/**
* Registers the slave server with the coordinator
*
* @param masterHostName
* @param servr KVServer used by this slave server (contains the hostName and a random port)
* @throws UnknownHostException
* @throws IOException
* @throws KVException
*/
public void registerWithMaster(String masterHostName, SocketServer server)
throws UnknownHostException, IOException, KVException {
AutoGrader.agRegistrationStart(slaveID);
Socket master = new Socket(masterHostName, 9090);
KVMessage regMessage =
new KVMessage("register", slaveID + "@" + server.getHostname() + ":" + server.getPort());
regMessage.sendMessage(master);
master.close();
AutoGrader.agRegistrationStart(slaveID);
}
/**
* Load log and rebuild KVServer by iterating over log entries. You do not need to restore the
* previous cache state (i.e. ignore GETS).
*
* @throws KVException if an error occurs in KVServer (though we expect none)
*/
public void rebuildServer() throws KVException {
KVMessage interruptedTPCOperation = null;
loadFromDisk();
for (int i = 0; i < entries.size(); i++) {
// System.out.println("rebuild server " + i);
KVMessage entry = entries.get(i);
String msgType = entry.getMsgType();
if (msgType.equals("putreq") || msgType.equals("delreq")) {
interruptedTPCOperation = entry;
continue;
}
if (msgType.equals("commit") && interruptedTPCOperation != null) {
if (interruptedTPCOperation.getMsgType().equals("delreq")) {
kvServer.del(interruptedTPCOperation.getKey());
} else if (interruptedTPCOperation.getMsgType().equals("putreq")) {
kvServer.put(interruptedTPCOperation.getKey(), interruptedTPCOperation.getValue());
}
interruptedTPCOperation = null;
} else if (msgType.equals("abort")) {
interruptedTPCOperation = null;
}
}
}
@Override
public void run() {
// Receive message from client
// Implement me
KVMessage msg = null;
// Parse the message and do stuff
String key = msg.getKey();
if (msg.getMsgType().equals("putreq")) {
handlePut(msg, key);
} else if (msg.getMsgType().equals("getreq")) {
handleGet(msg, key);
} else if (msg.getMsgType().equals("delreq")) {
handleDel(msg, key);
} else if (msg.getMsgType().equals("ignoreNext")) {
// Set ignoreNext to true. PUT and DEL handlers know what to do.
// Implement me
// Send back an acknowledgment
// Implement me
} else if (msg.getMsgType().equals("commit") || msg.getMsgType().equals("abort")) {
// Check in TPCLog for the case when SlaveServer is restarted
// Implement me
handleMasterResponse(msg, originalMessage, aborted);
// Reset state
// Implement me
}
// Finally, close the connection
closeConn();
}
/**
* Load log and rebuild KVServer by iterating over log entries. You do not need to restore the
* previous cache state (i.e. ignore GETS).
*
* @throws KVException if an error occurs in KVServer (though we expect none)
*/
public void rebuildServer() throws KVException {
// implement me
try {
loadFromDisk();
kvServer.wipeEverything();
KVMessage request = null;
for (KVMessage log : entries) {
if (log.getMsgType().equals(PUT_REQ) || log.getMsgType().equals(DEL_REQ)) {
request = log;
} else if (log.getMsgType().equals(COMMIT)) {
if (request == null) {
// Do nothing. If reached here, repeated COMMIT
continue;
} else if (request.getMsgType().equals(PUT_REQ)) {
kvServer.put(request.getKey(), request.getValue());
} else if (request.getMsgType().equals(DEL_REQ)) {
kvServer.del(request.getKey());
}
} else if (log.getMsgType().equals(ABORT)) {
request = null;
}
}
} catch (Exception e) {
// throw new KVException("Error: Rebuild failed");
}
}
