Imgo

Imgo is a distributed and high performance push server written in golang based on goim. compared to goim,it added offline message support,add will support IM server later on.

Features

Light weight and high performance

Supports single push, multiple push and broadcasting

Supports one key to multiple subscribers (Configurable maximum subscribers count)

Supports authentication (Unauthenticated user can't subscribe)

Supports multiple protocols (WebSocket，TCP)

Supports offline message (you can push even if user is not online)

Scalable architecture (Unlimited dynamic comet,logic,router,job modules)

Asynchronous push notification based on Kafka

Architecture

Client connect to server:

A client wants to subscribe a channel on comet through tcp or websocket,comet tells logic: "Here comes a guy,shall I keep a connection with him ?".

Logic take the token from comet and showed it to store: "Is this token valid? If it is,tell me the user id".

Logic got the user id,told router this user is online and keeps a connection with that comet,and told comet:"yes, you shall".

Then comet keeps connect to that client,and matains a heartbeat with him.

Logic knowed that comet and client was keep a connection, he ask store:"Is there any offline message of that user ?","yes,three of it",store answered and gave these to logic.

Logic packed the message into an envelope and thrown to kafka.

Job found a new envelope in kafka,fetch it and read the address:"comet 1,user 123456",then he told comet 1:"tell this to user 123456".

At last,comet told this message to user 123456.

Server push message to client:

Caller(usually a bussiness system) tells logic:"I want to send hello to a person,his user id is 123456".

Logic got the user id,ask router:"Is user 123456 online ?","yes,he is keeping a connection with comet 1" router replied.

Logic packed the message into an envelope and thrown to kafka.

Job found a new envelope in kafka,fetch it and read the address:"comet 1,user 123456",then he told comet 1:"tell this to user 123456".

At last,Comet told this message to user 123456.

Protocol:

Document

Examples

Java: Java

Benchmark

Benchmark Server

CPU

Memory

OS

Instance

Intel(R) Xeon(R) CPU E5-2630 v2 @ 2.60GHz

DDR3 32GB

Debian GNU/Linux 8

1

Benchmark Case

Online: 1,000,000

Duration: 15min

Push Speed: 40/s (broadcast room)

Push Message: {"test":1}

Received calc mode: 1s per times, total 30 times

Benchmark Resource

CPU: 2000%~2300%

Memory: 14GB

GC Pause: 504ms

Network: Incoming(450MBit/s), Outgoing(4.39GBit/s)

Benchmark Result

Received: 35,900,000/s

LICENSE

imgo is is distributed under the terms of the MIT License.