Currently, things just fail. Ideally, the SolrCore would wait until safe mode was exited and resume loading.
This significantly improves how the various hdfs components handle running into safe mode on startup. Also includes random testing that hits HdfsLockFactory, HdfsDirectory, and HdfsUpdateLog.
Commit 1560553 from Mark Miller in branch 'dev/trunk'
[ https://svn.apache.org/r1560553 ]
SOLR-5657: When a SolrCore starts on HDFS, it should gracefully handle HDFS being in safe mode.
Commit 1560554 from Mark Miller in branch 'dev/branches/branch_4x'
[ https://svn.apache.org/r1560554 ]