Advanced Query Processing Architecture

[everettbu]

Test 4

Summary by CodeRabbit

• Bug Fixes

  • Improved handling of template variables in queries to ensure they are correctly replaced before execution.

• Tests

  • Added and updated tests to verify that template variables in query expressions and steps are properly interpolated before queries run.

[coderabbitai]

Walkthrough

The changes update the query preparation logic in Loki's query splitting and sharding modules. Queries now have template variables interpolated using applyTemplateVariables per query, replacing previous bulk interpolation methods. Corresponding tests are updated to mock and verify this new interpolation approach, and additional test cases are added to ensure correct variable replacement.

Changes

File(s)	Change Summary
public/app/plugins/datasource/loki/querySplitting.ts	Refactored to interpolate template variables per query using applyTemplateVariables before splitting.
public/app/plugins/datasource/loki/shardQuerySplitting.ts	Updated to use per-query applyTemplateVariables for interpolation instead of bulk interpolation method.
public/app/plugins/datasource/loki/querySplitting.test.ts	Added test case to verify interpolation of template variables before query execution.
public/app/plugins/datasource/loki/shardQuerySplitting.test.ts	Updated mocks and expectations for new interpolation logic; added test for interpolation before execution.

Sequence Diagram(s)

sequenceDiagram
    participant User
    participant Datasource
    participant QuerySplitter

    User->>Datasource: Submit request with targets (may include template variables)
    Datasource->>QuerySplitter: Call runSplitQuery/runShardSplitQuery with request
    loop For each target in request.targets
        QuerySplitter->>Datasource: applyTemplateVariables(target, scopedVars, filters)
        Datasource-->>QuerySplitter: Interpolated target
    end
    QuerySplitter->>QuerySplitter: Split/interpolate queries as needed
    QuerySplitter-->>Datasource: Prepared queries
    Datasource-->>User: Query results

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Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

Poem

In burrows deep, the queries leap,
With variables now replaced,
Each hop precise, no step misplaced,
The tests all run, the logic neat—
A bunny’s work, interpolation complete!
🐇✨

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yarn install v1.22.22
[1/4] Resolving packages...
(node:17535) [DEP0169] DeprecationWarning: url.parse() behavior is not standardized and prone to errors that have security implications. Use the WHATWG URL API instead. CVEs are not issued for url.parse() vulnerabilities.
(Use node --trace-deprecation ... to show where the warning was created)
error Couldn't find any versions for "@grafana/data" that matches "workspace:*"
info Visit https://yarnpkg.com/en/docs/cli/install for documentation about this command.

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📜 Recent review details

Configuration used: CodeRabbit UI
Review profile: CHILL
Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between dcb853d and 3ba2457.

📒 Files selected for processing (4)

• public/app/plugins/datasource/loki/querySplitting.test.ts (1 hunks)
• public/app/plugins/datasource/loki/querySplitting.ts (1 hunks)
• public/app/plugins/datasource/loki/shardQuerySplitting.test.ts (4 hunks)
• public/app/plugins/datasource/loki/shardQuerySplitting.ts (1 hunks)

🧰 Additional context used

🧬 Code Graph Analysis (1)

public/app/plugins/datasource/loki/querySplitting.test.ts (1)

public/app/plugins/datasource/loki/querySplitting.ts (1)

• runSplitQuery (291-357)

🔇 Additional comments (6)

public/app/plugins/datasource/loki/querySplitting.test.ts (1)

75-88: LGTM! Well-structured test for template variable interpolation.

This test case properly validates the new per-query template variable interpolation behavior. The test setup correctly mocks the datasource's replace method and verifies that template variables ($__auto and $step) are interpolated to concrete values before query execution.

public/app/plugins/datasource/loki/querySplitting.ts (1)

296-299: Excellent improvement to template variable handling.

The change from bulk interpolation to per-query template variable application using applyTemplateVariables is a solid architectural improvement. This approach:

1. Provides more precise template variable interpolation per query
2. Properly utilizes scopedVars and filters parameters
3. Maintains the existing filtering logic while adding interpolation

The implementation is clean and follows the established pattern of chaining operations.

public/app/plugins/datasource/loki/shardQuerySplitting.ts (1)

49-52: Consistent implementation across query splitting mechanisms.

This change properly aligns the shard query splitting approach with the regular query splitting by applying the same per-query template variable interpolation pattern. The consistency between runSplitQuery and runShardSplitQuery is excellent for maintainability and ensures uniform behavior across different query splitting strategies.

public/app/plugins/datasource/loki/shardQuerySplitting.test.ts (3)

56-59: Properly updated mock to reflect API change.

The mock implementation correctly switches from interpolateVariablesInQueries to applyTemplateVariables, maintaining the same transformation logic while adapting to the new per-query processing approach.

---

84-101: Comprehensive test for template variable interpolation in shard splitting.

This test case effectively validates that template variables are properly interpolated before shard-based query execution. The test correctly verifies that both the query expression and step are interpolated, and that the sharding selector is properly applied to the interpolated query.

---

112-112: Correctly updated expectation for per-query processing.

The change from expecting 1 call to 5 calls properly reflects the shift from bulk interpolation to individual query processing. This aligns with the implementation change where applyTemplateVariables is now called once per query.

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• Post copyable unit tests in a comment
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[everettbu]

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This pull request has been automatically marked as stale because it has not had activity in the last 30 days. It will be closed in 2 weeks if no further activity occurs. Please feel free to give a status update or ping for review. Thank you for your contributions!

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This pull request has been automatically closed because it has not had any further activity in the last 2 weeks. Thank you for your contributions!