loadtester

package
v5.0.5 Latest Latest
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 Go to latest Published: Aug 23, 2025 License: MIT Imports: 20 Imported by: 0

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Index

Constants

This section is empty.

Variables

View Source 
var (
	ErrBadReadTasksImpl     = errors.New("bad ReadTasks implementation: returned a value less than zero or larger than the input slice length")
	ErrRetriesFailedToFlush = errors.New("failed to flush all retries")
)

Functions

func GetTaskMetadataProvider added in v5.0.1 

func GetTaskMetadataProvider(ctx context.Context) *taskMetadata

GetTaskMetadataProvider returns a possibly nil value that implements:

- `IntervalID() time.Time`

- `EnqueueTime() time.Time`

- `DequeueTime() time.Time`

- `SampleSize() int`

- `NumIntervalTasks() int`

- `Lag() time.Duration`

func NewLogger 

func NewLogger(level slog.Level) (*slog.Logger, error)

NewLogger should likely be followed by a call to slog.SetDefault with the logger returned by this function if called in the program's main context.

func RootContext 

func RootContext(logger StructuredLogger) (context.Context, func())

RootContext returns a context that is canceled when the system process receives an interrupt, sigint, or sigterm

Also returns a function that can be used to cancel the context.

Types

type ConfigUpdate 

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

func (*ConfigUpdate) SetInterval 

func (cu *ConfigUpdate) SetInterval(d time.Duration)

func (*ConfigUpdate) SetNumIntervalTasks 

func (cu *ConfigUpdate) SetNumIntervalTasks(n int)

func (*ConfigUpdate) SetNumWorkers 

func (cu *ConfigUpdate) SetNumWorkers(n int)

type DoRetryChecker 

type DoRetryChecker interface {
	DoRetryer
	RetryChecker
}

type DoRetryer 

type DoRetryer interface {
	Doer
	Retryer
}

DoRetryer interface is useful for tasks that have no retry count upper bound

If you need to have a retry upper bound, then have your task implement DoRetryChecker

type Doer 

type Doer interface {
	Do(ctx context.Context, workerID int) error
}

Doer is a basic task unit

If your Doer also implements Retryer then note that Doer can be run again in a different thread if your worker size is greater than one.

If you want your task to have a retry upper bound then implement DoRetryChecker

type Loadtest 

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

func NewLoadtest 

func NewLoadtest(options ...LoadtestOption) (*Loadtest, error)

func (*Loadtest) NewHttpTransport 

func (lt *Loadtest) NewHttpTransport() *http.Transport

HttpTransport returns a new configured *http.Transport which implements http.RoundTripper that can be used in tasks which have http clients

Note, you may need to increase the value of MaxIdleConns if your tasks target multiple hosts. MaxIdleConnsPerHost does not override the limit established by MaxIdleConns and if the tasks are expected to communicate to multiple hosts you probably need to apply some scaling factor to it to let connections go idle for a time and still be reusable.

Note that if you are not connecting to a load balancer which preserves connections to a client much of the intent we're trying to establish here is not applicable.

Also if the load balancer does not have "max connection lifespan" behavior nor a "round robin" or "connection balancing" feature without forcing the loadtesting client to reconnect then as you increase load your established connections may prevent the spread of load to newly scaled-out recipients of that load.

By default golang's http standard lib does not expose a way for us to attempt to address this. The problem is also worse if your load balancer ( or number of exposed ips for a dns record ) increase.

Rectifying this issue requires a fix like/option like https://github.com/golang/go/pull/46714 to be accepted by the go maintainers.

func (*Loadtest) Run 

func (lt *Loadtest) Run(ctx context.Context) (err_result error)

Run can only be called once per loadtest instance, it is stateful

func (*Loadtest) UpdateConfig 

func (lt *Loadtest) UpdateConfig(cu ConfigUpdate) (handled bool)

UpdateConfig only returns false if the loadtest's run method has exited

This call can potentially block the caller on loadtest shutdown phase.

type LoadtestOption 

type LoadtestOption func(*loadtestConfig)

type LoadtestOptions added in v5.0.3 

type LoadtestOptions struct{}

LoadtestOptions should never be instantiated manually

Instead call NewOpts()

This is only exported to allow godocs to discover the exported methods.

LoadtestOptions will never have exported data members, just stateless exported functions.

func NewOpts 

func NewOpts() LoadtestOptions

func (LoadtestOptions) FlushRetriesOnShutdown added in v5.0.3 

func (LoadtestOptions) FlushRetriesOnShutdown(b bool) LoadtestOption

FlushRetriesOnShutdown is useful when your loadtest is more like a smoke test that must have all tasks flush and be successful

func (LoadtestOptions) FlushRetriesTimeout added in v5.0.3 

func (LoadtestOptions) FlushRetriesTimeout(d time.Duration) LoadtestOption

FlushRetriesTimeout is only relevant when FlushRetriesOnShutdown(true) is used

func (LoadtestOptions) Interval added in v5.0.3 

func (LoadtestOptions) Interval(d time.Duration) LoadtestOption

func (LoadtestOptions) Logger added in v5.0.3 

func (LoadtestOptions) Logger(logger StructuredLogger) LoadtestOption

func (LoadtestOptions) MaxIntervalTasks added in v5.0.3 

func (LoadtestOptions) MaxIntervalTasks(n int) LoadtestOption

func (LoadtestOptions) MaxTasks added in v5.0.3 

func (LoadtestOptions) MaxTasks(max int) LoadtestOption

MaxTasks sets an upper bound on the number of tasks the loadtest could perform

func (LoadtestOptions) MaxWorkers added in v5.0.3 

func (LoadtestOptions) MaxWorkers(max int) LoadtestOption

func (LoadtestOptions) MetadataProviderEnabled added in v5.0.3 

func (LoadtestOptions) MetadataProviderEnabled(b bool) LoadtestOption

MetadataProviderEnabled sets wether the context provided to a task's Do, CanRetry, and Retry methods returns a non-nil value when passed to GetTaskMetadataProvider(...)

Use GetTaskMetadataProvider to instrument result reporting as you may see fit with far more granularity than the high level metrics.csv.

off == false (default)

func (LoadtestOptions) MetricsCsv added in v5.0.3 

func (LoadtestOptions) MetricsCsv(b bool) LoadtestOption

func (LoadtestOptions) MetricsCsvFilename added in v5.0.3 

func (LoadtestOptions) MetricsCsvFilename(s string) LoadtestOption

func (LoadtestOptions) MetricsCsvFlushInterval added in v5.0.3 

func (LoadtestOptions) MetricsCsvFlushInterval(d time.Duration) LoadtestOption

func (LoadtestOptions) MetricsLatencyPercentile added in v5.0.3 

func (LoadtestOptions) MetricsLatencyPercentile(b bool) LoadtestOption

MetricsLatencyPercentile can greatly increase the amount of memory used and create additional delay while processing results.

Make sure MaxIntervalTasks is either not set or if it must be set make sure it is not too large for the hosts's ram availability.

func (LoadtestOptions) MetricsLatencyVariance added in v5.0.3 

func (LoadtestOptions) MetricsLatencyVariance(b bool) LoadtestOption

MetricsLatencyVariance can create additional delay while processing results.

func (LoadtestOptions) NumIntervalTasks added in v5.0.3 

func (LoadtestOptions) NumIntervalTasks(n int) LoadtestOption

func (LoadtestOptions) NumWorkers added in v5.0.3 

func (LoadtestOptions) NumWorkers(n int) LoadtestOption

func (LoadtestOptions) OutputBufferingFactor added in v5.0.3 

func (LoadtestOptions) OutputBufferingFactor(factor int) LoadtestOption

func (LoadtestOptions) Retry added in v5.0.3 

func (LoadtestOptions) Retry(b bool) LoadtestOption

Retry sets wether the loadtester has retry support on or off.

on == true (default)

func (LoadtestOptions) TaskReader added in v5.0.3 

func (LoadtestOptions) TaskReader(taskReader TaskReader) LoadtestOption

type RetryChecker 

type RetryChecker interface {
	CanRetry(ctx context.Context, workerID int, prevErr error) bool
}

type Retryer 

type Retryer interface {
	Retry(ctx context.Context, workerID int, prevErr error) error
}

type StructuredLogger 

type StructuredLogger interface {
	LogAttrs(ctx context.Context, level slog.Level, msg string, attrs ...slog.Attr)
}

type TaskReader 

type TaskReader interface {
	// ReadTasks fills the provided slice up to slice length starting at index 0 and returns how many records have been inserted
	//
	// Failing to fill the whole slice will signal the end of the loadtest.
	//
	// Note in general you should not use this behavior to signal loadtests to stop
	// if your loadtest needs to be time-bound. For that case you should signal a stop
	// via the context. This stop on failure to fill behavior only exists for cases
	// where the author wants to exhaustively run a set of tasks and not bound the
	// loadtest to a timespan but rather completeness of the tasks space.
	//
	// Note that if you have only partially filled the slice, those filled task slots
	// will still be run before termination of the loadtest.
	//
	// It is important to remember that if your loadtest loops around and you keep a large slice of
	// tasks in memory just to place small chunks of that list into the passed in slice of this function
	// that you could have a task executed by two separate goroutines at the same time under the right circumstances.
	// Therefore, it's really important that the tasks either be stateless or concrete copies of the original task object are
	// created when saved to the passed in slice of this function.
	ReadTasks([]Doer) int
}

TaskReader describes how to read tasks into a loadtest

Source Files

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Directories

Path Synopsis
internal
cmd/generate command

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