Initial READMEs for domains.

README.md

@@ -1,20 +1,24 @@
 # Diagnostics Working Group  
 The goal of this WG is to ensure Node provides a set of comprehensive, documented, extensible diagnostic protocols, formats, and APIs to enable tool vendors to provide reliable diagnostic tools for Node.
 
-To facilitate this, work is divided into several domains:
-- Tracing and Logging
-- Profiling
-- Heap and Memory Analysis
-- Step Debugging
-- Protocol and API
+Work is divided into several domains:
+- [Tracing](./tracing)
+- [Profiling](./profiling)
+- [Heap and Memory Analysis](./heap-memory)
+- [Step Debugging](./debugging)
 
 Background, reference documentation, samples, and discussion for each domain is contained within its folder.
 
-# Logistics
+Work needed includes:  
+- Collect, understand, and document existing diagnostic capabilities and entry-points throughout Node, V8, and other components.
+- Collect and document projects and products providing diagnostics for Node with brief description of their technical architecture and sponsoring organizations.
+- Identify opportunities and gaps, then propose and implement solutions.
+
+### Logistics
 - Monthly Meetings
 - Biannual F2F
 
-# Members  
+### Members  
 * @bnoordhuis 
 * @sam-github 
 * @othiym23 

debugging/README.md

@@ -0,0 +1,29 @@
+## Debugging API
+- [Chrome Debugging Protocol](https://chromedevtools.github.io/debugger-protocol-viewer/)
+- [V8 Debugging Protocol](https://github.com/v8/v8/wiki/Debugging-Protocol)
+
+Node currently relies on V8's internal Debug API and associated commands and events. The Debug API is published at [v8/include/v8-debug.h](https://github.com/v8/v8/blob/master/include/v8-debug.h), and the message protocol is documented in prose in [the V8 wiki](https://github.com/v8/v8/wiki/Debugging-Protocol) and in code in [v8/src/debug/debug.js#L2341-2372](https://github.com/v8/v8/blob/master/src/debug/debug.js#L2341-L2372). 
+
+Node also provides an agent [node/src/debug-agent.h](https://github.com/blob/master/src/debug-agent.h) which relays requests, responses, and events through a TCP socket, and a command-line debugger [node/lib/_debugger.js](https://github.com/blob/master/lib/_debugger.js).
+
+The Chrome/V8 team has deprecated the internal V8 API and command set and proposed replacing it with a subset of the Chrome Debugging Protocol (CrDP), see https://github.com/nodejs/node/issues/2546. CrDP is documented at [https://chromedevtools.github.io/debugger-protocol-viewer/]() and the backing GitHub repo.
+
+The [cyrus-and/chrome-remote-interface](https://github.com/cyrus-and/chrome-remote-interface) library provides a JS proxy for CrDP.
+
+## Step Debugging Tools  
+Name | Sponsor
+-----|--------
+[node-inspector][] | StrongLoop
+[JetBrains WebStorm][] | JetBrains
+[Visual Studio Code][] | Microsoft
+[Node CLI Debugger][] | Node Foundation
+[Chrome DevTools][] | Google
+[Theseus][] | Adobe Research
+
+[node-inspector]: https://github.com/node-inspector/node-inspector 
+[JetBrains WebStorm]: https://www.jetbrains.com/help/webstorm/2016.1/running-and-debugging-node-js.html
+[Visual Studio Code]: https://github.com/Microsoft/vscode
+[Node CLI Debugger]: https://nodejs.org/api/debugger.html
+[Chrome DevTools]: https://github.com/ChromeDevTools/devtools-frontend
+[Theseus]: https://github.com/adobe-research/theseus
+

heap-memory/README.md

@@ -0,0 +1,10 @@
+## Heap and Memory Analysis  
+The [nodejs/post-mortem](https://github.com/nodejs/post-mortem) WG is responsible for this domain.
+
+### Heap Analysis  
+- [mdb_v8](https://github.com/joyent/mdb_v8)
+- [node-heapdump](https://github.com/bnoordhuis/node-heapdump)
+- [llnode](https://github.com/indutny/llnode)
+- [IBM IDDE](https://www.ibm.com/developerworks/java/jdk/tools/idde/)
+- [Snapshot Utils](https://github.com/bmeck/snapshot-utils)
+

profiling/README.md

@@ -0,0 +1,26 @@
+## Profiling for Node  
+- CPU Profiling
+  - V8 CPU Profiler: [v8/include/v8-profiler.h](https://github.com/v8/blob/master/include/v8-profiler.h)
+    - Accessible globally through `--prof` runtime flag, basic processing and display through `--prof-processor` runtime flag
+  - Intel vTune profiler. Accessible through `--enable-vtune-profiling` compile-time flag.
+
+- Heap Profiling
+  - V8 Heap Profiler: [v8/include/v8-profiler.h](https://github.com/v8/blob/master/include/v8-profiler.h)
+    - Also accessible through built-in 'v8' module.
+
+Name | Sponsor
+-----|--------
+[v8-profiler][] | StrongLoop
+[Chrome DevTools][] | Google
+
+[v8-profiler]: https://github.com/node-inspector/v8-profiler
+[Chrome DevTools]: https://github.com/ChromeDevTools/devtools-frontend
+
+### Stack Analysis  
+- [0x](https://github.com/davidmarkclements/0x)
+- [StackVis](https://github.com/joyent/node-stackvis)
+
+## Docs  
+[guides/simple-profiling](https://nodejs.org/en/docs/guides/simple-profiling/)
+[paulirish/automated-chrome-profiling](https://github.com/paulirish/automated-chrome-profiling)
+

tracing/README.md

@@ -1,5 +1,9 @@
-## Tracing and Logging  
+## Tracing  
 - [AsyncWrap](./AsyncWrap/README.md) - Most native objects are represented indirectly by the [AsyncWrap class](https://github.com/nodejs/node/blob/master/src/async-wrap.h), so hooks have been added to that class to trace lifecycle (init/destroy) and callback activity (pre/post) related to these objects.
+
 - [OS Tracing](./os-tracing/README.md) - LTTng (Linux), DTrace (Linux, OSX), ETW (Windows)
+
 - [VM Tracing](./vm-tracing/README.md) - Tracing native to JS VMs, such as V8's TRACE_EVENT.
 
+- [Domains and Zones][] - 
+

tracing/os-tracing/README.md

@@ -1,20 +1,24 @@
 ## OS Tracing  
 
 * [DTrace](http://dtrace.org/)  
-  Available on IllumOS, Solaris, Mac, Linux
-
+  Available on IllumOS, Solaris, Mac
   The [DTrace blog](http://dtrace.org/blogs/blog/category/node-js/) has some articles on using DTrace with Node.js
 
 * [LTTng](http://lttng.org/)  
-  Linux only.
-
+  Linux only.  
   Some info on using LTTng with Node.js are available in the presentations
   [Tracing Node on Linux with LTTNG](http://nearform.github.io/tracing-node-lttng-nodejsdublin/)
 
 * [ETW](https://msdn.microsoft.com/en-us/library/windows/desktop/aa363668.aspx)  
-  Windows only.
-
+  Windows only.  
   Some information was provided by Bill Ticehurst (@billti) in
   [issue #10](https://github.com/nodejs/tracing-wg/issues/10#issuecomment-137145822)
   about how he integrated ETW into Node.js for Windows
 
+* [Perf](https://perf.wiki.kernel.org/)  
+  Linux only.  
+  Can be enabled with `--perf_basic_prof` v8 run-time flag.
+
+* [SystemTap](https://sourceware.org/systemtap/)  
+  Linux only.
+