queuelistener

Documentation

Index

• func Listen(o Options) (net.Listener, error)
• type Options

Functions

func Listen

func Listen(o Options) (net.Listener, error)

Listen creates and initializes a listener that can be used to limit the concurrently accepted incoming client connections.

The queue listener will return only a limited number of concurrent connections by its Accept() method, defined by the max concurrency configuration. When the max concurrency is reached, the Accept() method will block until one or more accepted connections are closed. When the max concurrency limit is reached, the new incoming client connections are stored in a queue. When an active (accepted) connection is closed, the listener will return the most recent one from the queue (LIFO). When the queue is full, the oldest pending connection is closed and dropped, and the new one is inserted into the queue.

The listener needs to be closed in order to release local resources. After it is closed, Accept() returns an error without blocking.

See type Options for info about the configuration of the listener.

Types

type Options

type Options struct {

	// Network sets the name of the network. Same as for net.Listen().
	Network string

	// Address sets the listener address, e.g. :9090. Same as for net.Listen().
	Address string

	// MaxConcurrency sets the maximum accepted connections.
	MaxConcurrency int

	// MaxQueue size sets the maximum allowed queue size of pending connections. When
	// not set, it is derived from the MaxConcurrency value.
	MaxQueueSize int

	// MemoryLimitBytes sets the approximated maximum memory used by the accepted
	// connections, calculated together with the ConnectionBytes value. Defaults to
	// 150MB.
	//
	// When MaxConcurrency is set, this field is ignored.
	MemoryLimitBytes int64

	// ConnectionBytes is used to calculate the MaxConcurrency when MaxConcurrency is
	// not set explicitly but calculated from MemoryLimitBytes.
	ConnectionBytes int

	// QueueTimeout set the time limit for pending connections spent in the queue. It
	// should be set to a similar value as the ReadHeaderTimeout of net/http.Server.
	QueueTimeout time.Duration

	// Metrics is used to collect monitoring data about the queue, including the current
	// concurrent connections and the number of connections in the queue.
	Metrics metrics.Metrics

	// Log is used to log unexpected, non-fatal errors. It defaults to logging.DefaultLog.
	Log logging.Logger
	// contains filtered or unexported fields
}

Options are used to initialize the queue listener.