/**
* Create initial layout in filesystem.
* <ol>
* <li>Check if the root region exists and is readable, if not create it.
* Create hbase.version and the -ROOT- directory if not one.
* </li>
* <li>Create a log archive directory for RS to put archived logs</li>
* </ol>
* Idempotent.
*/
private Path createInitialFileSystemLayout() throws IOException {
// check if the root directory exists
checkRootDir(this.rootdir, conf, this.fs);
// check if temp directory exists and clean it
//确认缓存目录(/${hbase.rootdir}/.tmp)存在并且为空 此方法只是在当前节点成为active master后执行一次
checkTempDir(this.tempdir, conf, this.fs);
// '/${hbase.rootdir}/.oldlogs' 将要被删除的旧日志
Path oldLogDir = new Path(this.rootdir, HConstants.HREGION_OLDLOGDIR_NAME);
// Make sure the region servers can archive their old logs
if(!this.fs.exists(oldLogDir)) {
this.fs.mkdirs(oldLogDir);
}
return oldLogDir;
}
