aiogrpc

asyncio wrapper for grpc.io. Currently, only client-side interfaces are supported.

Interfaces

aiogrpc has exactly the same interface as grpc.io (https://grpc.io/grpc/python/grpc.html#module-grpc), except:

• All callbacks are called with call_soon_threadsafe() to run in the same thread with the event loop
• All futures are asyncio futures (i.e. awaitable)
• All blocking interfaces (__call__ for unary methods, code(), details(), ...) become coroutines
• Stream input/output are async iterators
• close() method returns a asyncio future (use await channel.close()) (since v1.4)

Usage

1. Compile your proto file with protoc to generate stub files

2. Use the stub files with aiogrpc.Channel, instead of grpc.Channel:

   from aiogrpc import insecure_channel
   import asyncio
   from mystub import MyStub
   
   channel = insecure_channel('ipv4:///127.0.0.1:8080')
   mystub = MyStub(channel)
   
   async def test_call():
       return await mystub.mymethod(...)
   
   async def test_call_stream():
       async for v in mystub.my_stream_method(...):
           ...

Balancing

Same as the original grpc.io, balancing (fail over) between multiple servers are supported:

1. Use multiple IPv4 or IPv6 addresses for balancing - use target like: "ipv4:///1.2.3.4:9999,1.2.3.5:9999,1.2.3.6:9999" or "ipv6:///[1::2]:9999,[1::3]:9999,[1::4]:9999"

2. Specify ONE DNS name which resolves to multiple addresses. GRPC will balance between the resolved addresses, and try to update the resolving result in interval. Example: "dns:///myserver:9999"

Notice that you cannot mix up IPv4, IPv6 and DNS addresses; only addresses with the same type can be balanced. Also, when using DNS target, only one DNS name can be specified.

The default load balancing strategy is "pick_first" (fail-over). Set "grpc.lb_policy_name" option to "round_robin" for round-robin load balancing: channel = insecure_channel('ipv4:///1.2.3.4:9999,1.2.3.5:9999,1.2.3.6:9999', [('grpc.lb_policy_name', 'round_robin')])

Copyright Notice

All code are published under Apache 2.0 License

Some code and docstrings are modified from grpc.io (https://grpc.io/grpc/python/grpc.html#module-grpc)