As a relatively unknown debugging tool for simulation tests, one could
have simulation print when a particular key is handled in various stages
of the commit process. This functionality was enabled by changing a 0
to a 1 in an #if, and changing a constant to the key in question.
As a proxy and storage server handle mutations, they call debugMutation
or debugKeyRange, which then checks against the mutation against the key
in question, and logs if they match. A mixture of printfs and
TraceEvents would then be emitted, and for this to actually be usable,
one also needs to comment out some particularly spammy debugKeyRange()
calls.
This PR reworks the API of debugMutation/debugKeyRange, pulls it out
into its own file, and trims what is logged by default into something
useful and understandable:
* debugMutation() now returns a TraceEvent, that one can add more details to before it is logged.
* Data distribution and storage server cleanup operations are no longer logged by default
Alex Miller