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Hazelcast in the master node cannot communicate to another node in a different VM

My application runs in two different VMs and they have the same configuration. When the second node runs up after the first one, Hazelcast members in different servers join, but they cannot initiate the communication.
App uses TCP/IP for the discovery and there are also network interfaces configured.
Here is my config code:
#Bean
public NetworkConfig networkConfig(final Config hazelCastConfiguration) throws UnknownHostException {
final NetworkConfig network = hazelCastConfiguration.getNetworkConfig();
network.setPort(port);
network.setPortAutoIncrement(true);
final JoinConfig join = network.getJoin();
final MulticastConfig multicast = join.getMulticastConfig();
multicast.setEnabled(false);
final TcpIpConfig tcpIp = join.getTcpIpConfig();
tcpIp.setEnabled(true);
for (final String member : members) {
final InetAddress[] addresses = MoreObjects.firstNonNull(
InetAddress.getAllByName(member),
new InetAddress[0]);
for (final InetAddress addr : addresses) {
final String hostAddress = addr.getHostAddress();
tcpIp.addMember(hostAddress);
log.info("[Hazelcast] New Member: " + hostAddress);
}
}
return network;
}
And:
final InterfacesConfig interfacesConfig = network.getInterfaces();
interfacesConfig.setEnabled(true);
for (final String networkInterface : interfaces) {
log.info("[Hazelcast] Interface: " + networkInterface);
network.getInterfaces().addInterface(networkInterface);
log.info("[Hazelcast] Interface: " + network.getInterfaces());
}
Because the application runs in a different server, I set up members and the interface as follows:
"HOST1IP" and "HOST2IP"
When I run the apps, I get the following logs:
Members {size:2, ver:6} [
Member ["HOSTIP1"]:5702 - 6a356dc6-4b16-49dd-8cb5-a7df62f7c2d2 this
Member ["HOSTIP2"]:5702 - 015b5b34-657f-4b38-8b67-17810777ac2e
]
Members join, and then:
com.hazelcast.nio.tcp.TcpIpConnection
: ["HOSTIP1"]:5702 [example-app] [3.11.4] Initialized new cluster connection between /"HOSTIP2":53725 and /"HOSTIP2":5701
I am expecting to initiate a connection to "HOSTIP2":5702 but it doesn't.
Any ideas, or help very appreciated.

Angular 8 socket.io-client 2.2.0 and Java netty-socket.io message not being received?

I am using netty-socket.io and I implemented the server like the demo.
I receive onConnect event both on server and client, but when I sent a message {message: message} I don't get anything on the server event though I see the message being sent in the network tab.
Configuration config = new Configuration();
config.setHostname("localhost");
config.setPort(9092);
final SocketIOServer server = new SocketIOServer(config);
server.addConnectListener(socketIOClient -> System.out.println("Connection test"));
server.addEventListener("messageevent", MessageEventObject.class, new DataListener<MessageEventObject>() {
#Override
public void onData(SocketIOClient socketIOClient, MessageEventObject messageEventObject, AckRequest ackRequest) throws Exception {
System.out.println("message received!");
}
});
server.start();
My MessageEventObject has String message property, constructor getters and setters, looking the same as client-sided.
And this is my websocket service client-sided:
export class WebsocketService {
private socket;
private subject = new Subject < any > ();
constructor() {
console.log('test!');
}
public connect(host: string, port: number) {
this.socket = io(`http://${host}:${port}`, {
'reconnection': false
});
this.socket.on('connect', this.onConnected);
this.socket.on('connect_error', this.onConnectionFailure);
}
public getConnectionStateUpdate(): Observable < any > {
return this.subject.asObservable();
}
public sendMessage(message: string) {
console.log('test');
this.socket.emit('messageevent', {
message: message
});
}
private onConnected = () => {
this.subject.next({
connected: true
});
}
private onConnectionFailure = () => {
this.subject.next({
connected: false
});
}
}
Is there anything that I did wrong?

I would love to answer my own question after tons of debugging and breaking my head, my laziness to use Engine IO with tomcat or jetty, and just wanting to use that awesome netty package which does not require any servlets, I tried to fix it and figure out.
At first I thought it was the client's protocol version, so I used the exact same client as the demo shows on their github page here but that didn't work so the problem is server-sided.
It appears that your object (MessageEventObject) must have a default empty constructor aswell in addition to your other constructors, probably because netty tries to build an empty object and it fails which causes an exception that you don't see.

How to capture the server used to fulfill a request when incoming traffic is using Load Balancer URL?

I have a Spring Boot Java REST application with many APIs exposed to our clients and UI. I was tasked with implementing a Transaction logging framework that will capture the incoming transactions along with the response we send.
I have this working with Spring AOP and an Around inspect and I'm currently utilizing the HttpServletRequest and HttpServletResponse objects to obtain a lot of the data I need.
From my local system I am not having any issues capturing the server used since I'm connecting to my system directly. However, once I deployed my code I saw that the load balancer URL was being captured instead of the actual server name.
I am also using Eureka to discover the API by name as it's only a single application running on HAProxy.
Imagine this flow:
/*
UI -> https://my-lb-url/service-sidecar/createUser
HAProxy directs traffic to -> my-lb-url/service-sidecar/ to one of below:
my-server-1:12345
my-server-2:12345
my-server-3:12345
Goal : http://my-server-1:1235/createUser
Actual: https://my-lb-url/createUser
Here is the code I am using to get the incoming URL.
String url = httpRequest.getRequestURL().toString();
if(httpRequest.getQueryString() != null){
transaction.setApi(url + "?" + httpRequest.getQueryString());
} else {
transaction.setApi(url);
}
Note:
I am not as familiar with HAProxy/Eurkea/etc. as I would like to be. If something stated above seems off or wrong then I apologize. Our system admin configured those and locked the developers out.
UPDATE
This is the new code I am using to construct the Request URL, but I am still seeing the output the same.
// Utility Class
public static String constructRequestURL(HttpServletRequest httpRequest) {
StringBuilder url = new StringBuilder(httpRequest.getScheme());
url.append("://").append(httpRequest.getServerName());
int port = httpRequest.getServerPort();
if(port != 80 && port != 443) {
url.append(":").append(port);
}
url.append(httpRequest.getContextPath()).append(httpRequest.getServletPath());
if(httpRequest.getPathInfo() != null) {
url.append(httpRequest.getPathInfo());
}
if(httpRequest.getQueryString() != null) {
url.append("?").append(httpRequest.getQueryString());
}
return url.toString();
}
// Service Class
transaction.setApi(CommonUtil.constructRequestURL(httpRequest));

I found a solution to this issue, but it's not the cleanest route and I would gladly take another suggestion if possible.
I am autowiring the port number from my application.yml.
I am running the "hostname" command on the Linux server that is hosting the application to determine the server fulfilling the request.
Now the URL stored in the Transaction Logs is accurate.
--
#Autowired
private int serverPort;
/*
* ...
*/
private String constructRequestURL(HttpServletRequest httpRequest) {
StringBuilder url = new StringBuilder(httpRequest.getScheme())
.append("://").append(findHostnameFromServer()).append(":").append(serverPort)
.append(httpRequest.getContextPath()).append(httpRequest.getServletPath());
if(httpRequest.getPathInfo() != null) {
url.append(httpRequest.getPathInfo());
}
if(httpRequest.getQueryString() != null) {
url.append("?").append(httpRequest.getQueryString());
}
return url.toString();
}
private String findHostnameFromServer(){
String hostname = null;
LOGGER.info("Attempting to Find Hostname from Server...");
try {
Process process = Runtime.getRuntime().exec(new String[]{"hostname"});
try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
hostname = reader.readLine();
}
} catch (IOException e) {
LOGGER.error(CommonUtil.ERROR, e);
}
LOGGER.info("Found Hostname: {}", hostname);
return hostname;
}

How to determine when message was sent in Akka

I am wondering if there is the possibility to know when a message has been delivered. Since I want to shutdown the actorsystem right afterwards. The code below connects to a remote actor and then sends a message. But in some cases the local actorsystem seems to be shut down too early.
ActorSystem system = ActorSystem.create("Test", config.getConfig("webbackend"));
ActorSelection communicator = system.actorSelection("akka.tcp://Midas#127.0.0.1:2555/user/Communicator");
communicator.tell(new TimerTransmissionCmd(channel.getId()), ActorRef.noSender());
//system.shutdown();

Try adding this code after send the message:
Boolean wasProcessed = (Integer)Await.result(Patterns.ask(communicator, new ResultClass(), 5000),
Duration.create(5000, TimeUnit.MILLISECONDS));
if(wasProcessed){
actorSystem.shutdown();
}
You also have to add this in your Actor class:
private boolean wasProcessed = false;
#Override
public void onReceive(Object messageReceived) throws Exception {
if (messageReceived instanceof ResultClass) {
this.workerActor1.tell(wasProcessed, getSender());
} else {
//Put your process code here
wasProcessed = true;
}
}
But I recommend you configure a prudential timeout and after that always shutdown the system.

Jini/JavaSpaces discovery error

On this article: http://java.sun.com/developer/technicalArticles/tools/JavaSpaces/ is a tutorial how to run JavaSpaces client. I wrote these classes in Eclipse, started Launch-All script and Run example. It works.
After that I exported these classes into executable jar (JavaSpaceClient.jar) and tried that jar with following command:
java -jar JavaSpaceClient.jar
It works fine, gives me result:
Searching for a JavaSpace...
A JavaSpace has been discovered.
Writing a message into the space...
Reading a message from the space...
The message read is: Здраво JavaSpace свете!
My problem is when I move this jar file on my other LAN computer, it shows me error when I type same command. Here is error:
cica#cica-System-Name:~/Desktop$ java -jar JavaSpaceClient.jar
Searching for a JavaSpace...
Jul 27, 2011 11:20:54 PM net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask run
INFO: exception occurred during unicast discovery to biske-Inspiron-1525:4160 with constraints InvocationConstraints[reqs: {}, prefs: {}]
java.net.UnknownHostException: biske-Inspiron-1525
at java.net.AbstractPlainSocketImpl.connect(AbstractPlainSocketImpl.java:175)
at java.net.SocksSocketImpl.connect(SocksSocketImpl.java:384)
at java.net.Socket.connect(Socket.java:546)
at java.net.Socket.connect(Socket.java:495)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getSingleResponse(MultiIPDiscovery.java:134)
at com.sun.jini.discovery.internal.MultiIPDiscovery.getResponse(MultiIPDiscovery.java:75)
at net.jini.discovery.LookupDiscovery$UnicastDiscoveryTask.run(LookupDiscovery.java:1756)
at net.jini.discovery.LookupDiscovery$DecodeAnnouncementTask.run(LookupDiscovery.java:1599)
at com.sun.jini.thread.TaskManager$TaskThread.run(TaskManager.java:331)
I just writes "Searching for JavaSpace..." and after a while prints these error messages.
Can someone help me with this error?
EDIT:
For discovery I am using LookupDiscovery class I've found on Internet:
import java.io.IOException;
import java.rmi.RemoteException;
import net.jini.core.lookup.ServiceRegistrar;
import net.jini.core.lookup.ServiceTemplate;
import net.jini.discovery.LookupDiscovery;
import net.jini.discovery.DiscoveryListener;
import net.jini.discovery.DiscoveryEvent;
/**
A class which supports a simple JINI multicast lookup. It doesn't register
with any ServiceRegistrars it simply interrogates each one that's
discovered for a ServiceItem associated with the passed interface class.
i.e. The service needs to already have registered because we won't notice
new arrivals. [ServiceRegistrar is the interface implemented by JINI
lookup services].
#todo Be more dynamic in our lookups - see above
#author Dan Creswell (dan#dancres.org)
#version 1.00, 7/9/2003
*/
public class Lookup implements DiscoveryListener {
private ServiceTemplate theTemplate;
private LookupDiscovery theDiscoverer;
private Object theProxy;
/**
#param aServiceInterface the class of the type of service you are
looking for. Class is usually an interface class.
*/
public Lookup(Class aServiceInterface) {
Class[] myServiceTypes = new Class[] {aServiceInterface};
theTemplate = new ServiceTemplate(null, myServiceTypes, null);
}
/**
Having created a Lookup (which means it now knows what type of service
you require), invoke this method to attempt to locate a service
of that type. The result should be cast to the interface of the
service you originally specified to the constructor.
#return proxy for the service type you requested - could be an rmi
stub or an intelligent proxy.
*/
Object getService() {
synchronized(this) {
if (theDiscoverer == null) {
try {
theDiscoverer =
new LookupDiscovery(LookupDiscovery.ALL_GROUPS);
theDiscoverer.addDiscoveryListener(this);
} catch (IOException anIOE) {
System.err.println("Failed to init lookup");
anIOE.printStackTrace(System.err);
}
}
}
return waitForProxy();
}
/**
Location of a service causes the creation of some threads. Call this
method to shut those threads down either before exiting or after a
proxy has been returned from getService().
*/
void terminate() {
synchronized(this) {
if (theDiscoverer != null)
theDiscoverer.terminate();
}
}
/**
Caller of getService ends up here, blocked until we find a proxy.
#return the newly downloaded proxy
*/
private Object waitForProxy() {
synchronized(this) {
while (theProxy == null) {
try {
wait();
} catch (InterruptedException anIE) {
}
}
return theProxy;
}
}
/**
Invoked to inform a blocked client waiting in waitForProxy that
one is now available.
#param aProxy the newly downloaded proxy
*/
private void signalGotProxy(Object aProxy) {
synchronized(this) {
if (theProxy == null) {
theProxy = aProxy;
notify();
}
}
}
/**
Everytime a new ServiceRegistrar is found, we will be called back on
this interface with a reference to it. We then ask it for a service
instance of the type specified in our constructor.
*/
public void discovered(DiscoveryEvent anEvent) {
synchronized(this) {
if (theProxy != null)
return;
}
ServiceRegistrar[] myRegs = anEvent.getRegistrars();
for (int i = 0; i < myRegs.length; i++) {
ServiceRegistrar myReg = myRegs[i];
Object myProxy = null;
try {
myProxy = myReg.lookup(theTemplate);
if (myProxy != null) {
signalGotProxy(myProxy);
break;
}
} catch (RemoteException anRE) {
System.err.println("ServiceRegistrar barfed");
anRE.printStackTrace(System.err);
}
}
}
/**
When a ServiceRegistrar "disappears" due to network partition etc.
we will be advised via a call to this method - as we only care about
new ServiceRegistrars, we do nothing here.
*/
public void discarded(DiscoveryEvent anEvent) {
}
}
My client program tries simply to search for JavaSpaces service write MessageEntry into and then retrieves message and prints it out. Here is client program:
import net.jini.space.JavaSpace;
public class SpaceClient {
public static void main(String argv[]) {
try {
MessageEntry msg = new MessageEntry();
msg.content = "Hello JavaSpaces wordls!";
System.out.println("Searching for JavaSpaces...");
Lookup finder = new Lookup(JavaSpace.class);
JavaSpace space = (JavaSpace) finder.getService();
System.out.println("JavaSpaces discovered.");
System.out.println("Writing into JavaSpaces...");
space.write(msg, null, 60*60*1000);
MessageEntry template = new MessageEntry();
System.out.println("Reading message from JavaSpaces...");
MessageEntry result = (MessageEntry) space.read(template, null, Long.MAX_VALUE);
System.out.println("Message: "+result.content);
} catch(Exception e) {
e.printStackTrace();
}
}
}
And of course this is MessageEntry class:
import net.jini.core.entry.*;
public class MessageEntry implements Entry {
public String content;
public MessageEntry() {
}
public MessageEntry(String content) {
this.content = content;
}
public String toString() {
return "MessageContent: " + content;
}
}
EDIT2:
I did discovery on two Windows computers.
After that I tried Windows - Ubuntu combiantion and it doesn't work. Maybe there are some network problems? When I ping each another everything is ok. Maybe there are some DNS issues on Ubuntu..
EDIT3:
Windows - Ubuntu combination works if JavaSpaces service is started up on Windows and client program is on Ubuntu. When I try to do reverse, to run JavaSpaces service on Ubuntu and run client on Windows error occurs.
Obviously there is some problem with Ubuntu. Ubuntu has installed OpenJDK installed by default. I installed Oracle JDK, and set JAVA_HOME and put JAVA_HOME/bin into PATH variable. I wonder maybe there is some problem with different versions of Java, maybe I am not using right one.

It is possible that the service registrar that you are running (on host biske-Inspiron-1525 at port 4160), is discovering it's hostname incorrectly (without domain name) and is therefore sending out the announcements with a short hostname. Therefore, after discovering the service registrar, it is possible that subsequently the client is trying to make a connection to the service registrar it cannot resolve the hostname if it is on a different domain.
To ensure that the service registrar is running with the correct hostname, try starting it with the following command line attribute:
-Dcom.sun.jini.reggie.unicastDiscoveryHost="biske-Inspiron-1525.and.its.domain"

It appears that you are doing unicast discovery to a specific host and port and that you can't look up that host.
Assuming you can resolve the name biske-Inspiron-1525 with DNS try removing the ":4160" part and see if the unicast lookup succeeds then.
Here is an example of the code I use to look up a service. It's a bit more complicated because I implement ServiceDiscoveryListener and handle service discovery that way. I actually keep a list of services and dynamically switch between then when one fails but I stripped that part out of the example. I am also using the Configuration part of Jini which I'll explain afterwards. The service interface I am using here is called "TheService":
public class JiniClient implements ServiceDiscoveryListener {
private TheService service = null;
private Class[] serviceClasses;
private ServiceTemplate serviceTemplate;
public JiniClient(String[] configFiles) throws ConfigurationException {
Configuration config = ConfigurationProvider.getInstance(configFiles,
getClass().getClassLoader());
// Set the security manager
System.setSecurityManager(new RMISecurityManager());
// Define the service we are interested in.
serviceClasses = new Class[] {TheService.class};
serviceTemplate = new ServiceTemplate(null, serviceClasses, null);
// Build a cache of all discovered services and monitor changes
ServiceDiscoveryManager serviceMgr = null;
DiscoveryManagement mgr = null;
try {
mgr = (DiscoveryManagement)config.getEntry(
getClass().getName(), // component
"discoveryManager", // name
DiscoveryManagement.class); // type
if (null == mgr) {
throw new ConfigurationException("entry for component " +
getClass().getName() + " name " +
"discoveryManager must be non-null");
}
} catch (Exception e) {
/* This will catch both NoSuchEntryException and
* ConfigurationException. Putting them both
* below just to make that clear.
*/
if( (e instanceof NoSuchEntryException) ||
(e instanceof ConfigurationException)) {
// default value
try {
System.err.println("Warning, using default multicast discover.");
mgr = new LookupDiscoveryManager(LookupDiscovery.ALL_GROUPS,
null, // unicast locators
null); // DiscoveryListener
} catch(IOException ioe) {
e.printStackTrace();
throw new RuntimeException("Unable to create lookup discovery manager: " + e.toString());
}
}
}
try {
serviceMgr = new ServiceDiscoveryManager(mgr, new LeaseRenewalManager());
} catch (IOException e) {
e.printStackTrace();
throw new RuntimeException("Unable to create service discovery manager: " + e.toString());
}
try {
serviceMgr.createLookupCache(serviceTemplate,
null, // no filter
this); // listener
} catch(Exception e) {
e.printStackTrace();
throw new RuntimeException("Unable to create serviceCache: " + e.getMessage());
}
}
public void serviceAdded(ServiceDiscoveryEvent evt) {
/* Called when a service is discovered */
ServiceItem postItem = evt.getPostEventServiceItem();
//System.out.println("Service appeared: " +
// postItem.service.getClass().toString());
if(postItem.service instanceof TheService) {
/* You may be looking for multiple services.
* The serviceAdded method will be called for each
* so you can use instanceof to figure out if
* this is the one you want.
*/
service = (TheService)postItem.service;
}
}
public void serviceRemoved(ServiceDiscoveryEvent evt) {
/* This notifies you of when a service goes away.
* You could keep a list of services and then remove this
* service from the list.
*/
}
public void serviceChanged(ServiceDiscoveryEvent evt) {
/* Likewise, this is called when a service changes in some way. */
}
The Configuration system allows you to dynamically configure the discovery method so you can switch to discover specific unicast systems or multicast without changing the app. Here is an example of a unicast discovery configuration file that you could pass to the above objects constructor:
import net.jini.core.discovery.LookupLocator;
import net.jini.discovery.LookupDiscoveryManager;
import net.jini.discovery.LookupDiscovery;
com.company.JiniClient {
discoveryManager = new LookupDiscoveryManager(
LookupDiscovery.ALL_GROUPS,
new LookupLocator[] { new LookupLocator("jini://biske-Inspiron-1525.mycompany.com")},
null,
this); // the current config
}

I found solution! That was dns issue. On Ubuntu my /etc/hosts file was:
192.168.1.3 biske-Inspiron-1525 # Added by NetworkManager
127.0.0.1 localhost.localdomain localhost
::1 biske-Inspiron-1525 localhost6.localdomain6 localhost6
127.0.1.1 biske-Inspiron-1525
# The following lines are desirable for IPv6 capable hosts
::1 localhost ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
I've just removed line 127.0.1.1 biske-Inspiron-1525 and now it works fine.
Little thing was destroyed million of my nerves :)