Provide additional explanation for GC design document. #1073
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🧹 Outside diff range and nitpick comments (3)
design/garbage-collection.md (3)
177-178: Improve clarity and fix grammatical issues.The technical explanation is accurate but needs some grammatical improvements.
Consider this revision:
-Since minVersionVector is consist of lamport from active clients, there's a case where min version vector is empty. -Think about the case there's only one active client remains, and that client deactivates. After server receives deactivate request, it delete client's version vector from VersionVector table. When server compute minVersionVector for response pack with there's no active client, which means version vector table is empty, the result of computed min version vector is empty. When client receives response and applying it, GC runs +Since minVersionVector consists of Lamport timestamps from active clients, it can become empty in certain cases. +Consider a scenario where only one active client remains and that client deactivates. After the server receives the deactivate request, it deletes the client's version vector from the VersionVector table. When the server computes minVersionVector for the response packet and there are no active clients (meaning the version vector table is empty), the computed min version vector will be empty. When the client receives and applies this response, GC runs.🧰 Tools
🪛 LanguageTool
[grammar] ~177-~177: Consider using either the past participle “consisted” or the present participle “consisting” here.
Context: ...tor is empty? Since minVersionVector is consist of lamport from active clients, there's...(BEEN_PART_AGREEMENT)
[uncategorized] ~178-~178: Possible missing article found.
Context: ...ins, and that client deactivates. After server receives deactivate request, it delete ...(AI_HYDRA_LEO_MISSING_THE)
[uncategorized] ~178-~178: Possible missing article found.
Context: ...ient deactivates. After server receives deactivate request, it delete client's version vec...(AI_HYDRA_LEO_MISSING_THE)
[grammar] ~178-~178: After ‘it’, use the third-person verb form “deletes”.
Context: ... server receives deactivate request, it delete client's version vector from VersionVec...(IT_VBZ)
[typographical] ~178-~178: Consider adding a comma.
Context: ... minVersionVector for response pack with there's no active client, which means version...(IF_THERE_COMMA)
180-182: Consider adding a code example.The explanation of returning int64max and its implications for GC is clear and accurate. However, a code example would help readers better understand this behavior.
Consider adding a simple code example like:
For example: ```go func (vv VersionVector) minLamport() int64 { if len(vv) == 0 { return math.MaxInt64 // Returns int64max when empty } // ... normal min calculation }
184-186: Consider strengthening the safety argument.The rationale for using int64max and removing all tombstones is well-explained. However, it would be valuable to explicitly state that this design ensures consistency because:
- No active clients means no ongoing operations
- Future clients will start fresh with the cleaned state
Consider adding these points to reinforce the safety argument.
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🪛 LanguageTool
design/garbage-collection.md
[grammar] ~177-~177: Consider using either the past participle “consisted” or the present participle “consisting” here.
Context: ...tor is empty? Since minVersionVector is consist of lamport from active clients, there's...
(BEEN_PART_AGREEMENT)
[uncategorized] ~178-~178: Possible missing article found.
Context: ...ins, and that client deactivates. After server receives deactivate request, it delete ...
(AI_HYDRA_LEO_MISSING_THE)
[uncategorized] ~178-~178: Possible missing article found.
Context: ...ient deactivates. After server receives deactivate request, it delete client's version vec...
(AI_HYDRA_LEO_MISSING_THE)
[grammar] ~178-~178: After ‘it’, use the third-person verb form “deletes”.
Context: ... server receives deactivate request, it delete client's version vector from VersionVec...
(IT_VBZ)
[typographical] ~178-~178: Consider adding a comma.
Context: ... minVersionVector for response pack with there's no active client, which means version...
(IF_THERE_COMMA)
🔇 Additional comments (1)
design/garbage-collection.md (1)
176-176: LGTM! Good addition to cover this edge case.
The new section appropriately addresses an important scenario in the GC design.
What this PR does / why we need it:
I just added additional explanation for GC for the case when last active client deactivates.
It leads to a such result that min version vector is empty.
VersionVector.minLamport()returns int64max value when min version vector is empty, this is because empty min version vector means there's no more client using document and it means its safe to run GC to remove all tombstones.By the way, this concept can lead readers to confusion, I just added additional explanation of such case.
Which issue(s) this PR fixes:
Fixes #
Special notes for your reviewer:
Does this PR introduce a user-facing change?:
Additional documentation:
Checklist:
Summary by CodeRabbit
minVersionVectorscenarios.