Crossbar.io is currently an interesting approach IMO.
It does have a single point of failure that is also a bottleneck (the router) and it's a lot of work to load balance / failover it.
But other than that, it provides a fantastic way to make microservices:
- anything is a client of the crossbar router. Your server code is a client. The db can be a client. The web page JS code is a client. And they all talk to each others.
- A client can expose any function to be called remotely by giving it a name. Another client can call this function by simply providing the name. Clients don't need to know each others. Routed RPC completly decoupled the clients from each others.
- A client can subscribe to a topic at any time and be notified when anothe client publishes a message on that topic. Quick, easy and powerful PUB/SUB with wildcard.
- A client can be written in JS (node and browser), Python, C#, Java, PHP, etc. Clients from other languages can talk to each others transparently. They all just receive JSON/msgpack/whatever and error are propagated and turn into the native language error handling mechanisme transparently.
- The API is pretty simple. If you tried SOAP or CORBA before, this is way, way, way simpler. It feels more like using redis.
- It uses websockets, which mean it works anywhere HTTP works. Including a web page or behind a NAT or with TLS.
- Everything is async. The router handles 6000 msg / s to 1000 clients on a small Raspberry Pi.
- The router can act as a process manager and even a static / wsgi web server.
- you can load balance any clients, hot swap them, ban them, get meta event about the whole system, etc.
- you can asign clients permissions, authentications, etc. Sessions are attached to each connexion, so clients knows what other clients can do.
It does have a single point of failure that is also a bottleneck (the router) and it's a lot of work to load balance / failover it.
But other than that, it provides a fantastic way to make microservices:
- anything is a client of the crossbar router. Your server code is a client. The db can be a client. The web page JS code is a client. And they all talk to each others.
- A client can expose any function to be called remotely by giving it a name. Another client can call this function by simply providing the name. Clients don't need to know each others. Routed RPC completly decoupled the clients from each others.
- A client can subscribe to a topic at any time and be notified when anothe client publishes a message on that topic. Quick, easy and powerful PUB/SUB with wildcard.
- A client can be written in JS (node and browser), Python, C#, Java, PHP, etc. Clients from other languages can talk to each others transparently. They all just receive JSON/msgpack/whatever and error are propagated and turn into the native language error handling mechanisme transparently.
- The API is pretty simple. If you tried SOAP or CORBA before, this is way, way, way simpler. It feels more like using redis.
- It uses websockets, which mean it works anywhere HTTP works. Including a web page or behind a NAT or with TLS.
- Everything is async. The router handles 6000 msg / s to 1000 clients on a small Raspberry Pi.
- The router can act as a process manager and even a static / wsgi web server.
- you can load balance any clients, hot swap them, ban them, get meta event about the whole system, etc.
- you can asign clients permissions, authentications, etc. Sessions are attached to each connexion, so clients knows what other clients can do.