anchor.diff:  
   By default, `$ mvn test -P runAllTests` runs all tests using a quarter of the CPUs available on machine
   hosting the test run (see `surefire.firstPartForkCount` and `surefire.secondPartForkCount` in the top-level
  -hbase `pom.xml`). Up these counts to get the build to run faster. You can also have hbase modules
  +hbase `pom.xml` which default to 0.25C, or 1/4 of CPU count). Up these counts to get the build to run faster.
  +You can also have hbase modules
   run their tests in parrallel when the dependency graph allows by passing `--threads=N` when you invoke
   maven, where `N` is the amount of parallelism wanted.
  +maven, where `N` is the amount of _module_ parallelism wanted.
   
   For example, allowing that you want to use all cores on a machine to run tests,
   you could start up the maven test run with:
  
positive.code: reliably with perhaps an unlucky sporadic flakey test failure. On other branches, the case may be less so with
  frequent flakies and even broken tests in need of attention that fail 100% of the time. Try and figure
  the state of tests on the branch you are currently interested in; the current state of nightly
  linke:https://builds.apache.org/view/H-L/view/HBase/job/HBase%20Nightly/[apache jenkins builds] is a good
  place to start. Tests on master branch are generally not in the best of condition as releases
  are less frequent off master. This can make it hard landing patches especially given our dictum that
  patches land on master branch first.
  
  The full test suite can take from 5-6 hours on an anemic VM with 4 CPUs and minimal
  parallelism to 50 minutes or less on a linux machine with dozens of CPUs.
  
  When you go to run the full test suite, make sure you up the test runner user nproc
  (`ulimit -u` -- make sure it > ~6000 or more even) and the number of files (`ulimit -n` -- make
  sure it > 10240 or so) limits on your system. Errors because the test run hits
  limits are often only opaquely related to the constraint. You can see the current
  user settings by running `ulimit -a`.
  
  
negative.code: 
  ----
  mvn test -PrunAllTests -Dtest.build.data.basedirectory=/ram2G
  ----
  
  [[hbase.unittests.cmds.test.hbasetests]]
  