The ActiveStack Gateway is a Node server that sets up a real-time socket server for clients wanting to connect to the ActiveStack backend.
- Node >= 0.10
- Redis
- RabbitMQ
The AS Gateway provides two usage methods:
- Install globally with NPM:
npm install -g activestack-gateway
. This method will make theactivestack-gateway
executable available on your path for starting from the command line. - Install in your own node project with
npm install activestack-gateway
. This method will make the gateway available to your project at runtime so you can control the gateway from your application.
If you installed the gateway with the global option then you'll have a new executable on your path: activestack-gateway
.
To start the gateway server with default options run:
> activestack-gateway server|s
To start the gateway console to control an already running server run:
> activestack-gateway console|c
Once you've started the active stack control console you can issue these commands to control the server:
quit
- to quit the consolerestart
- to restart the servershutdown
- to shut the server downloglevel
- set the log level # Not currently implementedclientmessageresendinterval
- print the client message resend interval configurationclientcount
- print the number of clients connected to the server
The AS Gateway allows several different configuration options. These can be specified using a customer configuration file.
# How often should server process send heartbeats to workers
cluster.heartbeatInterval=1000
# How long before a worker times out and is restarted
cluster.workerTimeout=5000
# DON'T KNOW
cluster.watchdogInterval=1000
# Get warned when memory reaches this level
cluster.memoryWarning.rss=1024
# Get warned when memory reaches this level
cluster.memoryWarning.heapTotal=60
# Hard memory limit
cluster.memoryLimit.rss=2048
# Hard memory limit
cluster.memoryLimit.heapUsed=100
# How long to wait before worker is restarted
cluster.workerRestartDelay=50
# Worker backoff
cluster.maxRestartBackoff=10
# The number of workers to spawn. If not specified will use (numCPUs/2)+1
cluster.workerCount=2
# Logging level
frontend.logLevel=info
# Shutdown password
frontend.shutdownCode=pass123
# The port to listen on
frontend.port=8080
# Use SSL or not
frontend.ssl=false
# Socket IO configurations
gateway.socketio.timeout=300
gateway.socketio.interval=20
# Redis configurations
gateway.redis.host=localhost
gateway.redis.port=6379
gateway.redis.password=
gateway.redis.gatewaycontrolqueue=gateway
gateway.redis.max_attempts=1
gateway.redis.offline_queue=false
# RabbitMQ configurations
gateway.rabbitmq.host=localhost
gateway.rabbitmq.port=5672
gateway.rabbitmq.login=guest
gateway.rabbitmq.password=guest
gateway.rabbitmq.durable=false
npm test
- gateway.js - Passed in the Express HTTP Server instance to listen for connect requests on.
- Sets up a redis listener for the SocketIO library to use. This is meant to allow each instance of a SocketIO listener to be stateless.
- Starts up a SocketIO listener, attaching itself to the ExpressJS HTTP Server instance passed in from server.js.
- As part of the SocketIO listener, a Flash Policy "Server" is also started for Flash based socket clients.
- Creates and starts a new RabbitMQ listener.
- Once the RabbitMQ listener is established (i.e. has emitted its
ready
event) the SocketIO has itsconnection
listener setup. - SocketIO
connection
listener handles a new client connect request by:- Storing a reference to the socket by its
socket.id
. - Adds listeners to the new socket for
disconnect
andlogout
. - Creates a new Client, passing in the new socket, RabbitMQ instance, and RabbitMQ exchange.
- Once the new Client is established it is meant to handle all communication with the client except in the case of a socket
disconnect
/logout
.
- Storing a reference to the socket by its
- Client
- Creates a new Session for the Client. A Session represents the state of the Client. In order to be stateless, the Session data is encrypted and sent to the client. The encrypted session data is considered to be the reconnect "key" for any client reconnect attempts. Whenever the Session data changes, the reconnect "key" is re-packaged and re-sent to the client.
- Sets up listeners for:
message
- Routes the message to all the clients registered agentslogout
- Routes the logout message to all the clients registered agentsdisconnect
- Routes the disconnect message to all the clients registered agentserror
- Handles the error accordingly, which potentially means invalidating and disposing of the Client.