Add prewarm parameters

[eatbreads]

Summary by CodeRabbit

• New Features
  • Added a new configuration option to control cloud cache prewarming for the Eloq store (disabled by default). This allows admins to enable prewarming of the store's cloud cache on startup to potentially improve initial access performance.

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All committers have signed the CLA.

[coderabbitai]

Walkthrough

Adds a new boolean global option storage.eloq.storage.eloqStorePrewarmCloudCache (default false), persists it into EloqGlobalOptions, and wires it into the Eloq KV engine so prewarm_cloud_cache in the store config is initialized from that option during engine setup.

Changes

Cohort / File(s)	Summary
Eloq global options src/mongo/db/modules/eloq/src/eloq_global_options.h, src/mongo/db/modules/eloq/src/eloq_global_options.cpp	Add bool eloqStorePrewarmCloudCache{false} to EloqGlobalOptions; register and parse storage.eloq.storage.eloqStorePrewarmCloudCache and store the value during initialization.
KV engine → store config wiring src/mongo/db/modules/eloq/src/eloq_kv_engine.cpp	Read eloqStorePrewarmCloudCache from EloqGlobalOptions and initialize prewarm_cloud_cache in the EloqStoreConfig used by the engine.

Sequence Diagram

sequenceDiagram
    participant Config as Configuration Source
    participant GlobalOpts as EloqGlobalOptions
    participant KVEngine as EloqKVEngine
    participant Store as EloqStore

    Config->>GlobalOpts: Parse storage.eloq.storage.eloqStorePrewarmCloudCache
    GlobalOpts->>GlobalOpts: Set eloqStorePrewarmCloudCache (bool)
    KVEngine->>GlobalOpts: Read eloqStorePrewarmCloudCache
    KVEngine->>Store: Set prewarm_cloud_cache in store config
    Store->>Store: Apply prewarm_cloud_cache behavior on startup

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Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Focus review on correct option registration, parsing, default value, and propagation to engine config.
• Pay extra attention to header/API visibility and any config name typos.

Possibly related PRs

• fix overflowed parameter and add missed parameters #291 — Modifies the same Eloq global options and store configuration files; likely overlaps in option additions and wiring.

Suggested reviewers

• xiexiaoy
• yi-xmu
• lzxddz

Poem

🐰 I nibble configs, soft and neat,
A little flag makes startup sweet,
Prewarm the cloud with tender care,
Eloq hops ready — caches fair! 🥕✨

Pre-merge checks and finishing touches

❌ Failed checks (1 warning, 1 inconclusive)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 0.00% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.
Title check	❓ Inconclusive	The title 'Add prewarm parameters' is vague and generic, using non-descriptive language that doesn't clearly convey what specific prewarm parameters are being added or their purpose.	Enhance the title to be more specific, such as 'Add EloqStore cloud cache prewarm option' or 'Add prewarm cloud cache configuration parameter' to clearly indicate the feature being added.

✅ Passed checks (1 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (1)

src/mongo/db/modules/eloq/src/eloq_global_options.cpp (1)

577-582: Option registration matches existing EloqStore patterns

The new storage.eloq.storage.eloqStorePrewarmCloudCache option (and its short form) is wired in the same way as neighboring EloqStore flags, with a sane default and clear description. No issues from the parsing/constraints side.

If you want slightly better discoverability, you might consider grouping this closer to eloqStoreCloudStorePath, since it’s cloud-specific, but that’s purely organizational.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 2c00cc9 and 780683e.

📒 Files selected for processing (3)

• src/mongo/db/modules/eloq/src/eloq_global_options.cpp (2 hunks)
• src/mongo/db/modules/eloq/src/eloq_global_options.h (1 hunks)
• src/mongo/db/modules/eloq/src/eloq_kv_engine.cpp (1 hunks)

🚧 Files skipped from review as they are similar to previous changes (1)

• src/mongo/db/modules/eloq/src/eloq_kv_engine.cpp

🔇 Additional comments (2)

src/mongo/db/modules/eloq/src/eloq_global_options.h (1)

121-149: New eloqStorePrewarmCloudCache field is consistent with existing EloqStore options

The added boolean member, its default initialization, and placement among the other EloqStore flags look consistent with the surrounding pattern and with how it’s parsed in the .cpp file.

src/mongo/db/modules/eloq/src/eloq_global_options.cpp (1)

1079-1082: Parsing logic for eloqStorePrewarmCloudCache is correct; just ensure downstream handling is safe

The store logic cleanly mirrors other boolean options: guarded by params.count(...) and assigning to the new struct field with the expected type. No correctness issues here.

If you haven’t already, double‑check that callers (e.g., in eloq_kv_engine.cpp) handle eloqStorePrewarmCloudCache == true gracefully when cloud store is disabled (empty eloqStoreCloudStorePath), so enabling this flag alone can’t produce surprising startup failures.