[WIP] Automated Failure Testing

[lithp]

For #2001

Done:

• Create a daemon which backgrounds gdb and allows us to send commands to it.

Some things we might want to add:

• Have make check fail if the tests reference function names which no longer exist.

[codecov]

Codecov Report

Merging #2044 into master will increase coverage by 0.54%.
The diff coverage is n/a.

@@            Coverage Diff             @@
##           master    #2044      +/-   ##
==========================================
+ Coverage   93.49%   94.04%   +0.54%     
==========================================
  Files         100      100              
  Lines       26104    29201    +3097     
==========================================
+ Hits        24407    27461    +3054     
- Misses       1697     1740      +43

[mtuncer]

can you make this a relative path ?

[lithp]

I think eventually it'll need to be a hostname:port tuple, otherwise this won't work on Windows.

[marcocitus]

The API seems a bit messy at the moment. Would it make sense to do something like:

SELECT citus.gdb_init();
SELECT citus.gdb_break('NeedsDistributedPlanning');
SELECT citus.gdb_continue();

[lithp]

Yeah, 100%. This API isn't very user friendly. I haven't made it nicer yet for a couple reasons:

• I'm not sure what the right API is yet, I want to write some more tests before deciding what the right set of concepts is.
• These functions are a little hard to add and iterate on. I haven't figured out how to share code between the functions so I need to copy and paste the code for connecting to a socket and modify it in all of them whenever it changes. For now just having a run_command is easier to develop with.