private void driveClientIO() throws IOException, GearmanException {
for (GearmanJobServerSession sess : sessionsMap.values()) {
int interestOps = SelectionKey.OP_READ;
if (sess.sessionHasDataToWrite()) {
interestOps |= SelectionKey.OP_WRITE;
}
try {
sess.getSelectionKey().interestOps(interestOps);
} catch (IllegalStateException ise) {
LOG.warn("Unable to drive IO for session " + sess + "," + " skipping.", ise);
continue;
}
}
ioAvailable.selectNow();
Set<SelectionKey> keys = ioAvailable.selectedKeys();
LOG.trace(
"Driving IO for client "
+ this
+ ". "
+ keys.size()
+ " session(s) currently available for IO");
Iterator<SelectionKey> iter = keys.iterator();
while (iter.hasNext()) {
SelectionKey key = iter.next();
GearmanJobServerSession s = sessionsMap.get(key);
s.driveSessionIO();
}
}
public boolean addServer(GearmanJobServerConnection conn)
throws IllegalArgumentException, IllegalStateException {
if (conn == null) {
throw new IllegalArgumentException("Connection can not be null");
}
// this is a sub-optimal way to look for dups, but addJobServer
// ops should be infrequent enough that this should be a big penalty
for (GearmanJobServerSession sess : sessionMap.values()) {
if (sess.getConnection().equals(conn)) {
return true;
}
}
GearmanJobServerSession session = new GearmanJobServerSession(conn);
if (ioAvailable == null) {
try {
ioAvailable = Selector.open();
} catch (IOException ioe) {
LOG.warn("Failed to connect to job server " + conn + ".", ioe);
return false;
}
}
try {
session.initSession(ioAvailable, this);
} catch (IOException ioe) {
LOG.warn("Failed to initialize session with job server " + conn + ".", ioe);
return false;
}
SelectionKey key = session.getSelectionKey();
if (key == null) {
String msg =
"Session "
+ session
+ " has a null "
+ "selection key. Server will not be added to worker.";
LOG.warn(msg);
throw new IllegalStateException(msg);
}
sessionMap.put(key, session);
GearmanPacket p =
new GearmanPacketImpl(
GearmanPacketMagic.REQ, GearmanPacketType.SET_CLIENT_ID, ByteUtils.toUTF8Bytes(id));
session.submitTask(new GearmanTask(p));
for (FunctionDefinition def : functionMap.values()) {
p = generateCanDoPacket(def);
session.submitTask(new GearmanTask(p)); // NOPMD
}
p = new GearmanPacketImpl(GearmanPacketMagic.REQ, getGrabJobPacketType(), new byte[0]);
GearmanTask gsr = new GearmanTask(new GrabJobEventHandler(session), p);
taskMap.put(session, gsr);
session.submitTask(gsr);
LOG.debug("Added server " + conn + " to worker " + this);
return true;
}
private void shutDownSession(GearmanJobServerSession s) {
if (s.isInitialized()) {
SelectionKey k = s.getSelectionKey();
if (k != null) {
sessionsMap.remove(k);
k.cancel();
}
s.closeSession();
}
sessionJobsMap.remove(s);
}
public boolean addJobServer(GearmanJobServerConnection newconn, boolean serverForwardsExceptions)
throws IllegalArgumentException, IllegalStateException {
// TODO remove this restriction
if (!(newconn instanceof GearmanNIOJobServerConnection)) {
throw new IllegalArgumentException(
"Client currently only "
+ "supports "
+ GearmanNIOJobServerConnection.class.getName()
+ " connections.");
}
GearmanNIOJobServerConnection conn = (GearmanNIOJobServerConnection) newconn;
if (!runState.equals(state.RUNNING)) {
throw new RejectedExecutionException("Client has been shutdown");
}
GearmanJobServerSession session = new GearmanJobServerSession(conn);
if (sessionsMap.values().contains(session)) {
LOG.debug(
"The server "
+ newconn
+ " was previously "
+ "added to the client. Ignoring add request.");
return true;
}
try {
if (ioAvailable == null) {
ioAvailable = Selector.open();
}
session.initSession(ioAvailable, this);
SelectionKey key = session.getSelectionKey();
sessionsMap.put(key, session);
} catch (IOException ioe) {
LOG.warn("Failed to connect to job server " + newconn + ".", ioe);
return false;
}
if (serverForwardsExceptions && !setForwardExceptions(session)) {
return false;
}
sessionJobsMap.put(session, new HashMap<JobHandle, GearmanJobImpl>());
LOG.info("Added connection " + conn + " to client " + this);
return true;
}
private GearmanJobServerSession getSessionForTask() throws IOException {
if (sessionsMap.values().isEmpty()) {
throw new IOException("No servers registered with client");
}
ArrayList<GearmanJobServerSession> sessions = new ArrayList<GearmanJobServerSession>();
sessions.addAll(sessionsMap.values());
Random rand = new Random(System.currentTimeMillis());
int s = rand.nextInt(sessions.size());
GearmanJobServerSession session = sessions.get(s);
IOException ioe = new IOException("No servers available for client");
for (int i = 0; i < sessions.size(); i++) {
if (!session.isInitialized()) {
try {
session.initSession(ioAvailable, this);
sessionsMap.put(session.getSelectionKey(), session);
} catch (Exception e) {
if (sessions.size() > 1) {
// try next one
int prev = s;
s = (s + 1) % sessions.size();
session = sessions.get(s);
LOG.warn(
"Got exception attempting to retrieve "
+ "session for task. Try next server at "
+ "pos={}, previous pos={}",
s,
prev);
continue;
} else {
break;
}
}
}
return session;
}
throw ioe;
}
public void work() {
if (!state.equals(State.IDLE)) {
throw new IllegalStateException(
"Can not call work while worker " + "is running or shutting down");
}
state = State.RUNNING;
// a map keeping track of sessions with connection errors
// (to avoid printing an error about them in every reconnect attempt)
Map<GearmanJobServerSession, Boolean> havingConnectionError =
new HashMap<GearmanJobServerSession, Boolean>();
while (isRunning()) {
// look for sessions which have been disconnected and attempt to reconnect.
for (Iterator<GearmanJobServerSession> iter = sessionMap.values().iterator();
iter.hasNext(); ) {
GearmanJobServerSession sess = iter.next();
if (!sess.isInitialized()) {
try {
// reconnect, unregister old selection key and register new one
SelectionKey oldKey = sess.isInitialized() ? sess.getSelectionKey() : null;
sess.initSession(ioAvailable, this);
if (oldKey != null) {
iter.remove();
}
sessionMap.put(sess.getSelectionKey(), sess);
// register all functions with the newly reconnected server
for (FunctionDefinition d : functionMap.values()) {
GearmanTask gsr = new GearmanTask(null, generateCanDoPacket(d));
sess.submitTask(gsr);
}
GearmanPacket p =
new GearmanPacketImpl(
GearmanPacketMagic.REQ,
GearmanPacketType.SET_CLIENT_ID,
ByteUtils.toUTF8Bytes(id));
sess.submitTask(new GearmanTask(p));
GearmanTask sessTask =
new GearmanTask(
new GrabJobEventHandler(sess),
new GearmanPacketImpl(
GearmanPacketMagic.REQ, getGrabJobPacketType(), new byte[0]));
sess.submitTask(sessTask);
sess.driveSessionIO();
// log reconnection message
if (havingConnectionError.get(sess)) {
LOG.info("Re-established connection to " + sess.getConnection().toString());
}
havingConnectionError.put(sess, false);
} catch (IOException e) {
if (!havingConnectionError.get(sess)) {
LOG.warn("Error connecting to " + sess + ", will keep trying..");
}
havingConnectionError.put(sess, true);
try {
Thread.sleep(50);
} catch (InterruptedException e1) {
}
}
} else {
havingConnectionError.put(sess, false);
}
}
for (GearmanJobServerSession sess : sessionMap.values()) {
// if still disconnected, skip
if (!sess.isInitialized()) {
continue;
}
int interestOps = SelectionKey.OP_READ;
if (sess.sessionHasDataToWrite()) {
interestOps |= SelectionKey.OP_WRITE;
}
sess.getSelectionKey().interestOps(interestOps);
}
try {
ioAvailable.select(1);
} catch (IOException io) {
LOG.warn("Receieved IOException while" + " selecting for IO", io);
}
for (SelectionKey key : ioAvailable.selectedKeys()) {
GearmanJobServerSession sess = sessionMap.get(key);
if (sess == null) {
LOG.warn("Worker does not have " + "session for key " + key);
continue;
}
if (!sess.isInitialized()) {
continue;
}
try {
GearmanTask sessTask = taskMap.get(sess);
if (sessTask == null) {
sessTask =
new GearmanTask( // NOPMD
new GrabJobEventHandler(sess),
new GearmanPacketImpl(
GearmanPacketMagic.REQ, getGrabJobPacketType(), new byte[0]));
taskMap.put(sess, sessTask);
sess.submitTask(sessTask);
LOG.debug(
"Worker: "
+ this
+ " submitted a "
+ sessTask.getRequestPacket().getPacketType()
+ " to session: "
+ sess);
}
sess.driveSessionIO();
// For the time being we will execute the jobs synchronously
// in the future, I expect to change this.
if (!functionList.isEmpty()) {
GearmanFunction fun = functionList.remove();
submitFunction(fun);
statistics();
}
} catch (IOException ioe) {
LOG.warn("Received IOException while driving" + " IO on session " + sess, ioe);
sess.closeSession();
continue;
}
}
}
shutDownWorker(true);
}