/// <summary>Get a RemoteBlockReader that communicates over a TCP socket.</summary>
/// <returns>
/// The new BlockReader. We will not return null, but instead throw
/// an exception if this fails.
/// </returns>
/// <exception cref="Org.Apache.Hadoop.Security.Token.SecretManager.InvalidToken">
/// If the block token was invalid.
/// InvalidEncryptionKeyException
/// If the encryption key was invalid.
/// Other IOException
/// If there was another problem.
/// </exception>
/// <exception cref="System.IO.IOException"/>
private BlockReader GetRemoteBlockReaderFromTcp()
{
if (Log.IsTraceEnabled())
{
Log.Trace(this + ": trying to create a remote block reader from a " + "TCP socket"
);
}
BlockReader blockReader = null;
while (true)
{
BlockReaderFactory.BlockReaderPeer curPeer = null;
Peer peer = null;
try
{
curPeer = NextTcpPeer();
if (curPeer.fromCache)
{
remainingCacheTries--;
}
peer = curPeer.peer;
blockReader = GetRemoteBlockReader(peer);
return(blockReader);
}
catch (IOException ioe)
{
if (IsSecurityException(ioe))
{
if (Log.IsTraceEnabled())
{
Log.Trace(this + ": got security exception while constructing " + "a remote block reader from "
+ peer, ioe);
}
throw;
}
if ((curPeer != null) && curPeer.fromCache)
{
// Handle an I/O error we got when using a cached peer. These are
// considered less serious, because the underlying socket may be
// stale.
if (Log.IsDebugEnabled())
{
Log.Debug("Closed potentially stale remote peer " + peer, ioe);
}
}
else
{
// Handle an I/O error we got when using a newly created peer.
Log.Warn("I/O error constructing remote block reader.", ioe);
throw;
}
}
finally
{
if (blockReader == null)
{
IOUtils.Cleanup(Log, peer);
}
}
}
}
/// <summary>Get a RemoteBlockReader that communicates over a UNIX domain socket.</summary>
/// <returns>
/// The new BlockReader, or null if we failed to create the block
/// reader.
/// </returns>
/// <exception cref="Org.Apache.Hadoop.Security.Token.SecretManager.InvalidToken">
/// If the block token was invalid.
/// Potentially other security-related execptions.
/// </exception>
/// <exception cref="System.IO.IOException"/>
private BlockReader GetRemoteBlockReaderFromDomain()
{
if (pathInfo == null)
{
pathInfo = clientContext.GetDomainSocketFactory().GetPathInfo(inetSocketAddress,
conf);
}
if (!pathInfo.GetPathState().GetUsableForDataTransfer())
{
PerformanceAdvisory.Log.Debug(this + ": not trying to create a " + "remote block reader because the UNIX domain socket at "
+ pathInfo + " is not usable.");
return(null);
}
if (Log.IsTraceEnabled())
{
Log.Trace(this + ": trying to create a remote block reader from the " + "UNIX domain socket at "
+ pathInfo.GetPath());
}
while (true)
{
BlockReaderFactory.BlockReaderPeer curPeer = NextDomainPeer();
if (curPeer == null)
{
break;
}
if (curPeer.fromCache)
{
remainingCacheTries--;
}
DomainPeer peer = (DomainPeer)curPeer.peer;
BlockReader blockReader = null;
try
{
blockReader = GetRemoteBlockReader(peer);
return(blockReader);
}
catch (IOException ioe)
{
IOUtils.Cleanup(Log, peer);
if (IsSecurityException(ioe))
{
if (Log.IsTraceEnabled())
{
Log.Trace(this + ": got security exception while constructing " + "a remote block reader from the unix domain socket at "
+ pathInfo.GetPath(), ioe);
}
throw;
}
if (curPeer.fromCache)
{
// Handle an I/O error we got when using a cached peer. These are
// considered less serious, because the underlying socket may be stale.
if (Log.IsDebugEnabled())
{
Log.Debug("Closed potentially stale domain peer " + peer, ioe);
}
}
else
{
// Handle an I/O error we got when using a newly created domain peer.
// We temporarily disable the domain socket path for a few minutes in
// this case, to prevent wasting more time on it.
Log.Warn("I/O error constructing remote block reader. Disabling " + "domain socket "
+ peer.GetDomainSocket(), ioe);
clientContext.GetDomainSocketFactory().DisableDomainSocketPath(pathInfo.GetPath()
);
return(null);
}
}
finally
{
if (blockReader == null)
{
IOUtils.Cleanup(Log, peer);
}
}
}
return(null);
}
