/// <exception cref="System.IO.IOException"/>
private int DownloadImage(NNStorage storage, NamenodeProtocol proxy)
{
// Load the newly formatted image, using all of the directories
// (including shared edits)
long imageTxId = proxy.GetMostRecentCheckpointTxId();
long curTxId = proxy.GetTransactionID();
FSImage image = new FSImage(conf);
try
{
image.GetStorage().SetStorageInfo(storage);
image.InitEditLog(HdfsServerConstants.StartupOption.Regular);
System.Diagnostics.Debug.Assert(image.GetEditLog().IsOpenForRead(), "Expected edit log to be open for read"
);
// Ensure that we have enough edits already in the shared directory to
// start up from the last checkpoint on the active.
if (!skipSharedEditsCheck && !CheckLogsAvailableForRead(image, imageTxId, curTxId
))
{
return(ErrCodeLogsUnavailable);
}
image.GetStorage().WriteTransactionIdFileToStorage(curTxId);
// Download that checkpoint into our storage directories.
MD5Hash hash = TransferFsImage.DownloadImageToStorage(otherHttpAddr, imageTxId, storage
, true);
image.SaveDigestAndRenameCheckpointImage(NNStorage.NameNodeFile.Image, imageTxId,
hash);
}
catch (IOException ioe)
{
image.Close();
throw;
}
return(0);
}