/// <exception cref="System.IO.IOException"/>
internal static void DoMerge(CheckpointSignature sig, RemoteEditLogManifest manifest
, bool loadImage, FSImage dstImage, FSNamesystem dstNamesystem)
{
NNStorage dstStorage = dstImage.GetStorage();
dstStorage.SetStorageInfo(sig);
if (loadImage)
{
FilePath file = dstStorage.FindImageFile(NNStorage.NameNodeFile.Image, sig.mostRecentCheckpointTxId
);
if (file == null)
{
throw new IOException("Couldn't find image file at txid " + sig.mostRecentCheckpointTxId
+ " even though it should have " + "just been downloaded");
}
dstNamesystem.WriteLock();
try
{
dstImage.ReloadFromImageFile(file, dstNamesystem);
}
finally
{
dstNamesystem.WriteUnlock();
}
dstNamesystem.ImageLoadComplete();
}
// error simulation code for junit test
CheckpointFaultInjector.GetInstance().DuringMerge();
Checkpointer.RollForwardByApplyingLogs(manifest, dstImage, dstNamesystem);
// The following has the side effect of purging old fsimages/edit logs.
dstImage.SaveFSImageInAllDirs(dstNamesystem, dstImage.GetLastAppliedTxId());
dstStorage.WriteAll();
}
public override void Stop()
{
// NameNode
if (checkpointManager != null)
{
// Prevent from starting a new checkpoint.
// Checkpoints that has already been started may proceed until
// the error reporting to the name-node is complete.
// Checkpoint manager should not be interrupted yet because it will
// close storage file channels and the checkpoint may fail with
// ClosedByInterruptException.
checkpointManager.shouldRun = false;
}
if (namenode != null && GetRegistration() != null)
{
// Exclude this node from the list of backup streams on the name-node
try
{
namenode.ErrorReport(GetRegistration(), NamenodeProtocol.Fatal, "Shutting down.");
}
catch (IOException e)
{
Log.Error("Failed to report to name-node.", e);
}
}
// Stop the RPC client
if (namenode != null)
{
RPC.StopProxy(namenode);
}
namenode = null;
// Stop the checkpoint manager
if (checkpointManager != null)
{
checkpointManager.Interrupt();
checkpointManager = null;
}
// Abort current log segment - otherwise the NN shutdown code
// will close it gracefully, which is incorrect.
GetFSImage().GetEditLog().AbortCurrentLogSegment();
// Stop name-node threads
base.Stop();
}
/// <summary>Start a backup node daemon.</summary>
/// <exception cref="System.IO.IOException"/>
private void RunCheckpointDaemon(Configuration conf)
{
checkpointManager = new Checkpointer(conf, this);
checkpointManager.Start();
}
