drpc

README

A drop-in, lightweight gRPC replacement.

Links

• DRPC website
• Examples
• Quickstart documentation
• Launch blog post

Highlights

• Simple, at just a few thousand lines of code.
• Small dependencies. Only 3 requirements in go.mod, and 9 lines of go mod graph!
• Compatible. Works for many gRPC use-cases as-is!
• Fast. DRPC has a lightning quick wire format.
• Extensible. DRPC is transport agnostic, supports middleware, and is designed around interfaces.
• Battle Tested. Already used in production for years across tens of thousands of servers.

External Packages

• go.bryk.io/pkg/net/drpc

  • Simplified TLS setup (for client and server)
  • Server middleware, including basic components for logging, token-based auth, rate limit, panic recovery, etc
  • Client middleware, including basic components for logging, custom metadata, panic recovery, etc
  • Bi-directional streaming support over upgraded HTTP(S) connections using WebSockets
  • Concurrent RPCs via connection pool

• Open an issue or join the Zulip chat if you'd like to be featured here.

Other Languages

DRPC can be made compatible with RPC clients generated from other languages. For example, Twirp clients and grpc-web clients can be used against the drpchttp package.

Native implementations can have some advantages, and so some bindings for other languages are in progress, all in various states of completeness. Join the Zulip chat if you want more information or to help out with any!

Language	Repository	Status
C++	https://github.com/storj/drpc-cpp	Incomplete
Rust	https://github.com/zeebo/drpc-rs	Incomplete
Node	https://github.com/mjpitz/drpc-node	Incomplete

Licensing

DRPC is licensed under the MIT/expat license. See the LICENSE file for more.

---

Benchmarks

These microbenchmarks attempt to provide a comparison and come with some caveats. First, it does not send data over a network connection which is expected to be the bottleneck almost all of the time. Second, no attempt was made to do the benchmarks in a controlled environment (CPU scaling disabled, noiseless, etc.). Third, no tuning was done to ensure they're both performing optimally, so there is an inherent advantage for DRPC because the author is familiar with how it works.

Measure

Benchmark

Small

Medium

Large

gRPC

DRPC

delta

gRPC

DRPC

delta

gRPC

DRPC

delta

time/op

Unitary

30.2µs

8.6µs

-71.60%

38.0µs

11.1µs

-70.88%

1.33ms

0.63ms

-52.30%

Input Stream

878ns

759ns

-13.54%

2.85µs

2.00µs

-29.69%

508µs

249µs

-51.08%

Output Stream

862ns

757ns

-12.18%

2.76µs

1.99µs

-27.92%

487µs

239µs

-50.94%

Bidir Stream

9.81µs

3.30µs

-66.38%

14.8µs

4.9µs

-66.69%

1.31ms

0.55ms

-58.41%

speed

Unitary

70.0kB/s

230.0kB/s

+228.57%

54.0MB/s

185.3MB/s

+243.44%

791MB/s

1658MB/s

+109.62%

Input Stream

2.29MB/s

2.64MB/s

+15.37%

721MB/s

1026MB/s

+42.21%

2.06GB/s

4.22GB/s

+104.32%

Output Stream

2.32MB/s

2.64MB/s

+13.67%

743MB/s

1031MB/s

+38.74%

2.15GB/s

4.39GB/s

+103.75%

Bidir Stream

200kB/s

604kB/s

+201.87%

138MB/s

415MB/s

+200.20%

799MB/s

1920MB/s

+140.44%

mem/op

Unitary

8.37kB

1.29kB

-84.59%

21.8kB

7.7kB

-64.81%

6.50MB

3.16MB

-51.38%

Input Stream

399B

80B

-79.96%

7.09kB

2.13kB

-69.97%

3.20MB

1.05MB

-67.16%

Output Stream

309B

80B

-74.13%

6.98kB

2.13kB

-69.53%

3.20MB

1.05MB

-67.17%

Bidir Stream

1.02kB

0.24kB

-76.40%

14.4kB

4.3kB

-69.99%

6.52MB

2.10MB

-67.74%

allocs/op

Unitary

169

7

-95.86%

171

9

-94.74%

403

9

-97.76%

Input Stream

11

1

-90.91%

12

2

-83.33%

121

2

-98.35%

Output Stream

9

1

-88.89%

10

2

-80.00%

117

2

-98.29%

Bidir Stream

41

3

-92.68%

44

5

-88.64%

272

5

-98.16%

Lines of code

Package	Lines
storj.io/drpc/drpchttp	475
storj.io/drpc/cmd/protoc-gen-go-drpc	418
storj.io/drpc/drpcstream	390
storj.io/drpc/drpcwire	332
storj.io/drpc/drpcmanager	300
storj.io/drpc/drpcmigrate	237
storj.io/drpc/drpcsignal	133
storj.io/drpc/drpcconn	116
storj.io/drpc/drpcmetadata	115
storj.io/drpc/drpcmux	95
storj.io/drpc/drpcserver	76
storj.io/drpc/drpccache	54
storj.io/drpc	47
storj.io/drpc/drpcerr	42
storj.io/drpc/drpcctx	37
storj.io/drpc/drpcdebug	22
storj.io/drpc/drpcenc	15
storj.io/drpc/internal/drpcopts	11
Total	2915

Documentation

Overview

Package drpc is a light replacement for gprc.

Index

• Variables
• type Conn
• type Description
• type Encoding
• type Handler
• type Message
• type Mux
• type Receiver
• type Stream
• type Transport

Variables

var (
	Error         = errs.Class("drpc")
	InternalError = errs.Class("internal error")
	ProtocolError = errs.Class("protocol error")
	ClosedError   = errs.Class("closed")
)

These error classes represent some common errors that drpc generates.

Types

type Conn

type Conn interface {
	// Close closes the connection.
	Close() error

	// Closed returns a channel that is closed if the connection is definitely closed.
	Closed() <-chan struct{}

	// Invoke issues a unary RPC to the remote. Only one Invoke or Stream may be
	// open at once.
	Invoke(ctx context.Context, rpc string, enc Encoding, in, out Message) error

	// NewStream starts a stream with the remote. Only one Invoke or Stream may be
	// open at once.
	NewStream(ctx context.Context, rpc string, enc Encoding) (Stream, error)
}

Conn represents a client connection to a server.

type Description

type Description interface {
	// NumMethods returns the number of methods available.
	NumMethods() int

	// Method returns the information about the nth method along with a handler
	// to invoke it. The method interface that it returns is expected to be
	// a method expression like `(*Type).HandlerName`.
	Method(n int) (rpc string, encoding Encoding, receiver Receiver, method interface{}, ok bool)
}

Description is the interface implemented by things that can be registered by a Server.

type Encoding

type Encoding interface {
	// Marshal returns the encoded form of msg.
	Marshal(msg Message) ([]byte, error)

	// Unmarshal reads the encoded form of some Message into msg.
	// The buf is expected to contain only a single complete Message.
	Unmarshal(buf []byte, msg Message) error
}

Encoding represents a way to marshal/unmarshal Message types.

type Handler

type Handler interface {
	// HandleRPC executes the RPC identified by the rpc string using the stream to
	// communicate with the remote.
	HandleRPC(stream Stream, rpc string) (err error)
}

Handler handles streams and RPCs dispatched to it by a Server.

type Message

type Message interface{}

Message is a protobuf message. It is expected to be used with an Encoding. This exists so that one can use whatever protobuf library/runtime they want.

type Mux

type Mux interface {
	// Register marks that the description should dispatch RPCs that it describes to
	// the provided srv.
	Register(srv interface{}, desc Description) error
}

Mux is a type that can have an implementation and a Description registered with it.

type Receiver

type Receiver = func(srv interface{}, ctx context.Context, in1, in2 interface{}) (out Message, err error)

Receiver is invoked by a server for a given RPC.

type Stream

type Stream interface {
	// Context returns the context associated with the stream. It is canceled
	// when the Stream is closed and no more messages will ever be sent or
	// received on it.
	Context() context.Context

	// MsgSend sends the Message to the remote.
	MsgSend(msg Message, enc Encoding) error

	// MsgRecv receives a Message from the remote.
	MsgRecv(msg Message, enc Encoding) error

	// CloseSend signals to the remote that we will no longer send any messages.
	CloseSend() error

	// Close closes the stream.
	Close() error
}

Stream is a bi-directional stream of messages to some other party.

type Transport

type Transport interface {
	io.Reader
	io.Writer
	io.Closer
}

Transport is an interface describing what is required for a drpc connection. Any net.Conn can be used as a Transport.