[HBASE-7970] Improve file descriptor usage: currently, there are two file descriptors per storefile

• Type: Sub-task
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Assignee: Sergey Shelukhin
• Reporter: Himanshu Vashishtha
• Created: 01/Mar/13 19:10
• Updated: 16/Jun/22 05:30
• Resolved: 29/Apr/13 21:40

Description

This is because there are two open calls in the HFile: one with checksum and another for without checksum support in v2:
see the method in HFile:createReaderWithEncoding()

FSDataInputStream fsdis = fs.open(path);
FSDataInputStream fsdisNoFsChecksum = fsdis;
// If the fs is not an instance of HFileSystem, then create an
// instance of HFileSystem that wraps over the specified fs.
// In this case, we will not be able to avoid checksumming inside
// the filesystem.
if (!(fs instanceof HFileSystem)) {
  hfs = new HFileSystem(fs);
} else {
  hfs = (HFileSystem)fs;
  // open a stream to read data without checksum verification in
  // the filesystem
  fsdisNoFsChecksum = hfs.getNoChecksumFs().open(path);
}