This example demonstrate the usage of Channelz. For a better looking website, the gdebug uses gRPC-Web protocol and will serve all useful information in web pages.
Channelz is a channel tracing feature. It will track statistics like how many messages have been sent, how many of them failed, what are the connected sockets. Since it is implemented in C-Core and has low-overhead, it is recommended to turn on for production services. See Channelz design doc.
The tracing log generation might have larger overhead, especially when you try to trace transport. It would result in replicating the traffic loads. However, it is still the most powerful tool when you need to dive in.
Specify environment variables, then run your application:
GRPC_VERBOSITY=debug GRPC_TRACE=all
For more granularity, please see environment_variables.
GRPC_VERBOSITY=debug GRPC_TRACE=tcp,http,secure_endpoint,transport_security
GRPC_VERBOSITY=debug GRPC_TRACE=call_error,connectivity_state,pick_first,round_robin,glb
pdb is a debugging tool that is available for Python interpreters natively. You can set breakpoint, and execute commands while the application is stopped.
The simplest usage is add a single line in the place you want to inspect: import pdb; pdb.set_trace(). When interpreter see this line, it would pop out a interactive command line interface for you to inspect the application state.
For more detailed usage, see https://docs.python.org/3/library/pdb.html.
Caveat: gRPC Python uses C-Extension under-the-hood, so pdb may not be able to trace through the whole stack.
grpc_cli is a handy tool to interact with gRPC backend easily. Imageine you can inspect what service does a server provide without writing any code, and make gRPC calls just like curl.
The installation guide: https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md#code-location The usage guide: https://github.com/grpc/grpc/blob/master/doc/command_line_tool.md#usage The source code: https://github.com/grpc/grpc/blob/master/test/cpp/util/grpc_cli.cc