Files
tasks/service/history/queue_factory_base.go
Yaniv KaulandGitHub f21f980acf fix: avoid zero-rate queue reader throttling (#9619)
## Summary
- When `persistenceMaxQPS` is set to `0` (meaning "unlimited"), the
queue reader rate limiter receives a zero rate, causing all queue
readers to fail with "burst size is smaller than required token count"
and never process tasks.
- This fixes the rate function to return a high default (100,000) when
persistence QPS is unlimited, and adds a missing `return` after the
error log to prevent falling through to an invalid lock/read path.

## Bug Details
`NewHostRateLimiterRateFn` computes `float64(persistenceMaxRPS()) *
persistenceMaxRPSRatio`. When `persistenceMaxRPS()` returns 0
(unlimited), this produces rate=0, which creates a rate limiter with
burst=0. The reader then cannot acquire even 1 token, logging the error
but continuing into `r.Lock()` without tasks — effectively a tight error
loop.

## Testing
- Verified with benchmarks that queue readers function correctly with
`persistenceMaxQPS: 0` in dynamic config.
- Existing unit tests pass.
2026-04-24 15:19:13 -07:00

243 lines
7.3 KiB
Go

package history
import (
"context"
"go.opentelemetry.io/otel/trace"
"go.temporal.io/server/chasm"
"go.temporal.io/server/common/clock"
"go.temporal.io/server/common/cluster"
"go.temporal.io/server/common/dynamicconfig"
"go.temporal.io/server/common/log"
"go.temporal.io/server/common/log/tag"
"go.temporal.io/server/common/membership"
"go.temporal.io/server/common/metrics"
"go.temporal.io/server/common/namespace"
"go.temporal.io/server/common/persistence"
"go.temporal.io/server/common/persistence/serialization"
"go.temporal.io/server/common/quotas"
"go.temporal.io/server/common/quotas/calculator"
"go.temporal.io/server/service/history/circuitbreakerpool"
"go.temporal.io/server/service/history/configs"
historyi "go.temporal.io/server/service/history/interfaces"
"go.temporal.io/server/service/history/queues"
"go.temporal.io/server/service/history/replication/eventhandler"
"go.temporal.io/server/service/history/shard"
"go.temporal.io/server/service/history/tasks"
wcache "go.temporal.io/server/service/history/workflow/cache"
"go.uber.org/fx"
)
const QueueFactoryFxGroup = "queueFactory"
type (
QueueFactory interface {
Start()
Stop()
// TODO: Move this interface to queues package
CreateQueue(shardContext historyi.ShardContext) queues.Queue
}
QueueFactoryBaseParams struct {
fx.In
NamespaceRegistry namespace.Registry
ClusterMetadata cluster.Metadata
WorkflowCache wcache.Cache
Config *configs.Config
TimeSource clock.TimeSource
MetricsHandler metrics.Handler
TracerProvider trace.TracerProvider
Logger log.SnTaggedLogger
SchedulerRateLimiter queues.SchedulerRateLimiter
DLQWriter *queues.DLQWriter
ExecutorWrapper queues.ExecutorWrapper `optional:"true"`
Serializer serialization.Serializer
RemoteHistoryFetcher eventhandler.HistoryPaginatedFetcher
ChasmEngine chasm.Engine
ChasmRegistry *chasm.Registry
}
QueueFactoryBase struct {
HostScheduler queues.Scheduler
HostPriorityAssigner queues.PriorityAssigner
HostReaderRateLimiter quotas.RequestRateLimiter
Tracer trace.Tracer
}
QueueFactoriesLifetimeHookParams struct {
fx.In
Lifecycle fx.Lifecycle
Factories []QueueFactory `group:"queueFactory"`
}
)
var QueueModule = fx.Options(
circuitbreakerpool.Module,
fx.Provide(
QueueSchedulerRateLimiterProvider,
func(tqm persistence.HistoryTaskQueueManager) queues.QueueWriter {
return tqm
},
queues.NewDLQWriter,
fx.Annotated{
Group: QueueFactoryFxGroup,
Target: NewTransferQueueFactory,
},
fx.Annotated{
Group: QueueFactoryFxGroup,
Target: NewTimerQueueFactory,
},
fx.Annotated{
Group: QueueFactoryFxGroup,
Target: NewVisibilityQueueFactory,
},
fx.Annotated{
Group: QueueFactoryFxGroup,
Target: NewMemoryScheduledQueueFactory,
},
getOptionalQueueFactories,
),
fx.Invoke(QueueFactoryLifetimeHooks),
)
// additionalQueueFactories is a container for a list of queue factories that are only added to the group if
// they are enabled. This exists because there is no way to conditionally add to a group with a provider that returns
// a single object. For example, this doesn't work because it will always add the factory to the group, which can
// cause NPEs:
//
// fx.Annotated{
// Group: "queueFactory",
// Target: func() QueueFactory { return isEnabled ? NewQueueFactory() : nil },
// },
type additionalQueueFactories struct {
// This is what tells fx to add the factories to the group whenever this object is provided.
fx.Out
// Factories is a list of queue factories that will be added to the `group:"queueFactory"` group.
Factories []QueueFactory `group:"queueFactory,flatten"`
}
// getOptionalQueueFactories returns an additionalQueueFactories which contains a list of queue factories that will be
// added to the `group:"queueFactory"` group. The factories are added to the group only if they are enabled, which
// is why we must return a list here.
func getOptionalQueueFactories(
registry tasks.TaskCategoryRegistry,
archivalParams ArchivalQueueFactoryParams,
outboundParams outboundQueueFactoryParams,
config *configs.Config,
) additionalQueueFactories {
factories := []QueueFactory{}
if _, ok := registry.GetCategoryByID(tasks.CategoryIDArchival); ok {
factories = append(factories, NewArchivalQueueFactory(archivalParams))
}
factories = append(factories, NewOutboundQueueFactory(outboundParams))
return additionalQueueFactories{
Factories: factories,
}
}
func QueueSchedulerRateLimiterProvider(
ownershipBasedQuotaScaler shard.LazyLoadedOwnershipBasedQuotaScaler,
serviceResolver membership.ServiceResolver,
config *configs.Config,
timeSource clock.TimeSource,
logger log.SnTaggedLogger,
) (queues.SchedulerRateLimiter, error) {
return queues.NewPrioritySchedulerRateLimiter(
calculator.NewLoggedNamespaceCalculator(
shard.NewOwnershipAwareNamespaceQuotaCalculator(
ownershipBasedQuotaScaler,
serviceResolver,
config.TaskSchedulerNamespaceMaxQPS,
config.TaskSchedulerGlobalNamespaceMaxQPS,
),
log.With(logger, tag.ComponentTaskScheduler, tag.ScopeNamespace),
).GetQuota,
calculator.NewLoggedCalculator(
shard.NewOwnershipAwareQuotaCalculator(
ownershipBasedQuotaScaler,
serviceResolver,
config.TaskSchedulerMaxQPS,
config.TaskSchedulerGlobalMaxQPS,
),
log.With(logger, tag.ComponentTaskScheduler, tag.ScopeHost),
).GetQuota,
// TODO: reuse persistence rate limit calculator in PersistenceRateLimitingParamsProvider
shard.NewOwnershipAwareNamespaceQuotaCalculator(
ownershipBasedQuotaScaler,
serviceResolver,
config.PersistenceNamespaceMaxQPS,
config.PersistenceGlobalNamespaceMaxQPS,
).GetQuota,
shard.NewOwnershipAwareQuotaCalculator(
ownershipBasedQuotaScaler,
serviceResolver,
config.PersistenceMaxQPS,
config.PersistenceGlobalMaxQPS,
).GetQuota,
)
}
func QueueFactoryLifetimeHooks(
params QueueFactoriesLifetimeHookParams,
) {
params.Lifecycle.Append(
fx.Hook{
OnStart: func(context.Context) error {
for _, factory := range params.Factories {
factory.Start()
}
return nil
},
OnStop: func(context.Context) error {
for _, factory := range params.Factories {
factory.Stop()
}
return nil
},
},
)
}
func (f *QueueFactoryBase) Start() {
if f.HostScheduler != nil {
f.HostScheduler.Start()
}
}
func (f *QueueFactoryBase) Stop() {
if f.HostScheduler != nil {
f.HostScheduler.Stop()
}
}
func NewHostRateLimiterRateFn(
hostRPS dynamicconfig.IntPropertyFn,
persistenceMaxRPS dynamicconfig.IntPropertyFn,
persistenceMaxRPSRatio float64,
) quotas.RateFn {
// TODO: reuse persistence rate limit calculator in PersistenceRateLimitingParamsProvider
return func() float64 {
if maxPollHostRps := hostRPS(); maxPollHostRps > 0 {
return float64(maxPollHostRps)
}
if pMaxRPS := persistenceMaxRPS(); pMaxRPS > 0 {
// ensure queue loading won't consume all persistence tokens
// especially upon host restart when we need to perform a load
// for all shards
return float64(pMaxRPS) * persistenceMaxRPSRatio
}
// persistenceMaxQPS=0 means "unlimited" — use a high default to avoid
// producing a zero rate which would block all queue readers.
// NOTE: Do not use math.MaxFloat64 here; int(math.MaxFloat64) overflows
// to math.MinInt64, which breaks burst calculation in the rate limiter.
return 100_000
}
}