Upate garbage collection algorithm design #1061
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WalkthroughThe pull request modifies the document on garbage collection in CRDT systems to improve clarity and detail. Key updates include a refined definition of the "minVersionVector," an expanded explanation of the transition from Lamport timestamps to version vectors, and a new condition for garbage collection execution. Additionally, the handling of detached clients' lamports is clarified, and examples are enhanced for better understanding. Overall, the structure of the document is improved for readability. Changes
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🧹 Outside diff range and nitpick comments (2)
design/garbage-collection.md (2)
138-174: Comprehensive safety analysis with clear examples!The safety analysis is thorough and well-reasoned, effectively using concrete examples to demonstrate why the new GC condition is safe.
Consider these minor grammatical improvements:
- Line 139: Add a question mark: "...minVersionVector.minLamport()?"
- Line 166: Consider rephrasing to: "Since there's no direct way to determine this in the minimum version vector due to the absence of information..."
🧰 Tools
🪛 LanguageTool
[typographical] ~139-~139: Should there be a question mark at the end of this sentence?
Context: ...on vector and the minimum version vector. A version vector indicates the editing...(MISSING_QUESTION_MARK2)
175-214: Clear step-by-step examples with helpful diagrams!The examples effectively demonstrate the GC process through multiple states. The diagrams complement the explanations well.
Consider these readability improvements:
- Line 195: Change "for every clients" to "for every client"
- Line 195: Remove the comma before "because"
- Line 207 & 213: Add commas after "pushpull": "Client b pushpull, but nothing to push or pull."
🧰 Tools
🪛 LanguageTool
[uncategorized] ~195-~195: Possible missing article found.
Context: ...ent applies change4, the contents of document are changed toac. This time, all cli...(AI_HYDRA_LEO_MISSING_THE)
[grammar] ~195-~195: The noun should probably be in the singular form.
Context: ...t's still marked as tombstone for every clients, becauseminVersionVector[a] = 1 < 3...(EVERY_EACH_SINGULAR)
[formatting] ~195-~195: If the ‘because’ clause is essential to the meaning, do not use a comma before the clause.
Context: ...ll marked as tombstone for every clients, becauseminVersionVector[a] = 1 < 3### Sta...(COMMA_BEFORE_BECAUSE)
[uncategorized] ~207-~207: Possible missing comma found.
Context: ...e-collection-5.png)Client bpushpull but nothing to push or pull. `minVersionVec...(AI_HYDRA_LEO_MISSING_COMMA)
[uncategorized] ~213-~213: Possible missing comma found.
Context: ...e-collection-6.png)Client apushpull but nothing to push or pull. `minVersionVec...(AI_HYDRA_LEO_MISSING_COMMA)
🪛 Markdownlint
176-176: Punctuation: ':'
Trailing punctuation in heading(MD026, no-trailing-punctuation)
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⛔ Files ignored due to path filters (1)
design/media/remove-datached-clients-tombstone.jpgis excluded by!**/*.jpg
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design/garbage-collection.md(3 hunks)
🧰 Additional context used
🪛 LanguageTool
design/garbage-collection.md
[typographical] ~139-~139: Should there be a question mark at the end of this sentence?
Context: ...on vector and the minimum version vector. A version vector indicates the editing...
(MISSING_QUESTION_MARK2)
[uncategorized] ~195-~195: Possible missing article found.
Context: ...ent applies change 4, the contents of document are changed to ac. This time, all cli...
(AI_HYDRA_LEO_MISSING_THE)
[grammar] ~195-~195: The noun should probably be in the singular form.
Context: ...t's still marked as tombstone for every clients, because minVersionVector[a] = 1 < 3 ...
(EVERY_EACH_SINGULAR)
[formatting] ~195-~195: If the ‘because’ clause is essential to the meaning, do not use a comma before the clause.
Context: ...ll marked as tombstone for every clients, because minVersionVector[a] = 1 < 3 ### Sta...
(COMMA_BEFORE_BECAUSE)
[uncategorized] ~207-~207: Possible missing comma found.
Context: ...e-collection-5.png) Client b pushpull but nothing to push or pull. `minVersionVec...
(AI_HYDRA_LEO_MISSING_COMMA)
[uncategorized] ~213-~213: Possible missing comma found.
Context: ...e-collection-6.png) Client a pushpull but nothing to push or pull. `minVersionVec...
(AI_HYDRA_LEO_MISSING_COMMA)
🪛 Markdownlint
design/garbage-collection.md
176-176: Punctuation: ':'
Trailing punctuation in heading
(MD026, no-trailing-punctuation)
🔇 Additional comments (2)
design/garbage-collection.md (2)
Line range hint 42-54: Well-defined minVersionVector concept and GC conditions!
The explanation of minVersionVector and its safety guarantees for GC is clear and precise. The addition of the new condition removedAt.lamport < minVersionVector.minLamport() is well-documented.
125-137: Clear explanation of the detached client scenario!
The scenario with users A, B, and C effectively illustrates why the original GC condition was insufficient and why the additional condition was necessary. The technical explanation is thorough and well-reasoned.
What this PR does / why we need it:
Since GC algorithm has been updated, I updated design document.
Which issue(s) this PR fixes:
Fixes #
Special notes for your reviewer:
Does this PR introduce a user-facing change?:
Additional documentation:
Checklist:
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