/// <summary>Load one storage directory.</summary>
/// <remarks>Load one storage directory. Recover from previous transitions if required.
/// </remarks>
/// <param name="datanode">datanode instance</param>
/// <param name="nsInfo">namespace information</param>
/// <param name="dataDir">the root path of the storage directory</param>
/// <param name="startOpt">startup option</param>
/// <returns>the StorageDirectory successfully loaded.</returns>
/// <exception cref="System.IO.IOException"/>
private Storage.StorageDirectory LoadStorageDirectory(DataNode datanode, NamespaceInfo
nsInfo, FilePath dataDir, HdfsServerConstants.StartupOption startOpt)
{
Storage.StorageDirectory sd = new Storage.StorageDirectory(dataDir, null, true);
try
{
Storage.StorageState curState = sd.AnalyzeStorage(startOpt, this);
switch (curState)
{
case Storage.StorageState.Normal:
{
// sd is locked but not opened
break;
}
case Storage.StorageState.NonExistent:
{
Log.Info("Block pool storage directory " + dataDir + " does not exist");
throw new IOException("Storage directory " + dataDir + " does not exist");
}
case Storage.StorageState.NotFormatted:
{
// format
Log.Info("Block pool storage directory " + dataDir + " is not formatted for " + nsInfo
.GetBlockPoolID());
Log.Info("Formatting ...");
Format(sd, nsInfo);
break;
}
default:
{
// recovery part is common
sd.DoRecover(curState);
break;
}
}
// 2. Do transitions
// Each storage directory is treated individually.
// During startup some of them can upgrade or roll back
// while others could be up-to-date for the regular startup.
DoTransition(datanode, sd, nsInfo, startOpt);
if (GetCTime() != nsInfo.GetCTime())
{
throw new IOException("Data-node and name-node CTimes must be the same.");
}
// 3. Update successfully loaded storage.
SetServiceLayoutVersion(GetServiceLayoutVersion());
WriteProperties(sd);
return(sd);
}
catch (IOException ioe)
{
sd.Unlock();
throw;
}
}
/// <summary>
/// Analyze backup storage directories for consistency.<br />
/// Recover from incomplete checkpoints if required.<br />
/// Read VERSION and fstime files if exist.<br />
/// Do not load image or edits.
/// </summary>
/// <exception cref="System.IO.IOException">if the node should shutdown.</exception>
internal virtual void RecoverCreateRead()
{
for (IEnumerator <Storage.StorageDirectory> it = storage.DirIterator(); it.HasNext
();)
{
Storage.StorageDirectory sd = it.Next();
Storage.StorageState curState;
try
{
curState = sd.AnalyzeStorage(HdfsServerConstants.StartupOption.Regular, storage);
switch (curState)
{
case Storage.StorageState.NonExistent:
{
// sd is locked but not opened
// fail if any of the configured storage dirs are inaccessible
throw new InconsistentFSStateException(sd.GetRoot(), "checkpoint directory does not exist or is not accessible."
);
}
case Storage.StorageState.NotFormatted:
{
// for backup node all directories may be unformatted initially
Log.Info("Storage directory " + sd.GetRoot() + " is not formatted.");
Log.Info("Formatting ...");
sd.ClearDirectory();
// create empty current
break;
}
case Storage.StorageState.Normal:
{
break;
}
default:
{
// recovery is possible
sd.DoRecover(curState);
break;
}
}
if (curState != Storage.StorageState.NotFormatted)
{
// read and verify consistency with other directories
storage.ReadProperties(sd);
}
}
catch (IOException ioe)
{
sd.Unlock();
throw;
}
}
}
/// <summary>Analyze checkpoint directories.</summary>
/// <remarks>
/// Analyze checkpoint directories.
/// Create directories if they do not exist.
/// Recover from an unsuccessful checkpoint if necessary.
/// </remarks>
/// <exception cref="System.IO.IOException"/>
internal virtual void RecoverCreate(bool format)
{
storage.AttemptRestoreRemovedStorage();
storage.UnlockAll();
for (IEnumerator <Storage.StorageDirectory> it = storage.DirIterator(); it.HasNext
();)
{
Storage.StorageDirectory sd = it.Next();
bool isAccessible = true;
try
{
// create directories if don't exist yet
if (!sd.GetRoot().Mkdirs())
{
}
}
catch (SecurityException)
{
// do nothing, directory is already created
isAccessible = false;
}
if (!isAccessible)
{
throw new InconsistentFSStateException(sd.GetRoot(), "cannot access checkpoint directory."
);
}
if (format)
{
// Don't confirm, since this is just the secondary namenode.
Log.Info("Formatting storage directory " + sd);
sd.ClearDirectory();
}
Storage.StorageState curState;
try
{
curState = sd.AnalyzeStorage(HdfsServerConstants.StartupOption.Regular, storage);
switch (curState)
{
case Storage.StorageState.NonExistent:
{
// sd is locked but not opened
// fail if any of the configured checkpoint dirs are inaccessible
throw new InconsistentFSStateException(sd.GetRoot(), "checkpoint directory does not exist or is not accessible."
);
}
case Storage.StorageState.NotFormatted:
{
break;
}
case Storage.StorageState.Normal:
{
// it's ok since initially there is no current and VERSION
// Read the VERSION file. This verifies that:
// (a) the VERSION file for each of the directories is the same,
// and (b) when we connect to a NN, we can verify that the remote
// node matches the same namespace that we ran on previously.
storage.ReadProperties(sd);
break;
}
default:
{
// recovery is possible
sd.DoRecover(curState);
break;
}
}
}
catch (IOException ioe)
{
sd.Unlock();
throw;
}
}
}