throttle

package
v0.16.0 Latest Latest
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 Go to latest Published: Feb 28, 2023 License: Apache-2.0 Imports: 31 Imported by: 0

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Index

Constants

View Source 
const (
	// DefaultAppName is the app name used by vitess when app doesn't indicate its name
	DefaultAppName = "default"
)

Variables

View Source 
var (
	ErrThrottlerNotReady = errors.New("throttler not enabled/ready")
)
View Source 
var NoSuchMetricCheckResult = NewErrorCheckResult(http.StatusNotFound, base.ErrNoSuchMetric)

NoSuchMetricCheckResult is a result returns when a metric is unknown

View Source 
var StandardCheckFlags = &CheckFlags{}

StandardCheckFlags have no special hints

Functions

This section is empty.

Types

type CheckFlags 

type CheckFlags struct {
	ReadCheck             bool
	OverrideThreshold     float64
	LowPriority           bool
	OKIfNotExists         bool
	SkipRequestHeartbeats bool
}

CheckFlags provide hints for a check

type CheckResult 

type CheckResult struct {
	StatusCode int     `json:"StatusCode"`
	Value      float64 `json:"Value"`
	Threshold  float64 `json:"Threshold"`
	Error      error   `json:"-"`
	Message    string  `json:"Message"`
}

CheckResult is the result for an app inquiring on a metric. It also exports as JSON via the API

func NewCheckResult 

func NewCheckResult(statusCode int, value float64, threshold float64, err error) *CheckResult

NewCheckResult returns a CheckResult

func NewErrorCheckResult 

func NewErrorCheckResult(statusCode int, err error) *CheckResult

NewErrorCheckResult returns a check result that indicates an error

type Client added in v0.10.0 

type Client struct {
	// contains filtered or unexported fields
}

Client construct is used by apps who wish to consult with a throttler. It encapsulates the check/throttling/backoff logic

func NewBackgroundClient added in v0.10.0 

func NewBackgroundClient(throttler *Throttler, appName string, checkType ThrottleCheckType) *Client

NewBackgroundClient creates a client suitable for background jobs, which have low priority over productio ntraffic, e.g. migration, table pruning, vreplication

func NewProductionClient added in v0.10.0 

func NewProductionClient(throttler *Throttler, appName string, checkType ThrottleCheckType) *Client

NewProductionClient creates a client suitable for foreground/production jobs, which have normal priority.

func (*Client) Throttle added in v0.10.0 

func (c *Client) Throttle(ctx context.Context)

Throttle throttles until the throttler is satisfied, or until context is cancelled. The function sleeps between throttle checks. The function is not thread safe.

func (*Client) ThrottleCheckOK added in v0.10.0 

func (c *Client) ThrottleCheckOK(ctx context.Context, overrideAppName string) (throttleCheckOK bool)

ThrottleCheckOK checks the throttler, and returns 'true' when the throttler is satisfied. It does not sleep. The function caches results for a brief amount of time, hence it's safe and efficient to be called very frequenty. The function is not thread safe.

func (*Client) ThrottleCheckOKOrWait added in v0.10.0 

func (c *Client) ThrottleCheckOKOrWait(ctx context.Context) bool

ThrottleCheckOKOrWait checks the throttler; if throttler is satisfied, the function returns 'true' mmediately, otherwise it briefly sleeps and returns 'false'. The function is not thread safe.

func (*Client) ThrottleCheckOKOrWaitAppName added in v0.14.0 

func (c *Client) ThrottleCheckOKOrWaitAppName(ctx context.Context, appName string) bool

ThrottleCheckOKOrWait checks the throttler; if throttler is satisfied, the function returns 'true' mmediately, otherwise it briefly sleeps and returns 'false'. Non-empty appName overrides the default appName. The function is not thread safe.

type ThrottleCheckType added in v0.10.0 

type ThrottleCheckType int // nolint:revive

ThrottleCheckType allows a client to indicate what type of check it wants to issue. See available types below. 

const (
	// ThrottleCheckPrimaryWrite indicates a check before making a write on a primary server
	ThrottleCheckPrimaryWrite ThrottleCheckType = iota
	// ThrottleCheckSelf indicates a check on a specific server health
	ThrottleCheckSelf
)

type Throttler 

type Throttler struct {
	MetricsThreshold sync2.AtomicFloat64
	// contains filtered or unexported fields
}

Throttler is the main entity in the throttling mechanism. This service runs, probes, collects data, aggregates, reads inventory, provides information, etc.

func NewThrottler 

func NewThrottler(env tabletenv.Env, srvTopoServer srvtopo.Server, ts *topo.Server, cell string, heartbeatWriter heartbeat.HeartbeatWriter, tabletTypeFunc func() topodatapb.TabletType) *Throttler

NewThrottler creates a Throttler

func (*Throttler) AppRequestMetricResult 

func (throttler *Throttler) AppRequestMetricResult(ctx context.Context, appName string, metricResultFunc base.MetricResultFunc, denyApp bool) (metricResult base.MetricResult, threshold float64)

AppRequestMetricResult gets a metric result in the context of a specific app

func (*Throttler) CheckByType added in v0.10.0 

func (throttler *Throttler) CheckByType(ctx context.Context, appName string, remoteAddr string, flags *CheckFlags, checkType ThrottleCheckType) (checkResult *CheckResult)

CheckByType runs a check by requested check type

func (*Throttler) CheckIsReady added in v0.14.0 

func (throttler *Throttler) CheckIsReady() error

CheckIsReady checks if this throttler is ready to serve. If not, it returns an error

func (*Throttler) Close 

func (throttler *Throttler) Close()

Close frees resources

func (*Throttler) Disable added in v0.16.0 

func (throttler *Throttler) Disable(ctx context.Context) bool

Disable deactivates the probes and associated operations. When disabled, the throttler reponds to check queries with "200 OK" irrespective of lag or any other metrics.

func (*Throttler) Enable added in v0.16.0 

func (throttler *Throttler) Enable(ctx context.Context) bool

Enable activates the throttler probes; when enabled, the throttler responds to check queries based on the collected metrics.

func (*Throttler) GetMetricsQuery added in v0.16.0 

func (throttler *Throttler) GetMetricsQuery() string

func (*Throttler) InitDBConfig 

func (throttler *Throttler) InitDBConfig(keyspace, shard string)

InitDBConfig initializes keyspace and shard

func (*Throttler) IsAppThrottled 

func (throttler *Throttler) IsAppThrottled(appName string) bool

IsAppThrottled tells whether some app should be throttled. Assuming an app is throttled to some extend, it will randomize the result based on the throttle ratio

func (*Throttler) IsEnabled added in v0.16.0 

func (throttler *Throttler) IsEnabled() bool

func (*Throttler) Open 

func (throttler *Throttler) Open() error

Open opens database pool and initializes the schema

func (*Throttler) Operate 

func (throttler *Throttler) Operate(ctx context.Context)

Operate is the main entry point for the throttler operation and logic. It will run the probes, colelct metrics, refresh inventory, etc.

func (*Throttler) RecentAppsMap 

func (throttler *Throttler) RecentAppsMap() (result map[string](*base.RecentApp))

RecentAppsMap returns a (copy) map of apps which checked for throttling recently

func (*Throttler) Status 

func (throttler *Throttler) Status() *ThrottlerStatus

Status exports a status breakdown

func (*Throttler) ThrottleApp 

func (throttler *Throttler) ThrottleApp(appName string, expireAt time.Time, ratio float64) (appThrottle *base.AppThrottle)

ThrottleApp instructs the throttler to begin throttling an app, to som eperiod and with some ratio.

func (*Throttler) ThrottledApps added in v0.14.0 

func (throttler *Throttler) ThrottledApps() (result []base.AppThrottle)

ThrottledAppsSnapshot returns a snapshot (a copy) of current throttled apps

func (*Throttler) ThrottledAppsMap 

func (throttler *Throttler) ThrottledAppsMap() (result map[string](*base.AppThrottle))

ThrottledAppsMap returns a (copy) map of currently throttled apps

func (*Throttler) UnthrottleApp 

func (throttler *Throttler) UnthrottleApp(appName string) (appThrottle *base.AppThrottle)

UnthrottleApp cancels any throttling, if any, for a given app

func (*Throttler) WatchSrvKeyspaceCallback added in v0.16.0 

func (throttler *Throttler) WatchSrvKeyspaceCallback(srvks *topodatapb.SrvKeyspace, err error) bool

WatchSrvKeyspaceCallback gets called whenever SrvKeyspace has been modified. This callback only examines the ThrottlerConfig part of SrvKeyspace, and proceeds to inform the throttler of the new config

type ThrottlerCheck 

type ThrottlerCheck struct {
	// contains filtered or unexported fields
}

ThrottlerCheck provides methods for an app checking on metrics

func NewThrottlerCheck 

func NewThrottlerCheck(throttler *Throttler) *ThrottlerCheck

NewThrottlerCheck creates a ThrottlerCheck

func (*ThrottlerCheck) AggregatedMetrics 

func (check *ThrottlerCheck) AggregatedMetrics(ctx context.Context) map[string]base.MetricResult

AggregatedMetrics is a convenience access method into throttler's `aggregatedMetricsSnapshot`

func (*ThrottlerCheck) Check 

func (check *ThrottlerCheck) Check(ctx context.Context, appName string, storeType string, storeName string, remoteAddr string, flags *CheckFlags) (checkResult *CheckResult)

Check is the core function that runs when a user wants to check a metric

func (*ThrottlerCheck) MetricsHealth 

func (check *ThrottlerCheck) MetricsHealth() map[string](*base.MetricHealth)

MetricsHealth is a convenience access method into throttler's `metricsHealthSnapshot`

func (*ThrottlerCheck) SelfChecks 

func (check *ThrottlerCheck) SelfChecks(ctx context.Context)

SelfChecks runs checks on all known metrics as if we were an app. This runs asynchronously, continuously, and independently of any user interaction

type ThrottlerStatus 

type ThrottlerStatus struct {
	Keyspace string
	Shard    string

	IsLeader  bool
	IsOpen    bool
	IsDormant bool

	AggregatedMetrics map[string]base.MetricResult
	MetricsHealth     base.MetricHealthMap
}

ThrottlerStatus published some status values from the throttler

Source Files

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