[HDFS-495] Hadoop FSNamesystem startFileInternal() getLease() has bug

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 0.20.1
• Fix Version/s: 0.20.2
• Component/s: namenode
• Assignee: Unassigned
• Reporter: Ruyue Ma
• Due: 24/Jul/09
• Created: 20/Jul/09 06:35
• Updated: 06/Aug/10 21:36
• Resolved: 19/Jan/10 22:48

Description

Original Code:

//
// If the file is under construction , then it must be in our
// leases. Find the appropriate lease record.
//
Lease lease = leaseManager.getLease(new StringBytesWritable(holder));
//
// We found the lease for this file. And surprisingly the original
// holder is trying to recreate this file. This should never occur.
//
if (lease != null)

{ throw new AlreadyBeingCreatedException( "failed to create file " + src + " for " + holder + " on client " + clientMachine + " because current leaseholder is trying to recreate file."); }

Problem: if another client (who has had some file leases) to recreate the underconstruction file, it can't trigger the lease recovery.
Reason: we should do:

if (new StringBytesWritable(holder).equals(pendingFile.clientName)){
throw new AlreadyBeingCreatedException(
"failed to create file " + src + " for " + holder +
" on client " + clientMachine +
" because current leaseholder is trying to recreate file.");
}

Issue Links

• is blocked by: HDFS-200 In HDFS, sync() not yet guarantees data available to the new readers