Remove prioritize-query-components flag

CHANGELOG.md

@@ -45,6 +45,7 @@
   * `-memberlist.acquire-writer-timeout`
 * [ENHANCEMENT] memberlist: Notifications can now be processed once per interval specified by `-memberlist.notify-interval` to reduce notify storm CPU activity in large clusters. #9594
 * [ENHANCEMENT] Return server-side total bytes processed statistics as a header through query frontend. #9645
+* [ENHANCEMENT] Query-scheduler: Remove the experimental `query-scheduler.prioritize-query-components` flag. Request queues always prioritize query component dequeuing above tenant fairness. #9703
 * [BUGFIX] Fix issue where functions such as `rate()` over native histograms could return incorrect values if a float stale marker was present in the selected range. #9508
 * [BUGFIX] Fix issue where negation of native histograms (eg. `-some_native_histogram_series`) did nothing. #9508
 * [BUGFIX] Fix issue where `metric might not be a counter, name does not end in _total/_sum/_count/_bucket` annotation would be emitted even if `rate` or `increase` did not have enough samples to compute a result. #9508

cmd/mimir/config-descriptor.json

@@ -16385,17 +16385,6 @@
           "fieldFlag": "query-scheduler.max-outstanding-requests-per-tenant",
           "fieldType": "int"
         },
-        {
-          "kind": "field",
-          "name": "prioritize_query_components",
-          "required": false,
-          "desc": "When enabled, the query scheduler primarily prioritizes dequeuing fairly from queue components and secondarily prioritizes dequeuing fairly across tenants. When disabled, the query scheduler primarily prioritizes tenant fairness.",
-          "fieldValue": null,
-          "fieldDefaultValue": false,
-          "fieldFlag": "query-scheduler.prioritize-query-components",
-          "fieldType": "boolean",
-          "fieldCategory": "experimental"
-        },
         {
           "kind": "field",
           "name": "querier_forget_delay",

cmd/mimir/help-all.txt.tmpl

@@ -2315,8 +2315,6 @@ Usage of ./cmd/mimir/mimir:
     	Maximum number of outstanding requests per tenant per query-scheduler. In-flight requests above this limit will fail with HTTP response status code 429. (default 100)
   -query-scheduler.max-used-instances int
     	The maximum number of query-scheduler instances to use, regardless how many replicas are running. This option can be set only when -query-scheduler.service-discovery-mode is set to 'ring'. 0 to use all available query-scheduler instances.
-  -query-scheduler.prioritize-query-components
-    	[experimental] When enabled, the query scheduler primarily prioritizes dequeuing fairly from queue components and secondarily prioritizes dequeuing fairly across tenants. When disabled, the query scheduler primarily prioritizes tenant fairness.
   -query-scheduler.querier-forget-delay duration
     	[experimental] If a querier disconnects without sending notification about graceful shutdown, the query-scheduler will keep the querier in the tenant's shard until the forget delay has passed. This feature is useful to reduce the blast radius when shuffle-sharding is enabled.
   -query-scheduler.ring.consul.acl-token string

development/mimir-microservices-mode/config/mimir.yaml

@@ -164,7 +164,6 @@ querier:
 query_scheduler:
   # Change to "dns" to switch to query-scheduler DNS-based service discovery.
   service_discovery_mode: "ring"
-  prioritize_query_components: true
 
 limits:
   # Limit max query time range to 31d

docs/sources/mimir/configure/configuration-parameters/index.md

@@ -1718,13 +1718,6 @@ The `query_scheduler` block configures the query-scheduler.
 # CLI flag: -query-scheduler.max-outstanding-requests-per-tenant
 [max_outstanding_requests_per_tenant: <int> | default = 100]
 
-# (experimental) When enabled, the query scheduler primarily prioritizes
-# dequeuing fairly from queue components and secondarily prioritizes dequeuing
-# fairly across tenants. When disabled, the query scheduler primarily
-# prioritizes tenant fairness.
-# CLI flag: -query-scheduler.prioritize-query-components
-[prioritize_query_components: <boolean> | default = false]
-
 # (experimental) If a querier disconnects without sending notification about
 # graceful shutdown, the query-scheduler will keep the querier in the tenant's
 # shard until the forget delay has passed. This feature is useful to reduce the

pkg/frontend/v1/frontend.go

@@ -126,7 +126,6 @@ func New(cfg Config, limits Limits, log log.Logger, registerer prometheus.Regist
 	f.requestQueue, err = queue.NewRequestQueue(
 		log,
 		cfg.MaxOutstandingPerTenant,
-		false, //prioritizeQueryComponents -- currently no-op
 		cfg.QuerierForgetDelay,
 		f.queueLength,
 		f.discardedRequests,

pkg/scheduler/queue/multi_queuing_algorithm_tree_queue_benchmark_test.go

@@ -377,13 +377,9 @@ func TestMultiDimensionalQueueAlgorithmSlowConsumerEffects(t *testing.T) {
 	for _, weightedQueueDimensionTestCase := range weightedQueueDimensionTestCases {
 		numTenants := len(weightedQueueDimensionTestCase.tenantQueueDimensionsWeights)
 
-		tqaNonFlipped := tree.NewTenantQuerierQueuingAlgorithm()
 		tqaFlipped := tree.NewTenantQuerierQueuingAlgorithm()
 		tqaQuerierWorkerPrioritization := tree.NewTenantQuerierQueuingAlgorithm()
 
-		nonFlippedRoundRobinTree, err := tree.NewTree(tqaNonFlipped, tree.NewRoundRobinState())
-		require.NoError(t, err)
-
 		flippedRoundRobinTree, err := tree.NewTree(tree.NewRoundRobinState(), tqaFlipped)
 		require.NoError(t, err)
 
@@ -396,11 +392,6 @@ func TestMultiDimensionalQueueAlgorithmSlowConsumerEffects(t *testing.T) {
 			tqa  *tree.TenantQuerierQueuingAlgorithm
 		}{
 			// keeping these names the same length keeps logged results aligned
-			{
-				"tenant-querier -> query component round-robin tree",
-				nonFlippedRoundRobinTree,
-				tqaNonFlipped,
-			},
 			{
 				"query component round-robin -> tenant-querier tree",
 				flippedRoundRobinTree,
@@ -424,14 +415,10 @@ func TestMultiDimensionalQueueAlgorithmSlowConsumerEffects(t *testing.T) {
 				queryComponentQueueDurationObservations: map[string][]float64{},
 			}
 
-			// only the non-flipped tree uses the old tenant -> query component hierarchy
-			prioritizeQueryComponents := scenario.tree != nonFlippedRoundRobinTree
-
 			t.Run(testCaseName, func(t *testing.T) {
 				queue, err := NewRequestQueue(
 					log.NewNopLogger(),
 					maxOutStandingPerTenant,
-					prioritizeQueryComponents,
 					querierForgetDelay,
 					promauto.With(nil).NewGaugeVec(prometheus.GaugeOpts{}, []string{"user"}),
 					promauto.With(nil).NewCounterVec(prometheus.CounterOpts{}, []string{"user"}),
@@ -447,7 +434,6 @@ func TestMultiDimensionalQueueAlgorithmSlowConsumerEffects(t *testing.T) {
 					tenantsByID:      make(map[string]*queueTenant),
 					queuingAlgorithm: scenario.tqa,
 				}
-				queue.queueBroker.prioritizeQueryComponents = prioritizeQueryComponents
 				queue.queueBroker.tree = scenario.tree
 
 				ctx := context.Background()

pkg/scheduler/queue/queue.go

@@ -210,7 +210,6 @@ type requestToEnqueue struct {
 func NewRequestQueue(
 	log log.Logger,
 	maxOutstandingPerTenant int,
-	prioritizeQueryComponents bool,
 	forgetDelay time.Duration,
 	queueLength *prometheus.GaugeVec,
 	discardedRequests *prometheus.CounterVec,
@@ -246,7 +245,7 @@ func NewRequestQueue(
 		waitingDequeueRequestsToDispatch: list.New(),
 
 		QueryComponentUtilization: queryComponentCapacity,
-		queueBroker:               newQueueBroker(maxOutstandingPerTenant, prioritizeQueryComponents, forgetDelay),
+		queueBroker:               newQueueBroker(maxOutstandingPerTenant, forgetDelay),
 	}
 
 	q.Service = services.NewBasicService(q.starting, q.running, q.stop).WithName("request queue")

pkg/scheduler/queue/queue_broker.go

@@ -33,31 +33,20 @@ type queueBroker struct {
 	tenantQuerierAssignments *tenantQuerierShards
 	querierConnections       *querierConnections
 
-	maxTenantQueueSize        int
-	prioritizeQueryComponents bool
+	maxTenantQueueSize int
 }
 
 func newQueueBroker(
 	maxTenantQueueSize int,
-	prioritizeQueryComponents bool,
 	forgetDelay time.Duration,
 ) *queueBroker {
 	qc := newQuerierConnections(forgetDelay)
 	tqas := newTenantQuerierAssignments()
 	var treeQueue tree.Tree
 	var err error
-	var algos []tree.QueuingAlgorithm
-	if prioritizeQueryComponents {
-		algos = []tree.QueuingAlgorithm{
-			tree.NewQuerierWorkerQueuePriorityAlgo(), // root; algorithm selects query component based on worker ID
-			tqas.queuingAlgorithm,                    // query components; algorithm selects tenants
-
-		}
-	} else {
-		algos = []tree.QueuingAlgorithm{
-			tqas.queuingAlgorithm,     // root; algorithm selects tenants
-			tree.NewRoundRobinState(), // tenant queues; algorithm selects query component
-		}
+	algos := []tree.QueuingAlgorithm{
+		tree.NewQuerierWorkerQueuePriorityAlgo(), // root; algorithm selects query component based on worker ID
+		tqas.queuingAlgorithm,                    // query components; algorithm selects tenants
 	}
 	treeQueue, err = tree.NewTree(algos...)
 
@@ -66,11 +55,10 @@ func newQueueBroker(
 		panic(fmt.Sprintf("error creating the tree queue: %v", err))
 	}
 	qb := &queueBroker{
-		tree:                      treeQueue,
-		querierConnections:        qc,
-		tenantQuerierAssignments:  tqas,
-		maxTenantQueueSize:        maxTenantQueueSize,
-		prioritizeQueryComponents: prioritizeQueryComponents,
+		tree:                     treeQueue,
+		querierConnections:       qc,
+		tenantQuerierAssignments: tqas,
+		maxTenantQueueSize:       maxTenantQueueSize,
 	}
 
 	return qb
@@ -128,10 +116,7 @@ func (qb *queueBroker) makeQueuePath(request *tenantRequest) (tree.QueuePath, er
 	if schedulerRequest, ok := request.req.(*SchedulerRequest); ok {
 		queryComponent = schedulerRequest.ExpectedQueryComponentName()
 	}
-	if qb.prioritizeQueryComponents {
-		return append([]string{queryComponent}, request.tenantID), nil
-	}
-	return append(tree.QueuePath{request.tenantID}, queryComponent), nil
+	return append([]string{queryComponent}, request.tenantID), nil
 }
 
 func (qb *queueBroker) dequeueRequestForQuerier(