rpcpdb 0.4

Debug support for RPC servers

A PDB wrapper designed to be part of RPC systems for remote introspection and debugging of RPC server state

Features

• debug any API function from the client side

• store a trace file from any API function

• open an interactive console into the RPC process

• match and ignore count on function breakpoints

• Python 2 and 3 support

About

rpcpdb supports three main functions to support debugging of RPC contexts:

• a wrapper around the pdb debugger with stdio routed over a UNIX socket

• tracing of API functions

• an interactive console available within the target RPC process

It is designed to fulfil the need to debug a function on an already-running server which uses threads or processes to dispatch each remote procedure call, without having to change the source code to the server in any way. There is no disruption to other clients and rpc calls while the selected call is being debugged or traced.

In particular, a mixin class is provided which adds a small number of debug and trace methods to your RPC server. These allow breakpoints to be controlled by another RPC client.

For an example, run the xmlrpc_server.py server process, then run one or more xmlrpc_client.py processes which will continually perform RPC requests against it. xmlrpc_debug.py can then be run to inject a debug breakpoint in a method which the clients are continually calling; the next client to call that function will be remotely debuggable, while other clients carry on oblivious.

An alternative example added in v0.2 is the ‘test_server.py’ which does not use RPC but runs functions in background threads. It gives a good overview of usage in a single module without extra dependencies.

Currently the debug interface is provided via a UNIX socket, but this will be extended in future.

RPC framework support is intended to cover XMLRPC, RPyC and Pyro in the initial stages.

Plans

• Update examples, tidy up, document.

• Support other interfaces than termsock / UNIX socket.

• Support json-rpc

• Improve API tracing functionality

License information

Copyright (c) 2010-2013 Ben Bass <[e-mail]> All rights reserved.

See the file “LICENSE” for information terms & conditions for usage, and a DISCLAIMER OF ALL WARRANTIES.