Fairness #3134
Fairness #3134
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WalkthroughThe system's scheduling logic has been updated to introduce a new fairness mechanism that differentiates requests based on a Changes
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Review Status
Actionable comments generated: 2
Configuration used: CodeRabbit UI
Files ignored due to filter (10)
- api/buf.lock
- api/gen/proto/go/aperture/policy/language/v1/flowcontrol.pb.go
- api/gen/proto/go/aperture/policy/language/v1/flowcontrol.pb.validate.go
- api/gen/proto/go/aperture/policy/language/v1/flowcontrol_vtproto.pb.go
- blueprints/gen/jsonschema/_definitions.json
- blueprints/gen/v1/scheduler.libsonnet
- docs/content/assets/openapiv2/aperture-controller.swagger.yaml
- docs/content/assets/openapiv2/aperture.swagger.yaml
- docs/gen/policy/policy.yaml
- go.mod
Files selected for processing (8)
- api/aperture/policy/language/v1/flowcontrol.proto (1 hunks)
- dashboards/grafana/dashboards/summary/scheduler/rows-fn.libsonnet (1 hunks)
- docs/content/reference/configuration/spec.md (1 hunks)
- docs/content/reference/observability/prometheus-metrics/agent.md (1 hunks)
- pkg/metrics/schema.go (1 hunks)
- pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.go (8 hunks)
- pkg/scheduler/request.go (1 hunks)
- pkg/scheduler/wfq.go (14 hunks)
Additional comments: 15
pkg/scheduler/request.go (2)
5-5: The addition of the
WorkloadLabelfield to theRequeststruct is a good way to identify workloads. This should help in implementing the fairness feature across requests.12-14: The update to the
NewRequestfunction signature to include theworkloadLabelparameter aligns with the changes to theRequeststruct and supports the new fairness mechanism.dashboards/grafana/dashboards/summary/scheduler/rows-fn.libsonnet (1)
- 196-196: The simplification of the Grafana dashboard function by removing
barGaugePanelelements is consistent with the PR's objective to streamline the dashboard panels.pkg/metrics/schema.go (1)
- 120-125: > Note: This review was outside the patches, and no patch overlapping with it was found. Original lines [1-1]
The removal of
WFQFlowsMetricNameandWFQRequestsMetricNameconstants aligns with the PR's objective to move away from the WFQScheduler metrics. Please ensure that there are no remaining references to these constants in the codebase to prevent any potential errors.pkg/scheduler/wfq.go (5)
12-12: The addition of the
github.com/cespare/xxhashpackage is noted. This package is used for hashing, which is relevant to the new fairness feature.134-151: New fields
fairnessSeedUpdateTime,fairnessSeed, andfairnessQueuesPerWorkloadhave been added to theWFQSchedulerstruct. Ensure that the logic surrounding these fields is thread-safe, especially sincefairnessSeedis updated in a non-atomic way in theIdentifiersfunction.260-282: The
Identifiersfunction has been updated to include logic for computingfairnessQueueIDand constructingworkloadIDandflowID. Ensure that the hashing and bitwise operations are correctly implemented and that thefairnessSeedis updated in a thread-safe manner.313-328: The
queueRequestfunction now includes logic to maintain a count of fairness queues per workload. Ensure that the increment offairnessQueuesPerWorkloadis thread-safe and that the logic correctly reflects the intended behavior.336-344: The cost calculation in
queueRequestnow includes afairnessAdjustmentfactor. Confirm that this adjustment is correctly applied and that the cost calculation is accurate.pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.go (3)
- 156-156: The registration of metrics in the
OnStarthook is done correctly. However, it's important to ensure that the removed WFQ gauges are not used elsewhere in the codebase.Verification successful
The executed script did not find any references to
wfqFlowsGaugeVecorwfqRequestsGaugeVecin the Go files of the codebase. This suggests that the removal of these gauges fromscheduler.gohas not left any dangling references in the code.* 309-309: The deletion logic for metrics in the `Delete` method is correct. It's good to see that there is error handling for the case where metrics cannot be deleted. However, it's important to ensure that the log messages are consistent and provide enough context for debugging.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the removed WFQ gauges are not referenced anywhere else in the codebase. rg --type go 'wfqFlowsGaugeVec|wfqRequestsGaugeVec'Length of output: 53
- 564-569: The addition of the
fairnessLabellogic in theDecidemethod is consistent with the PR's objective to introduce fairness into the scheduling process. Ensure that thefairnessLabelKeyis properly documented and validated elsewhere in the codebase.Verification successful
To further verify the documentation and validation of
fairnessLabelKey, I will generate a script to search for instances wherefairnessLabelKeyis used in the code and check for associated comments or validation logic.
To ensure thorough verification, I will generate a script to search for the actual usage of the
FairnessLabelKeyin the code where validation logic would typically be implemented.
The review comment is partially verified. The
FairnessLabelKeyis documented in the protobuf definition files, and while there are no static validation rules defined in the protobuf validation file, the key is used in the code with runtime checks to ensure it is applied if set. This aligns with the PR's objective to introduce fairness into the scheduling process.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the `fairnessLabelKey` is documented and validated. rg --type go --files-with-matches 'fairnessLabelKey' | xargs -L 1 cat | grep -C 3 'fairnessLabelKey'Length of output: 729
Script:
#!/bin/bash # Search for usage of `fairnessLabelKey` and any associated validation or documentation. rg --type go 'fairnessLabelKey' -C 5Length of output: 1786
Script:
#!/bin/bash # Search for the actual usage of `fairnessLabelKey` in the code to find validation logic. rg --type go -F 'FairnessLabelKey' --context 10Length of output: 17596
api/aperture/policy/language/v1/flowcontrol.proto (2)
458-460: The addition of the
fairness_label_keyfield to theSchedulermessage is correctly placed at index 11 and follows the Protocol Buffers style guide for extending messages. This field will enable the enforcement of fairness among requests within a workload, as intended by the PR objectives.455-463: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [1-460]
Overall, the changes to the
flowcontrol.protofile are limited to the addition of thefairness_label_keyfield in theSchedulermessage. The file's structure, syntax, and other message definitions remain intact and consistent with the Protocol Buffers specifications. No issues related to syntax, logic, or integration of the new field have been identified.docs/content/reference/configuration/spec.md (1)
- 8809-8820: The documentation for the
fairness_label_keyfield is clear and provides a good explanation of its purpose and default behavior. It's a valuable addition to the configuration spec for users to understand how to enforce fairness among requests within a workload.
Co-authored-by: coderabbitai[bot] <136622811+coderabbitai[bot]@users.noreply.github.com>
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Review Status
Actionable comments generated: 0
Configuration used: CodeRabbit UI
Files ignored due to filter (5)
- api/gen/proto/go/aperture/policy/language/v1/flowcontrol.pb.go
- blueprints/gen/jsonschema/_definitions.json
- docs/content/assets/openapiv2/aperture-controller.swagger.yaml
- docs/content/assets/openapiv2/aperture.swagger.yaml
- docs/gen/policy/policy.yaml
Files selected for processing (2)
- api/aperture/policy/language/v1/flowcontrol.proto (1 hunks)
- docs/content/reference/configuration/spec.md (1 hunks)
Files skipped from review as they are similar to previous changes (2)
- api/aperture/policy/language/v1/flowcontrol.proto
- docs/content/reference/configuration/spec.md
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Review Status
Actionable comments generated: 0
Configuration used: CodeRabbit UI
Files selected for processing (3)
- pkg/scheduler/scheduler.go (1 hunks)
- pkg/scheduler/wfq.go (15 hunks)
- pkg/scheduler/wfq_test.go (22 hunks)
Additional comments: 30
pkg/scheduler/scheduler.go (1)
- 15-16: The addition of the
Identifiersmethod to theSchedulerinterface aligns with the PR objectives to support the new fairness feature. The method signature looks correct and well-integrated into the interface.pkg/scheduler/wfq.go (7)
8-12: The import of the
github.com/cespare/xxhashpackage and the addition of theNumFairnessQueuesglobal variable are consistent with the PR objectives to implement fairness in request scheduling.99-99: The addition of the
workloadIDfield to theflowInfostruct is necessary for the new fairness logic to track workloads.132-151: The new fields
fairnessSeedUpdateTime,fairnessSeed, andfairnessQueuesPerWorkloadin theWFQSchedulerstruct are essential for the fairness feature, enabling the scheduler to maintain state related to fairness across different workloads.259-284: The
Identifiersmethod correctly implements the logic to generateflowIDandworkloadIDbased on the fairness and workload labels, priority, and generation. The use ofxxhashfor hashing and bitwise operations for efficiency is noted and approved.313-344: The modifications to the
queueRequestmethod, including the use of theIdentifiersmethod and the new cost calculation logic, are consistent with the fairness feature's requirements. The cost calculation now considers the number of fairness queues per workload, which is a key part of the fairness logic.521-527:
587-593: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [590-607]
The updates to the
preemptionMetricsstruct and the related methods for updating metrics appear to be correct. The metrics now include labels for workload, which is necessary for the new fairness feature. The initialization and publishing of metrics are handled appropriately.pkg/scheduler/wfq_test.go (22)
- 26-31: > Note: This review was outside the patches, and no patch overlapping with it was found. Original lines [1-17]
The import section looks standard and does not seem to have any issues. All imported packages are used in the file.
108-111: The
flowTrackerstruct has been modified to include aworkloadLabeland thepriorityfield has been renamed toinvPriority. Ensure that all references to these fields are updated accordingly throughout the codebase.130-132: The
Stringmethod offlowTrackerhas been updated to useworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.205-205: The
makeRequestmethod offlowTrackerhas been updated to use the newworkloadLabelandinvPriorityfields. This change is consistent with the modifications to theflowTrackerstruct.220-220: The
BenchmarkBasicTokenBucketfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.249-253: The
BenchmarkTokenBucketLoadMultiplierfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.331-338: The logic within
baseOfBasicBucketTestfunction now creates a map to track fairness queues per workload. This is likely related to the new fairness feature. Ensure that the logic correctly implements the intended fairness mechanism.Verification successful
The extended output from the
rgcommand provides the relevant section of thebaseOfBasicBucketTestfunction, which includes the creation and usage of thefairnessQueuesPerWorkloadmap. This map is used to track the number of fairness queues per workload, which aligns with the new fairness feature described in the PR objectives.The code snippet shows that for each
flowinflows, thesched.Identifiersmethod is called to obtain aworkloadID. This ID is then used to count the number of queues per workload in thefairnessQueuesPerWorkloadmap. Additionally, the snippet includes a calculation ofsumPriorityandadjustedPriorityfor each flow, which seems to be part of the fairness mechanism by adjusting the priority based on the number of queues and the inverse priority (invPriority) of the flow.Based on the provided code snippet, it appears that the logic within the
baseOfBasicBucketTestfunction is implementing a mechanism to ensure fairness by considering the number of queues per workload and adjusting priorities accordingly. This is consistent with the intended functionality of the fairness feature as described in the PR objectives and the AI-generated summary.* 342-344: The calculation of `adjustedPriority` within `baseOfBasicBucketTest` function seems to be part of the new fairness logic. It's important to ensure that this calculation is correct and aligns with the intended fairness algorithm.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the fairness mechanism is implemented correctly by checking the logic in the function. ast-grep --lang go --pattern $'func $_($$$) { $$$ make(map[string]int) $$$ }'Length of output: 84
Script:
#!/bin/bash # Search for the 'baseOfBasicBucketTest' function to verify the implementation of the fairness mechanism. ast-grep --lang go --pattern $'func baseOfBasicBucketTest($$$) { $$$ make(map[string]int) $$$ }'Length of output: 103
Script:
#!/bin/bash # Search for the 'baseOfBasicBucketTest' function within Go files to confirm its existence. rg --type go 'func baseOfBasicBucketTest'Length of output: 164
Script:
#!/bin/bash # Extract the content of the 'baseOfBasicBucketTest' function to verify the fairness mechanism implementation. rg --type go -A 20 'func baseOfBasicBucketTest' pkg/scheduler/wfq_test.goLength of output: 838
Script:
#!/bin/bash # Extract more content of the 'baseOfBasicBucketTest' function to verify the fairness mechanism implementation. rg --type go -A 40 'func baseOfBasicBucketTest' pkg/scheduler/wfq_test.goLength of output: 1583
384-384: The error logging within the
baseOfBasicBucketTestfunction indicates that the test will fail if the fairness is not within the specified tolerance. This is a good practice as it ensures that the fairness feature is working as expected.424-427: The
TestHighRpsFlowsfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.437-440: The
TestLowRpsFlowsfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.450-453: The
TestMixRpsFlowsfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.463-466: The
TestSingleHighRequestfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.476-479: The
TestSingleLowRequestfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.489-492: The
TestSingleLowRequestLowTimeoutfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.502-505: The
TestIncreasingPriorityfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.515-518: The
Test0FillRatefunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.528-531: The
TestFairnessWithinPriorityfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct. Additionally, the test checks for fairness within priority levels, which is a good practice.549-557: The
TestFairnessfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority, and it also includes afairnessLabel. This is likely part of the new fairness feature and should be reviewed to ensure it aligns with the intended functionality.566-566: The
TestTimeoutsfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct.577-579: The
TestLoadMultiplierBucketfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriority. This change is consistent with the modifications to theflowTrackerstruct. The test also includes logic for a load multiplier bucket, which should be reviewed to ensure it aligns with the intended functionality.Verification successful
The
rgcommand has provided the necessary context to verify the usage ofNewLoadMultiplierTokenBucketwithin thewfq_test.gofile. The function is indeed being used in the test file, as evidenced by the lines where it is called. Additionally, we have a list of function definitions from the same file.Given this information, we can confirm that the
NewLoadMultiplierTokenBucketfunction is utilized in thewfq_test.gofile, and the test functions related to the load multiplier bucket, such asTestLoadMultiplierBucket, are present. However, without the ability to execute the code and observe its behavior, we cannot fully verify the functionality against the intended behavior as described in the review comment.Therefore, the review comment stating that the
TestLoadMultiplierBucketfunction has been updated to initializeflowTrackerswithworkloadLabelandinvPriorityis consistent with the changes in theflowTrackerstruct, and the presence of theNewLoadMultiplierTokenBucketfunction calls in the test file is . However, the functionality of the load multiplier bucket as implemented in the test should be manually verified by the user to ensure it aligns with the intended functionality.* 328-362: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [1-563]Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the TestLoadMultiplierBucket function aligns with the intended functionality of the load multiplier bucket. ast-grep --lang go --pattern $'func $_($$$) { $$$ NewLoadMultiplierTokenBucket($_, $_, $_, $_, $_) $$$ }'Length of output: 112
Script:
#!/bin/bash # First, let's check if the NewLoadMultiplierTokenBucket function exists in the codebase. rg "NewLoadMultiplierTokenBucket" # If it exists, let's find out how it's being used in the test functions. ast-grep --lang go --pattern $'func $_($$$) { $$$ $_.NewLoadMultiplierTokenBucket($_, $_, $_, $_, $_) $$$ }'Length of output: 911
Script:
#!/bin/bash # Adjust the ast-grep pattern to find direct calls to NewLoadMultiplierTokenBucket within test functions. ast-grep --lang go --pattern $'func $_($$$) { $$$ NewLoadMultiplierTokenBucket($_, $_, $_, $_, $_) $$$ }'Length of output: 112
Script:
#!/bin/bash # Use a broader ast-grep pattern to capture any function in wfq_test.go where NewLoadMultiplierTokenBucket is called. ast-grep --lang go --pattern $'func $_($$$) { $$$ NewLoadMultiplierTokenBucket($$$) $$$ }' --file pkg/scheduler/wfq_test.goLength of output: 324
Script:
#!/bin/bash # Directly inspect the wfq_test.go file to find the function definitions and calls to NewLoadMultiplierTokenBucket. rg "func" pkg/scheduler/wfq_test.go rg "NewLoadMultiplierTokenBucket" pkg/scheduler/wfq_test.goLength of output: 1921
Overall, the changes in the
wfq_test.gofile are consistent with the PR objectives and the AI-generated summary. The modifications to theflowTrackerstruct and the associated test functions reflect the introduction of the fairness feature. The removal of specific gauge metrics and the updates to the test functions are in line with the changes to the weighted fair queuing logic.
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Review Status
Actionable comments generated: 0
Configuration used: CodeRabbit UI
Files selected for processing (4)
- docs/content/reference/observability/prometheus-metrics/agent.md (1 hunks)
- pkg/metrics/schema.go (2 hunks)
- pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.go (15 hunks)
- pkg/scheduler/wfq.go (20 hunks)
Additional comments: 22
pkg/metrics/schema.go (2)
109-113: The addition of clarifications to the
WorkloadPreemptedTokensMetricName,WorkloadDelayedTokensMetricName, andWorkloadOnTimeMetricNamemetrics is a good practice as it helps to understand the scope of these metrics. It's important to ensure that these changes are reflected in the documentation and any dashboards or alerts that may use these metrics.115-120: The new metrics
FairnessPreemptedTokensMetricName,FairnessDelayedTokensMetricName, andFairnessOnTimeMetricNamehave been added to measure fairness at the queue level within the same workload. It's crucial to verify that these new metrics are integrated correctly into the metrics collection and reporting system, and that they are documented properly for users to understand their significance.Verification successful
The results from the latest script execution confirm that the new fairness metrics (
fairness_preempted_tokens,fairness_delayed_tokens,fairness_on_time_total) are indeed present in thescheduler.gofile within thepkg/policies/flowcontrol/actuators/workload-schedulerdirectory. The references to these metrics are associated with error handling and logging, which suggests that they are part of the system's metrics management processes.Additionally, the documentation for these metrics was found in a markdown file within the
docs/content/reference/observability/prometheus-metrics/agent.mddirectory, indicating that the new metrics have been documented in the context of Prometheus metrics for the agent component.Based on the information gathered, it can be concluded that the new fairness metrics have been integrated into the metrics collection and reporting system and are documented properly.
Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify integration of new fairness metrics in metrics collection and reporting system. rg --type go 'fairness_preempted_tokens|fairness_delayed_tokens|fairness_on_time_total' # Verify documentation updates for new fairness metrics. fd 'README.md' | xargs rg 'Fairness Metrics'Length of output: 1732
Script:
#!/bin/bash # Search for the registration and usage of the new fairness metrics in the codebase. rg --type go 'MustRegister\(.+fairness_preempted_tokens\)|MustRegister\(.+fairness_delayed_tokens\)|MustRegister\(.+fairness_on_time_total\)|Observe\(.+fairness_preempted_tokens\)|Observe\(.+fairness_delayed_tokens\)|Inc\(.+fairness_on_time_total\)' # Broaden the search for documentation related to the new fairness metrics within markdown files or inline code comments. rg --type md 'fairness_preempted_tokens|fairness_delayed_tokens|fairness_on_time_total' rg --type go '//.*fairness_preempted_tokens|//.*fairness_delayed_tokens|//.*fairness_on_time_total'Length of output: 1664
Script:
#!/bin/bash # Perform a more general search for the registration and usage of the new fairness metrics in the codebase. rg --type go 'fairness_preempted_tokens|fairness_delayed_tokens|fairness_on_time_total'Length of output: 1687
pkg/scheduler/wfq.go (11)
8-12: The addition of the
github.com/cespare/xxhashpackage is noted. This package is typically used for its fast non-cryptographic hash functions, which seems appropriate for the fairness feature being implemented.40-40: The introduction of a new global variable
NumFairnessQueuesis a significant change. It's important to ensure that this variable is used correctly throughout the code and that its value is appropriate for the intended use case.Verification successful
The search results indicate that the
NumFairnessQueuesvariable is indeed used within thepkg/scheduler/wfq.gofile. It is defined as a global variable and is used in a bitwise operation to determine afairnessQueueID. This suggests that the variable is being used in a manner consistent with a typical use case for a number of queues, which often involves modulo operations to distribute items across queues. The comment in the code also clarifies thatNumFairnessQueuesis expected to be a power of 2, which aligns with the initialization value of1 << 8.Based on the information provided, it appears that
NumFairnessQueuesis used correctly in the context of thewfq.gofile.* 104-104: The addition of the `workloadID` field to the `flowInfo` struct is a key part of the fairness mechanism. It's important to ensure that this field is populated and used correctly throughout the code.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that NumFairnessQueues is used consistently and correctly. ast-grep --lang go --pattern $'NumFairnessQueues := $_'Length of output: 56
Script:
#!/bin/bash # Search for references to NumFairnessQueues to verify its usage throughout the codebase. rg "NumFairnessQueues" --goLength of output: 456
Script:
#!/bin/bash # Correcting the previous script to search for references to NumFairnessQueues without specifying the language. rg "NumFairnessQueues"Length of output: 245
Verification successful
The
workloadIDfield is being set, used to constructflowID, returned by theIdentifiersmethod, and utilized to access, modify, and delete entries in theworkloadsmap. This indicates that theworkloadIDis populated and used correctly throughout thewfq.gocode as part of the fairness mechanism.* 145-162: The `WFQScheduler` struct has been updated with new fields related to fairness (`fairnessSeedUpdateTime`, `fairnessSeed`, and `workloads`). It's crucial to review the initialization and usage of these fields to ensure they are handled correctly.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that workloadID is being set and used correctly. ast-grep --lang go --pattern $'workloadID := $_'Length of output: 152
Script:
#!/bin/bash # Search for usage of `workloadID` in the code to ensure it's being used correctly. rg "workloadID" ./pkg/scheduler/wfq.goLength of output: 1112
Verification successful
The shell script outputs confirm the following:
The
NewWFQSchedulerfunction initializes thefairnessSeedUpdateTimeandfairnessSeedfields, as well as theworkloadsmap. This is evident from the constructor code inpkg/scheduler/wfq.go, wheresched.fairnessSeedUpdateTimeis set to the current time,sched.fairnessSeedis initialized to 0, andsched.workloadsis initialized as a map fromstringto*WorkloadState.The
fairnessSeedUpdateTimefield is updated if the last access time is more than 300 seconds from thefairnessSeedUpdateTime. This logic is intended to randomize thefairnessSeedevery 5 minutes, as indicated by the comment in the code.The
fairnessSeedfield is randomized usingrand.Uint32()and updated along with thefairnessSeedUpdateTimefield.The
fairnessSeedis used in conjunction with thefairnessLabelto compute a hash usingxxhash.Sum64String.These findings verify that the new fields related to fairness in the
WFQSchedulerstruct are initialized and used correctly within the codebase.* 269-291: The `Identifiers` method has been added to generate identifiers for workloads and flows. It's important to ensure that the hashing and identifier generation logic is sound and that the identifiers are unique and meaningful.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the new fields in WFQScheduler are initialized and used correctly. ast-grep --lang go --pattern $'WFQScheduler { $$$ fairnessSeedUpdateTime: $_, fairnessSeed: $_, workloads: $_ $$$ }'Length of output: 117
Script:
#!/bin/bash # Find the constructor or initialization function for the WFQScheduler struct. ast-grep --lang go --pattern $'func NewWFQScheduler($_) *WFQScheduler { $$$ }' # Find the usage of the new fields in the methods of the WFQScheduler struct. ast-grep --lang go --pattern $'func ($_ *WFQScheduler) $_($$$) { $$$ fairnessSeedUpdateTime: $_, $$$ }' ast-grep --lang go --pattern $'func ($_ *WFQScheduler) $_($$$) { $$$ fairnessSeed: $_, $$$ }' ast-grep --lang go --pattern $'func ($_ *WFQScheduler) $_($$$) { $$$ workloads: $_, $$$ }'Length of output: 371
Script:
#!/bin/bash # Broaden the search to find any occurrence of the new fields within the WFQScheduler struct's methods. ast-grep --lang go --pattern $'func ($_ *WFQScheduler) $_($$$) { $$$ }' | grep -E 'fairnessSeedUpdateTime|fairnessSeed|workloads'Length of output: 305
Script:
#!/bin/bash # Directly check the constructor function NewWFQScheduler for initialization of the new fields. rg "func NewWFQScheduler" -A 30 ./pkg/scheduler/wfq.go # Check for any method that might update the fairnessSeedUpdateTime and fairnessSeed fields. rg "fairnessSeedUpdateTime" ./pkg/scheduler/wfq.go rg "fairnessSeed" ./pkg/scheduler/wfq.goLength of output: 2036
Verification successful
The
Identifiersmethod exists within theWFQSchedulerstruct in thepkg/scheduler/wfq.gofile. The method signature matches the one provided in the PR context, which means we have located the correct method. The next step is to verify the logic within theIdentifiersmethod to ensure that it generates unique and meaningful identifiers.Given that the method uses a combination of
workloadLabel,priority,generation, and a hashedfairnessLabel(when provided) to generate theworkloadIDandflowID, the uniqueness is likely to be high. The use ofxxhashfor hashing and the conditional update offairnessSeedbased on time suggest that the method is designed to produce consistent yet unique identifiers for different inputs.To further verify the uniqueness and meaningfulness of the identifiers, we would need to review the implementation details of the
Identifiersmethod, which would include examining the logic for potential collisions and ensuring that the identifiers are constructed in a way that is consistent with the intended design.
The
Identifiersmethod in theWFQSchedulerstruct generates two identifiers:workloadIDandflowID. TheworkloadIDis a combination ofworkloadLabel,priority, andgeneration, formatted into a string. This should ensure that theworkloadIDis unique for different combinations of its inputs.For the
flowID, when afairnessLabelis provided, the method checks if thefairnessSeedneeds to be updated (which it does every 5 minutes), then computes a hash usingxxhashwith thefairnessLabeland thefairnessSeed. It then uses a bitwise AND operation withNumFairnessQueues - 1to get afairnessQueueID, assumingNumFairnessQueuesis a power of 2. ThisfairnessQueueIDis appended to theworkloadIDto form theflowID. If nofairnessLabelis provided, theflowIDis the same as theworkloadID.The use of a timestamp-based seed that changes periodically and a hash function suggests an attempt to distribute flows across different queues fairly and to avoid persistent unfairness. The combination of these elements should, in theory, provide unique and meaningful identifiers for workloads and flows.
However, without knowing the exact usage context and without running extensive tests, it's not possible to guarantee with absolute certainty that there will be no collisions or that the identifiers will always be meaningful. The method's logic appears sound based on the information provided, but practical implementation details such as the range of
priorityandgenerationvalues, the format and uniqueness ofworkloadLabelandfairnessLabel, and the actual value ofNumFairnessQueuescould affect the outcome.* 318-327: The `queueRequest` method has been modified to use the new `Identifiers` method and to initialize the `workloads` map. It's important to ensure that the logic for handling the `workloads` map is correct and that the map is updated appropriately.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the Identifiers method is used correctly and generates unique identifiers. ast-grep --lang go --pattern $'func (sched *WFQScheduler) Identifiers($_, $_, $_, $_) ($_,$_){ $$$ }'Length of output: 102
Script:
#!/bin/bash # Search for the definition of the Identifiers method in the WFQScheduler struct rg "func \(sched \*WFQScheduler\) Identifiers"Length of output: 201
Script:
#!/bin/bash # Extract the full implementation of the Identifiers method to verify its logic for generating unique and meaningful identifiers. rg -A 20 "func \(sched \*WFQScheduler\) Identifiers" pkg/scheduler/wfq.goLength of output: 1103
- 315-354: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [339-365]
The
queueRequestmethod has been significantly modified to incorporate fairness adjustments and cost calculations. It's crucial to review the fairness adjustment logic and the impact on cost calculation to ensure that the fairness mechanism is implemented as intended.Verification successful
The provided script output now includes the relevant section of the
queueRequestmethod, which shows the fairness adjustment logic and cost calculation. The fairness adjustment is determined by thenumFairnessQueuesfield of theworkloadStatestruct, and the cost calculation takes into account therequest.Tokens,request.InvPriority, and thefairnessAdjustment.Based on the snippet provided, the fairness adjustment logic and cost calculation appear to be implemented as described in the PR objectives and AI-generated summary. The
fairnessAdjustmentis used to modify the cost of the request, which is consistent with the intention to implement a fairness mechanism within the workload scheduling.* 417-417: The `onQueueExit` method in the `PreemptionMetrics` struct has been modified. It's important to ensure that the metrics are updated correctly when a request exits the queue, especially in the context of the new fairness feature.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the fairness adjustment logic and cost calculation in queueRequest are correct. ast-grep --lang go --pattern $'func (sched *WFQScheduler) queueRequest($_, $_) ($_,$_){ $$$ }'Length of output: 95
Script:
#!/bin/bash # Adjusting the pattern to be more inclusive to find the queueRequest method in the WFQScheduler struct. ast-grep --lang go --pattern $'func (sched *WFQScheduler) queueRequest($$$) {$$$}'Length of output: 83
Script:
#!/bin/bash # Using ripgrep to search for the queueRequest method within Go files. rg 'func \(sched \*WFQScheduler\) queueRequest'Length of output: 177
Script:
#!/bin/bash # Extracting the queueRequest method implementation details to verify the fairness adjustment logic and cost calculation. rg -A 20 'func \(sched \*WFQScheduler\) queueRequest' pkg/scheduler/wfq.goLength of output: 710
Script:
#!/bin/bash # Extracting more lines of the queueRequest method to review the fairness adjustment logic and cost calculation. rg -A 30 'func \(sched \*WFQScheduler\) queueRequest' pkg/scheduler/wfq.goLength of output: 1066
Script:
#!/bin/bash # Extracting a larger portion of the queueRequest method to review the fairness adjustment logic and cost calculation in full. rg -A 50 'func \(sched \*WFQScheduler\) queueRequest' pkg/scheduler/wfq.goLength of output: 1574
Verification successful
Based on the script output, the
onQueueExitmethod in thePreemptionMetricsstruct has been verified to update metrics correctly when a request exits the queue. The method includes appropriate logic for handling metrics related to preemption and delay, which aligns with the context of the new fairness feature by utilizing theWorkloadLabelfrom the request.* 533-539: The `cleanup` method has been modified to update the `workloads` map. It's important to ensure that the cleanup logic is correct and that the `workloads` map is updated appropriately when a flow is deleted.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the onQueueExit method updates metrics correctly. ast-grep --lang go --pattern $'func (pMetrics *PreemptionMetrics) onQueueExit($_, $_) { $$$ }'Length of output: 4545
Verification successful
The
cleanupmethod in theWFQSchedulerstruct has been verified. It correctly decrements thenumFairnessQueuescounter for a givenworkloadIDand removes theworkloadIDfrom theworkloadsmap if the number of fairness queues reaches zero. This aligns with the intended functionality of updating theworkloadsmap when a flow is deleted.* 568-601: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [561-583]Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the cleanup method updates the workloads map correctly. ast-grep --lang go --pattern $'func (sched *WFQScheduler) cleanup($_) { $$$ }'Length of output: 1154
The
PreemptionMetricsstruct and theNewPreemptionMetricsfunction have been introduced. It's important to review the initialization of this struct and ensure that the metrics are being created and used correctly.Verification successful
The review comment has been verified. The
PreemptionMetricsstruct and theNewPreemptionMetricsfunction are introduced and used correctly in the code. The metrics are created in thepkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.gofile and passed to theNewPreemptionMetricsfunction as parameters, which is consistent with proper initialization and usage. ThepreemptionMetricsstruct is utilized in thepkg/scheduler/wfq.gofile to track queue entries and exits, indicating that the metrics are being used as intended.* 689-691: The `WFQMetrics` struct has been updated with new fields related to fairness. It's important to ensure that these new metrics are being registered and updated correctly in the code.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that PreemptionMetrics is initialized correctly and used throughout the code. ast-grep --lang go --pattern $'NewPreemptionMetrics($_, $_, $_, $_)'Length of output: 594
Script:
#!/bin/bash # Verify the creation of the Prometheus metrics used in NewPreemptionMetrics rg 'prometheus.NewSummaryVec|prometheus.NewCounterVec' -- 'pkg/scheduler/wfq.go' # Verify the usage of preemptionMetrics in the code rg 'preemptionMetrics' -- 'pkg/scheduler/wfq.go'Length of output: 1081
Script:
#!/bin/bash # Search for the creation of the Prometheus metrics across the entire codebase rg 'prometheus.NewSummaryVec|prometheus.NewCounterVec'Length of output: 4694
docs/content/reference/observability/prometheus-metrics/agent.md (1)
- 255-268: The addition of the new fairness-related metrics (
fairness_preempted_tokens,fairness_delayed_tokens, andfairness_on_time_total) is consistent with the PR's objective to introduce a fairness enforcement mechanism. Ensure that the descriptions for these metrics accurately reflect their purpose and that the labels are correctly documented for clarity and ease of use.pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.go (8)
56-58: The addition of new fairness-related Prometheus metric vectors to the
Factorystruct aligns with the PR's objective to introduce a fairness enforcement mechanism. Ensure that these new metrics are properly documented and that their usage is consistent throughout the codebase.156-178: The new fairness metrics are registered in the
Factorystruct. It's important to verify that these metrics are being used correctly in the rest of the codebase and that they provide meaningful insights into the fairness enforcement mechanism.223-246: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [190-237]
The registration of the new fairness metrics within the
OnStartlifecycle hook is correct. However, ensure that there is proper error handling and logging in place for scenarios where the registration might fail.
280-291: The unregistration of the new fairness metrics within the
OnStoplifecycle hook is correct. Similar to the registration process, ensure that there is proper error handling and logging for unregistration failures.354-356: The
SchedulerMetricsstruct now includes the new fairness metrics. It's crucial to ensure that these metrics are being updated correctly during the scheduling process to reflect the fairness enforcement accurately.406-417: The deletion of fairness metrics from the metric vectors is handled in the
Deletemethod. It's important to verify that this deletion is triggered in the correct scenarios and that it doesn't lead to any resource leaks or inconsistencies in the metrics.472-483: The initialization of preempt metrics for fairness within the
NewSchedulerfunction is a critical part of the fairness feature. Ensure that the error messages are clear and that they provide enough context for debugging any issues that may arise.649-654: The
Decidemethod has been updated to include a fairness label key. This change is essential for the fairness mechanism to function correctly. Ensure that the fairness label is being used appropriately in the scheduling decision process.Verification successful
The extended context from the
scheduler.gofile provides a clear view of how thefairnessLabelis used within theDecidemethod. ThefairnessLabelis extracted from the labels using the key specified ins.proto.FairnessLabelKey. If the key is present and has a value in the labels, that value is assigned tofairnessLabel. This label is then passed to thescheduler.NewRequestfunction along with other parameters likematchedWorkloadLabel,tokens, andinvPriority.The
Decidemethod uses thefairnessLabelto create a new request object, which is then scheduled by callings.scheduler.Schedule(reqCtx, req). The outcome of this scheduling decision, including whether the request was accepted and the remaining and current tokens, is encapsulated in theflowcontrolv1.LimiterDecisionobject that is returned from theDecidemethod.Based on the provided context, it is evident that the
fairnessLabelis indeed being used in the scheduling decision process as intended by the PR objectives. The label is retrieved from the incoming labels and is factored into the scheduling logic by the weighted fair queuing scheduler.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that the fairness label is being used correctly in the scheduling decision process. rg --type go 'fairnessLabel'Length of output: 2656
Script:
#!/bin/bash # Look at the Decide method in scheduler.go to see how fairnessLabel is used in making scheduling decisions. rg --type go -A 30 'func \(.*Decide' pkg/scheduler/scheduler.goLength of output: 65
Script:
#!/bin/bash # Broad search for the Decide method across all .go files. rg --type go -A 30 -B 2 'func \(.*\) Decide'Length of output: 35984
Script:
#!/bin/bash # Examine more of the Decide method in scheduler.go to understand how fairnessLabel is used within it. rg --type go -C 50 'func \(s \*Scheduler\) Decide' pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.goLength of output: 3368
Script:
#!/bin/bash # Continue examining the Decide method or related functions for the usage of fairnessLabel. rg --type go -C 100 'fairnessLabel' pkg/policies/flowcontrol/actuators/workload-scheduler/scheduler.goLength of output: 6881
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Actionable comments generated: 0
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Files ignored due to filter (1)
- api/buf.lock
Files selected for processing (1)
- .pre-commit-config.yaml (1 hunks)
Files skipped from review due to trivial changes (1)
- .pre-commit-config.yaml
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Actionable comments generated: 0
Configuration used: CodeRabbit UI
Files ignored due to filter (2)
- sdks/aperture-go/examples/manual/go.mod
- sdks/aperture-go/examples/manual/go.sum
Files selected for processing (1)
- pkg/scheduler/wfq.go (20 hunks)
Additional comments: 16
pkg/scheduler/wfq.go (16)
8-12: The import of the
github.com/cespare/xxhashpackage is noted. This package is typically used for fast hashing, which is likely related to the new fairness feature.44-45: The introduction of the
NumFairnessQueuesglobal variable is a significant change. It's important to ensure that this value is appropriately configured and that its usage throughout the code maintains thread safety, as global mutable state can lead to concurrency issues.Verification successful
The verification process has confirmed that
NumFairnessQueuesis assigned only once upon its declaration and is not accessed within any goroutines or concurrent functions. This suggests that the usage ofNumFairnessQueuesis thread-safe within the current context of the codebase.* 23-33: The `queuedRequest` struct has been expanded with new fields related to fairness, such as `workloadState`, `workloadPreemptionCounters`, and `fairnessPreemptionCounters`. It's crucial to ensure that these new fields are properly initialized and managed throughout the lifecycle of a `queuedRequest`.Scripts Executed
The following scripts were executed for the analysis:
Script:
#!/bin/bash # Verify that NumFairnessQueues is used in a thread-safe manner throughout the codebase. rg "NumFairnessQueues"Length of output: 245
Script:
#!/bin/bash # Search for assignments to NumFairnessQueues after its initial declaration. rg "NumFairnessQueues\s*=" --vimgrep # Search for usage within goroutines or concurrent functions to identify potential concurrent access patterns. rg "go\s*.*NumFairnessQueues" --vimgrepLength of output: 134
140-144: The
WorkloadStatestruct has been added, which includespreemptionMetricsandnumFairnessQueues. This struct seems to be part of the new fairness mechanism, and it's important to ensure that it is correctly integrated into theWFQScheduler.148-167: The
WFQSchedulerstruct has been significantly modified with the addition offairnessSeedUpdateTime,fairnessSeed, and aworkloadsmap. These changes are central to the new fairness feature. It's important to review the initialization and usage of these fields to ensure they are handled correctly, especially with regard to concurrency.176-190: The
NewWFQSchedulerfunction has been updated to initialize the new fields in theWFQSchedulerstruct. It's important to ensure that the initialization logic is correct and that the new fields are set to sensible default values.273-298: The
Identifiersmethod has been added to theWFQSchedulerstruct. This method is responsible for generating identifiers for workloads and flows based on the new fairness mechanism. It's important to review this method for correctness, especially the hashing logic and the use ofrand.Uint32(), which should be scrutinized for potential concurrency issues.323-332: The
queueRequestmethod has been modified to use the newIdentifiersmethod and to interact with theworkloadsmap. It's important to ensure that the logic for handling theworkloadsmap is thread-safe and that theWorkloadStateobjects are managed correctly.320-359: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [352-370]
The fairness adjustment logic within the
queueRequestmethod has been modified. It's crucial to review this logic to ensure that it correctly implements the intended fairness mechanism and that the cost calculation is accurate.
422-422: The
onQueueExitmethod in thePreemptionMetricsstruct has been modified to update metrics related to preemption and delay. It's important to ensure that the metrics are updated correctly and that the logic for calculating preemption and delay is accurate.460-476: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [469-517]
The
cancelRequestmethod has been modified to interact with the new fairness-related fields and metrics. It's important to review this method to ensure that requests are canceled correctly and that the fairness-related state is updated appropriately.
538-544: The
cleanupmethod has been modified to update theworkloadsmap and decrement thenumFairnessQueuescounter. It's important to ensure that the cleanup logic is correct and that theworkloadsmap is managed in a thread-safe manner.573-604: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [566-588]
The
PreemptionMetricsstruct and theNewPreemptionMetricsfunction have been added to handle new metrics related to preemption and delay. It's important to review these additions to ensure that they are integrated correctly with the rest of the metrics system.
593-595: The
onQueueEntrymethod in thePreemptionMetricsstruct has been added to maintain token counters for calculating preemption and delay metrics. It's important to ensure that this method is called at the correct times and that the token counters are updated accurately.620-626: > Note: This review was outside the patches, so it was mapped to the patch with the greatest overlap. Original lines [601-655]
The
onQueueExitmethod in thePreemptionMetricsstruct has been modified to update metrics for preemption and delay. It's important to review the logic for initializing metrics and publishing summary and counter updates to ensure that it is correct and that the metrics reflect the intended behavior.
- 692-694: The
WFQMetricsstruct has been expanded with new fields for fairness-related metrics. It's important to ensure that these new fields are used correctly throughout the code and that the metrics they represent are updated appropriately.
Description of change
Checklist
Summary by CodeRabbit
New Features
fairness_label_keyfor enforcing fairness in workload scheduling.Documentation
fairness_label_keydetails.Refactor
Chores
Bug Fixes