/**
* Verify that the protocols are compatible, switch to a different protocol version, if we need
* to.
*/
private Protocol checkProtocol(Protocol protocol) throws IOException, ProtocolException {
ClientVersion clientVersion =
protocol.read(namedChannel.getChannel(), Protocol.ClientVersion.class);
clientId = clientVersion.getNodeId();
FeederManager.Lease lease = feederManager.leases.get(clientId);
if (lease != null) {
dbBackup = lease.terminate();
}
feederManager.feeders.put(clientId, this);
if (clientVersion.getVersion() != protocol.getVersion()) {
String message =
"Client requested protocol version: "
+ clientVersion.getVersion()
+ " but the server version is "
+ protocol.getVersion();
/*
* Simply log the difference on the server, it's up to the client
* to reject the protocol version, if it can't accommodate it.
*/
LoggerUtils.warning(logger, feederManager.getEnvImpl(), message);
}
protocol.write(protocol.new ServerVersion(), namedChannel);
/* In future we may switch protocol versions to accommodate the client.
* For now, simply return the one and only version.
*/
return protocol;
}
/** Sets up the channel to facilitate efficient transfer of large log files. */
private SocketChannel configureChannel() throws IOException {
namedChannel.getChannel().configureBlocking(true);
LoggerUtils.fine(
logger,
feederManager.getEnvImpl(),
"Log File Feeder accepted connection from " + namedChannel);
namedChannel.getChannel().socket().setSoTimeout(SOCKET_TIMEOUT_MS);
/*
* Enable Nagle's algorithm since throughput is important for the large
* files we will be transferring.
*/
namedChannel.getChannel().socket().setTcpNoDelay(false);
return namedChannel.getChannel();
}
/**
* Processes the request for the list of files that constitute a valid backup. If a leased
* DbBackup instance is available, it uses it, otherwise it creates a new instance and uses it
* instead.
*/
private void sendFileList(Protocol protocol)
throws IOException, ProtocolException, DatabaseException {
/* Wait for the request message. */
protocol.read(namedChannel.getChannel(), Protocol.FileListReq.class);
if (dbBackup == null) {
dbBackup = new DbBackup(feederManager.getEnvImpl());
dbBackup.startBackup();
} else {
feederManager.leaseRenewalCount++;
}
/*
* Remove the subdirectory header of the log files, because the nodes
* that need to copy those log files may not configure the spreading
* log files into sub directories feature.
*/
String[] files = dbBackup.getLogFilesInBackupSet();
for (int i = 0; i < files.length; i++) {
if (files[i].contains(File.separator)) {
files[i] = files[i].substring(files[i].indexOf(File.separator) + 1, files[i].length());
}
}
protocol.write(protocol.new FileListResp(files), namedChannel);
}
/** The main driver loop that enforces the protocol message sequence and implements it. */
@Override
public void run() {
/* The initial protocol */
Protocol protocol =
new Protocol(feederManager.nameIdPair, Protocol.VERSION, feederManager.getEnvImpl());
try {
configureChannel();
protocol = checkProtocol(protocol);
checkFeeder(protocol);
sendFileList(protocol);
sendRequestedFiles(protocol);
/* Done, cleanup */
dbBackup.endBackup();
dbBackup = null;
} catch (ClosedByInterruptException e) {
LoggerUtils.fine(
logger,
feederManager.getEnvImpl(),
"Ignoring ClosedByInterruptException normal shutdown");
} catch (IOException e) {
LoggerUtils.warning(logger, feederManager.getEnvImpl(), " IO Exception: " + e.getMessage());
} catch (ProtocolException e) {
LoggerUtils.severe(
logger, feederManager.getEnvImpl(), " Protocol Exception: " + e.getMessage());
} catch (Exception e) {
throw new EnvironmentFailureException(
feederManager.getEnvImpl(), EnvironmentFailureReason.UNCAUGHT_EXCEPTION, e);
} finally {
try {
namedChannel.getChannel().close();
} catch (IOException e) {
LoggerUtils.warning(
logger,
feederManager.getEnvImpl(),
"Log File feeder io exception on " + "channel close: " + e.getMessage());
}
shutdown();
if (dbBackup != null) {
if (feederManager.shutdown.get()) {
dbBackup.endBackup();
} else {
/*
* Establish lease so client can resume within the lease
* period.
*/
feederManager.new Lease(clientId, feederManager.leaseDuration, dbBackup);
LoggerUtils.info(
logger, feederManager.getEnvImpl(), "Lease created for node: " + clientId);
}
}
LoggerUtils.info(
logger,
feederManager.getEnvImpl(),
"Log file feeder for client: " + clientId + " exited");
}
}
/**
* Sends over the contents of the file and computes the SHA-1 hash. Note that the method does not
* rely on EOF detection, but rather on the promised file size, since the final log file might be
* growing while the transfer is in progress. The client uses the length sent in the FileResp
* message to maintain its position in the network stream. It expects to see a StatResp once it
* has read the agreed upon number of bytes.
*
* <p>Since JE log files are append only, there is no danger that we will send over any
* uninitialized file blocks.
*
* @param file the log file to be sent.
* @param the number of bytes to send
* @return the digest associated with the file that was sent
* @throws IOException
*/
private byte[] sendFileContents(File file, long length) throws IOException {
final LogVerifier verifier = new LogVerifier(feederManager.getEnvImpl(), file.getName(), -1L);
final FileInputStream fileStream = new FileInputStream(file);
try {
final FileChannel fileChannel = fileStream.getChannel();
messageDigest.reset();
final ByteBuffer buffer = ByteBuffer.allocateDirect(TRANSFER_BYTES);
final byte[] array = (buffer.hasArray()) ? buffer.array() : new byte[TRANSFER_BYTES];
int transmitBytes = 0;
while (true) {
buffer.clear();
if (fileChannel.read(buffer) < 0) {
verifier.verifyAtEof();
break;
}
buffer.flip();
final int lim = buffer.limit();
final int off;
if (buffer.hasArray()) {
off = buffer.arrayOffset();
} else {
off = 0;
buffer.get(array, 0, lim);
buffer.rewind();
}
verifier.verify(array, off, lim);
messageDigest.update(array, off, lim);
transmitBytes += namedChannel.getChannel().write(buffer);
}
if (transmitBytes != length) {
String msg =
"File length:"
+ length
+ " does not match the "
+ "number of bytes that were transmitted:"
+ transmitBytes;
throw new IllegalStateException(msg);
}
LoggerUtils.info(
logger,
feederManager.getEnvImpl(),
"Sent file: " + file + " Length: " + length + " bytes");
} finally {
fileStream.close();
}
return messageDigest.digest();
}
/**
* Implements the message exchange used to determine whether this feeder is suitable for use the
* client's backup needs. The feeder may be unsuitable if it's already busy, or it's not current
* enough to service the client's needs.
*/
private void checkFeeder(Protocol protocol) throws IOException, DatabaseException {
protocol.read(namedChannel.getChannel(), FeederInfoReq.class);
int feeders = feederManager.getActiveFeederCount() - 1 /* Exclude this one */;
VLSN rangeFirst = VLSN.NULL_VLSN;
VLSN rangeLast = VLSN.NULL_VLSN;
if (feederManager.getEnvImpl() instanceof RepImpl) {
/* Include replication stream feeders as a load component. */
RepImpl repImpl = (RepImpl) feederManager.getEnvImpl();
feeders += repImpl.getRepNode().feederManager().activeReplicaCount();
VLSNRange range = repImpl.getVLSNIndex().getRange();
rangeFirst = range.getFirst();
rangeLast = range.getLast();
}
protocol.write(protocol.new FeederInfoResp(feeders, rangeFirst, rangeLast), namedChannel);
}
/**
* Send files in response to request messages. The request sequence looks like the following:
*
* <p>[FileReq | StatReq]+ Done
*
* <p>The response sequence to a FileReq looks like:
*
* <p>FileStart <file byte stream> FileEnd
*
* <p>and that for a StatReq, is simply a StatResp
*/
private void sendRequestedFiles(Protocol protocol)
throws IOException, ProtocolException, DatabaseException {
try {
while (true) {
FileReq fileReq = protocol.read(namedChannel.getChannel(), FileReq.class);
final String fileName = fileReq.getFileName();
/*
* Calculate the full path for a specified log file name,
* especially when this Feeder is configured to run with sub
* directories.
*/
FileManager fMgr = feederManager.getEnvImpl().getFileManager();
File file = new File(fMgr.getFullFileName(fileName));
if (!file.exists()) {
throw EnvironmentFailureException.unexpectedState("Log file not found: " + fileName);
}
/* Freeze the length and last modified date. */
final long length = file.length();
final long lastModified = file.lastModified();
byte digest[] = null;
FileInfoResp resp = null;
Protocol.FileInfoResp cachedResp = feederManager.statResponses.get(fileName);
byte cachedDigest[] =
((cachedResp != null)
&& (cachedResp.getFileLength() == length)
&& (cachedResp.getLastModifiedTime() == lastModified))
? cachedResp.getDigestSHA1()
: null;
if (fileReq instanceof FileInfoReq) {
if (cachedDigest != null) {
digest = cachedDigest;
} else if (((FileInfoReq) fileReq).getNeedSHA1()) {
digest = getSHA1Digest(file, length).digest();
} else {
// Digest not requested
digest = new byte[0];
}
resp = protocol.new FileInfoResp(fileName, length, lastModified, digest);
} else {
protocol.write(protocol.new FileStart(fileName, length, lastModified), namedChannel);
digest = sendFileContents(file, length);
if ((cachedDigest != null) && !Arrays.equals(cachedDigest, digest)) {
throw EnvironmentFailureException.unexpectedState(
"Inconsistent cached and computed digests");
}
resp = protocol.new FileEnd(fileName, length, lastModified, digest);
}
/* Cache for subsequent requests, if it was computed. */
if (digest.length > 0) {
feederManager.statResponses.put(fileName, resp);
}
protocol.write(resp, namedChannel);
}
} catch (ProtocolException pe) {
if (pe.getUnexpectedMessage() instanceof Protocol.Done) {
return;
}
throw pe;
}
}
