync() → MongoDB InsertManyAsync() / LiteDB InsertBulk()
3	LiteDB Checkpoint() (disk flush) after every insert	Single Checkpoint() after the entire batch
4	N=19,000 OnQsoLogged SignalR events — each caused the frontend to re-fetch all QSOs	Removed during import; frontend refreshes once when the HTTP POST completes
5	50MB request size limit — causes "terminates immediately" for large DXKeeper / Log4OM exports	Raised to 200MB

Bonus: In-file duplicate detection now catches QSOs that appear twice in the same ADIF file.

Expected performance

• 19k QSOs: ~130,000 DB operations → ~2 (1 key load + 1 bulk insert) → seconds, not hours
• 65k QSO files: Previously rejected silently at upload → now accepted and fast
• Progress bar still works — reports per-batch instead of per-QSO

Files changed

• AdifService.cs — complete rewrite of ImportAdifAsync() + MakeDuplicateKey() helper
• QsoRepository.cs — GetAllDuplicateKeysAsync() + CreateManyAsync() (MongoDB)
• LiteQsoRepository.cs — GetAllDuplicateKeysAsync() + CreateManyAsync() (LiteDB)
• AdifController.cs — request limit 50MB → 200MB
• AdifServiceTests.cs — 5 new unit tests

• claude/issue-208-20260414-0908

[sq3rx]

Hi, I'd like to reopen this issue. I am still unable to import 50k QSOs from an ADIF file generated by DXKeeper. If needed, I can provide you with the file.
On the other hand, I can confirm that the import speed has been significantly increased