pool

Documentation

Index

• Constants
• Variables
• func Dial(address string) (*grpc.ClientConn, error)
• type Conn
• type Option
  • func WithDial(dial func(address string) (*grpc.ClientConn, error)) Option
• type Pool
  • func New(address string, opt ...Option) (Pool, error)

Constants

const (
	// DialTimeout the timeout of create connection
	DialTimeout = 5 * time.Second

	// BackoffMaxDelay provided maximum delay when backing off after failed connection attempts.
	BackoffMaxDelay = 3 * time.Second

	// KeepAliveTime is the duration of time after which if the client doesn't see
	// any activity it pings the server to see if the transport is still alive.
	KeepAliveTime = time.Duration(10) * time.Second

	// KeepAliveTimeout is the duration of time for which the client waits after having
	// pinged for keepalive check and if no activity is seen even after that the connection
	// is closed.
	KeepAliveTimeout = time.Duration(3) * time.Second

	// InitialWindowSize we set it 1GB is to provide system's throughput.
	InitialWindowSize = 1 << 30

	// InitialConnWindowSize we set it 1GB is to provide system's throughput.
	InitialConnWindowSize = 1 << 30

	// MaxSendMsgSize set max gRPC request message size sent to server.
	// If any request message size is larger than current value, an error will be reported from gRPC.
	MaxSendMsgSize = 4 << 30

	// MaxRecvMsgSize set max gRPC receive message size received from server.
	// If any message size is larger than current value, an error will be reported from gRPC.
	MaxRecvMsgSize = 4 << 30
)

Variables

var DefaultOptions = options{
	Dial:                 Dial,
	MaxIdle:              4,
	MaxActive:            16,
	MaxConcurrentStreams: 16,
	Reuse:                true,
}

DefaultOptions sets a list of recommended options for good performance. Feel free to modify these to suit your needs.

var ErrClosed = errors.New("pool is closed")

ErrClosed is the error resulting if the pool is closed via pool.Close().

Functions

func Dial

func Dial(address string) (*grpc.ClientConn, error)

Dial return a grpc connection with defined configurations.

Types

type Conn

type Conn interface {
	// Value return the actual grpc connection type *grpc.ClientConn.
	Value() *grpc.ClientConn

	// Close decrease the reference of grpc connection, instead of close it.
	// if the pool is full, just close it.
	Close() error
}

type Option

type Option func(o *options)

func WithDial

func WithDial(dial func(address string) (*grpc.ClientConn, error)) Option

type Pool

type Pool interface {
	// Get returns a new connection from the pool. Closing the connections puts
	// it back to the Pool. Closing it when the pool is destroyed or full will
	// be counted as an error. we guarantee the conn.Value() isn't nil when conn isn't nil.
	Get() (Conn, error)

	// Close closes the pool and all its connections. After Close() the pool is
	// no longer usable. You can't make concurrent calls Close and Get method.
	// It will be cause panic.
	Close() error

	// Status returns the current status of the pool.
	Status() string
}

func New

func New(address string, opt ...Option) (Pool, error)

New return a connection pool.