Drill-4581: Extensive revisions to the Drill launch scripts.
See DRILL-4581 and DRILL-4591 for an overview.
See DRILL-4581 for a detailed list of bugs fixed.
See DRILL-4591 for the motivation for the new "site" directory support.
Changes support DRILL-1170 (Drill-on-YARN).
Broad overview of changes:
* Extended the existing "config" directory concept to create a
"site" directory that holds all site-specific files, leaving the
Drill directory ($DRILL_HOME) to contain only Drill-provided files.
The site directory is handy for all Drill users because it eases
upgrades, but is necessary to simplify Drill-on-YARN deployments.
Use the --config (for backward compatibility) or --site (more
descriptive) option to point to the site directory.
* Moved distribution-specific settings, and Drill defaults, out of
drill-env.sh. Now, drill-env.sh contains only user settings, avoiding
the need to do multi-way merges on upgrades. Distribution-specific
files now reside in a new $DRILL_HOME/conf/distrib-env.sh file.
* Refactored the launch scripts to allow the bulk of setup to be shared
between the "classic" Drill daemon script (drillbit.sh) and the new
Drill-on-YARN scripts.
* Added a new "run" option to drillbit.sh to allow Drill to run as a
child process as needed by tools such as Apache Mesos.
* Changes ensure backward compatibility. Users of earlier releases can
upgrade to the release with this fix without doing anything special.
Drill will "just work." However, users can optionally clean up the
drill-env.sh script, optionally use the site directory, and so on.
However these upgrades are not required.
closes #547
Committer
Sudheesh Katkam
