* index_parallel: support !appendToExisting with no explicit intervals
This enables ParallelIndexSupervisorTask to dynamically request locks at runtime
if it is run without explicit intervals in the granularity spec and with
appendToExisting set to false. Previously, it behaved as if appendToExisting
was set to true, which was undocumented and inconsistent with IndexTask and
Hadoop indexing.
Also, when ParallelIndexSupervisorTask allocates segments in the explicit
interval case, fail if its locks on the interval have been revoked.
Also make a few other additions/clarifications to native ingestion docs.
Fixes#6989.
* Review feedback.
PR description on GitHub updated to match.
* Make native batch ingestion partitions start at 0
* Fix to previous commit
* Unit test. Verified to fail without the other commits on this branch.
* Another round of review
* Slightly scarier warning
David Glasser
Gian Merlino
Jihoon Son
David Lim
Vadim Ogievetsky
QiuMM
Jonathan Wei