RMI Registry leaves thread running

I've searched the postings about this topic and none of them have been helpful. I create an RMI registry at port 1099 in my app, use it, and then try to shut it down, but it leaves a thread running.
The following sample code shows what my code does (in a condensed form):
Registry registry = LocateRegistry.createRegistry(1099);
Communicator c = new CommunicatorImpl();
registry.rebind("//localhost/remoteserver", c );
Naming.rebind("rmi://localhost:1099/TriggerService", c);
registry.unbind("//localhost/remoteserver");
Naming.unbind("rmi://localhost:1099/TriggerService");
boolean b = UnicastRemoteObject.unexportObject(registry, true);
System.err.println( "unexported: "+b );When I run this code in Eclipse and the code exits, I still have a process running that was spawned by "LocateRegistry.createRegistry(1099)", but I can't figure out how to get a handle for it within my program, so that I can kill it. I've read that it will end when the JVM ends, but the RMI portion of my app is only a small part and I need the rest of it to keep running. Is there a way to stop this thread?
Thanks,
Tony

Well I only see 'createRegistry' and 'getRegistry' I don't see any 'destroyRegistry' methods. So I don't know.
What I used to do back in the day was to use Runtime to start an external process for processes that I needed to kill later on. So perhaps you can use the runtime to start the registry from the command line so to speak. Then hold a reference to the returned process. Then you can kill that process when you want the registry to die. In this case you will for sure be creating a new 'jvm' for the registry to run within. (if the registry is a java program)
Otherwise I have no idea why you would be seeing an extra java process. If you run the eclipse debugger, the debugger should not exit until the whole process is done. Even when the program is done, the debugger will still be 'live' and you can push the stop button to stop the whole launched process.

Similar Messages

Run rmi registry in executable

Hi all,
I've created a jar executable for an application I wrote. I have two questions if anyone can help me out with either.
1. Is there anyway to have it run my rmi registry along with the jar executable so I don't have to run it seperate?
2. Is there anyway that I can make a .exe executable for a user that doesn't have jre for free? I've found some programs that will do it for me, but I have to purchase them. I'd also like to avoid converting all my code into another language first.
Any help would be appreciated. Thanks
Leon

1. java.rmi.registry.LocateRegistry.createRegistry().
2. There is GCJ, but I don't recommend it.

RMI :- how to know that rmi registry is running or not using java code

hi
I want to know that how to check wather rmi registry is running or not by program in java
plz any one reply

Simple method - try to connect to it and see if you get an exception.
Since the registry can be running on a remote machine, the only simple way
is to try connecting.
If the registry is running on a local machine you can also use OS tools (like "ps" on unix) to check whether the process is running, or network tools (e.g. netstat) to check whether it's listening on its TCP/IP port.
Genady

Bind to RMI registry on remote host

Is it possible to bing to a RMI registry on remote host. I get a Access exception when I try it. Is there is any work around for this?
Any help will be greatly appreciated.
Thanks
R

:Like I say, JINI uses a different model to RMI, and you can probably have a look at the forum for that here.
but a way around it is to create a server which listens for requests, accepts a remote object and a remote object name, and binds those into the registry on which its running - remember that the restriction only applies to registering objects, not to looking them up, so, once the object is registered on the remote host, it can be retrieved quite easily.
This of course leaves the problem of exception ahandling aside, but I trust the problems there are obvious

RMI Registry fail to initiate

Hi Guruz,
Let me describe the problem..
I have 2 apps running on tomcat server. Both the apps initiates RMI server and then regiter the object on RMI registry. If I deploy both the app on a single web server ( Tomcat ) and start the server, it successfully create and register the rmi object but the subsequent app when attempts to register their object, it crashes.
I am pasting the snippet of code that initiate rmi regitry.I am using the same code to initiate rmi registry with the same port.
try{
//Start the RMI registry
registry = LocateRegistry.createRegistry(ServiceProperties.rmiServerBindPort);
catch(RemoteException re){
try {
registry = LocateRegistry.getRegistry(ServiceProperties.rmiAppHost, ServiceProperties.rmiServerBindPort);
} catch (RemoteException remE) {
log.error("could not initialize RMI registry", remE);
throw remE;
Here's the error that is being thrown if subscequent app try to initiate rmi registry. Both the apps have same security policy present. Please give you input why this is happening.
ERROR : remote exception.....Failed to bind to RMI registry : RemoteException occurred in server thread; nested exception is:
java.rmi.UnmarshalException: error unmarshalling arguments; nested exception is:
java.lang.ClassNotFoundException: com.abc.efg.hij.RMIListenerImpl_Stub (no security manager: RMI class loader disabled)
Regards,
Kashif

You can only run one rmi on a single port. You are going to have to use different machines or different ports. How would java be able to distinguish which registry to use if this were possible?

RMI registry reset

Hi there,
I'm writing a RMI application where I need to clean up the RMI registry as soon as the ip address of the server machine changes.
Let's say that I want to make an object (class Obj) accessible from a RMI client through the following code:
Obj obj = new Obj();
UnicastRemoteObject.exportObject(obj,RMIPort); //export the new object
registry = LocateRegistry.createRegistry(RMIPort); //Create a new registry
registry.rebind("myObject", obj); //Bind the object to the registryOnce I detect an ip change I need to clean up the register and I need to publish a new Obj object on it. The new object has to accessible from a RMI client instead of the previous. I tried something like:
UnicastRemoteObject.unexportObject(obj,RMIPort); //unexport the old object
Obj obj2 = new Obj(); //Create a new object
UnicastRemoteObject.exportObject(obj2,RMIPort); //export the new object
registry = LocateRegistry.getRegistry(RMI_PORT);
registry.rebind("myObject", obj2); //Bind the new object to the registry with the same name "myObject"But when the last line of code is executed, an exception "java.rmi.UnmarshalException: Error Unmarshaling return header" is thrown.
Do you guys have any suggestions?

This is the complete stack trace:
java.rmi.UnmarshalException: Error unmarshaling return header; nested exception is:
     java.net.SocketException: Connection reset
     at sun.rmi.transport.StreamRemoteCall.executeCall(Unknown Source)
     at sun.rmi.server.UnicastRef.invoke(Unknown Source)
     at sun.rmi.registry.RegistryImpl_Stub.rebind(Unknown Source)
     at pack.net.stud.Stud.reset(Stud.java:184)
     at pack.net.connectors.IPChangeDetector.run(IPChangeDetector.java:74)
     at java.lang.Thread.run(Unknown Source)
Caused by: java.net.SocketException: Connection reset
     at java.net.SocketInputStream.read(Unknown Source)
     at java.io.BufferedInputStream.fill(Unknown Source)
     at java.io.BufferedInputStream.read(Unknown Source)
     at java.io.DataInputStream.readByte(Unknown Source)
     ... 6 moreThanks
Francesco

Is the RMI registry "process-atomic"?

Hi,
Sorry if this is a really stupid question, and I have really tried to find this out on my own.
When I say "process" I mean Process, as opposed to Thread.
What I mean is, if one Process calls Registry.bind( String, Remote ), can we be sure that another Process which does the same thing one nanosecond later will get an AlreadyBoundException if it calls with the same String?
The context is that up to now I have been starting the RMI Server (only for logging at the mo, these are my first steps) explicitly in a Process. But now I want to move to "lazy" startup of the RMI registry and of the Server... so I would go LoggerInterface.log( bindingName, message ), and if the name "bindingName" is not presently in the registry it will create a new Server, and log the message using it.
More specifically, this is about me trying to automate OpenOffice apps using Java... and it occurs to me that 2 events could indeed happen almost simultaneously, so in fact even explicitly starting up the Server in each handler module might encounter "Process concurrency" problems ... so I need to have an answer to this.
I hope the answer is yes... otherwise I'm going to be a bit flummoxed about how to ensure one doesn't start up one Server Process from one calling Process, and another Server Process from another calling Process.
Thanks

I mean to use rebind() instead of the lookup()/bind() pair. It is atomic.... I understand it is atomic, but my point is that between checking whether you need to rebind (because the bound stub is invalid) and actually doing the rebind there will be an interval. If you systematically use rebind, without a prior check to make sure your Remote is actually attached to an existing Process, every call will cause a new Server Process to be created and then rebound, one after another. Which would be a mess.
I'm going to spend a bit of time looking at your two references... thanks for them.
I have thought of a possible solution involving a sort of lock, but I'm not sure if it works.
1. create a "DummyInterface" extending Remote:
public interface DummyInterface extends Remote {
}2. in the Process + Thread which actually sets up the Registry, bind a DummyInterface
Registry reg = null;
try {
reg = LocateRegistry.createRegistry( 1099 );
} catch (RemoteException e) {
return; // is this right? see below...
DummyInterface dummyStub = new DummyInterface(){};
try {
dummyStub = (DummyInterface) UnicastRemoteObject.exportObject( dummyStub, 0);
} catch (RemoteException e) {
// TODO sthg
e.printStackTrace();
try {
reg.bind( "DummyLockForLoggerServer", dummyStub );
} catch (AlreadyBoundException e) {
// every Thread in every Process (except the first such) to call "bind" will get here
return;
} catch (Exception e) {
// TODO sthg
e.printStackTrace();
}3.     the first Process + Thread which wants to set up the LoggerServer will have first to unbind the DummyLock.
try {
   reg.unbind( "DummyLockForLoggerServer" );
} catch (AccessException e) {
   // TODO sthg
   e.printStackTrace();
} catch (RemoteException e) {
   // TODO sthg
   e.printStackTrace();
} catch (NotBoundException e) {
// every Thread in every Process (except the first such) to call "unbind" will get here
return;
// only one Thread in one Process will ever succeed in getting here
// start the LoggerServer
String qualifiedClassName = ".... rmi.LoggerServer";
String[] a_commandArgs = { "java", qualifiedClassName, "logName" };
Process process = null;
try {
process = Utils.runSubprocess(a_commandArgs, null, ProcessSettings.getJavaRootDir());
} catch (IOException e) {
   // TODO sthg
   e.printStackTrace();
}... however there seem to be one or two questions about this:
- does reg = LocateRegistry.createRegistry( 1099 ); throw a RemoteException if the Registry is already bound? I don't know and intend to do a few experiments to find this out for myself. But in any event only one Process+Thread can ever bind the dummy lock
- there might be a race condition nonetheless to do with the interval between creating the Registry and binding the dummy lock... during this interval the Registry is established, and the dummylock is not yet set up... but I think this does no harm, as a Process trying to start the LoggerServer during this time will get the "NotBoundException" and simply return (and the calling thread will then sleep for a bit before trying again).

Memory leak in RMI registry ? (JRE 1.3.1_11)

Hello. I have a CLI that creates a server which calls some JNI to get
objects for a flat file database and return them. Each time I run the CLI I create a new server and bind it the RMI registry. I created a script that excecutes
the CLI in a forever loop. While this is running I notice the RMI registry program
slowly grows over time until it uses all of the system resources. I keep track of the
servers I create in a Vector and remove them once they are complete. I don't
explicitly remove them from the RMI registry because I assume they would get
garbage collected once all references to them where gone. Has anyone seen
this behavior ? Any ideas what could be happening ? Thanks.
BTW - I am running on Solaris.

The only way out of the RMI Registry is the unbind() method.
If you never unbind anything from the RMI REgistry and keep adding bindings it will grow forever.
You've got your implementation back to front. If you unbind from the Registry then allow DGC to take its course your server will eventually get an Unreferenced callback, which is the signal to remove it from local storage. Alternatively you could just unbind() and remove from local storage immediately. To be frank I am amazed that you didn't try this before posting here.

RMI Registry as a service.

I have found evidence that supports the possibility of rmiregistry.exe running as a service on windows, but I have not found any "How-To" for it. I wrote a batch file to run the command:
sc create "RMI Registry" binpath= "c:\Program Files\Java\jdk1.6.0_03\jre\bin\rmiregistry.exe" displayname= "RMI Registry" start= "auto"
However, when I attempt to start the service, I get the message:
ERROR 1053: The service did not respond to the start or control request in a timely fashion.
Where did I go wrong or is it just not possible?

Do some searching in this forum and you may find some more leads. Also: try hard to google for it.
The registry exe simply does not have the interfacing required to act as a service.
So what most people do is try to write or obtain a service wrapper that can talk to/be controlled by the service manager, and which can also run the registry exe as another process.

RMI registry inside tomcat

Hello,
I'm wondering if any of you have previous experiences in the following situation.
I have a linux server with tomcat 5.0.28 that is supposed to act as an RMI end point for clients connecting with the aforementioned RMI to do some persisting stuff. Now I figured that the easiest way is to create a servlet that creates the RMI registry and binds my server objects (so that's in the servlet's init(), with 1 load-on-startup, the servlet doesn't do anything else, at least yet).
Now problems arise: my linux server is logging "context is read-only" when trying to bind the objects to RMI. Testing on my windows laptop doesn't show the same error for some reason (although it doesn't work properly either). This is apparently normal, as the contexts are supposed to be read-only.
Thing is, I wouldn't want to run a separate rmiregistry on the server, if possible to do it with a simple servlet. But is this the easiest way?
Thank you in advance,
yours truly, in sickness and in health,
Jussi

'Context is read-only' is not a Registry error
message. You are trying to bind to something else.
Show us some code.Well, I'm not doing a lot of binding, so I'm assuming it's this part:
               DDBServer stub = (DDBServer)UnicastRemoteObject.exportObject(this, 0);
               Registry registry = LocateRegistry.getRegistry();
               registry.rebind("DDBServer", stub);The error message is:
2007-04-18 14:06:40 NamingContextListener[Catalina/localhost/DDBServer]: Creation of the naming context failed: javax.naming.NamingException: Context is read only

Some basic questions about rmi registry context "bind" and "lookup"

We have more processing to do than can be accomplished with a single computer. To solve the problem I've implemented a distributed computing solution using RMI. (The first time I saw RMI was about 2 weeks ago, so please bear with me!)
The implementation is a proof of concept not a fully fleshed out system. I have one "Workunit Distributor" computer and any number of "Data Processor" computers all on the same lan segment. "Workunit Distributor" and "Data Processor" computers are both RMI client and server to each other. The "Data Processor" computers are given the ip address and name of the "Data Distributor" on the commandline when they start. They communicate their willingness to receive and process a workunit to the ""Workunit Distributor" via a RMI call. Work units are sent to available "DataProcessors" and results are eventually returned to the "WorkunitDistributor" (minutes or hours later). The model program works quite well, and appears to be capable of doing the processing we need to get done.
But now that it seems viable, I've been asked to make it a little more scalable, flexible and self configuring. In particular, instead of one "Workunit Distributor", any number of "Workunit Distributors" should be allowed to show up or disappear from the lan at any time and the system should continue to function. I've worked out a good scheme for how this can be done, but I have a couple of questions about the RMI registry (registries?). I'm trying to keep from implementing some functionality that may already be available as a library or subsystem.
With my current model design, each computer binds to its own registry with a unique name. For instance:
CRDataProcessorImpl crdpi = new CRDataProcessorImpl(svr);
Context crDataProcessingContext = new InitialContext();
crDataProcessingContext.bind("rmi:"+hostName, crdpi);
Currently the "Data Processors" get the info they need for a Context lookup() of the one and only "Workunit Distributor" from the commandline. And the info the "Workunit Distributor" needs to do a Context lookup() of a "DataProcessor" is passed to it from each "DataProcessor" via a RMI call.
But in the newer (yet to be implemented) scheme where any and all "Workunit Distributors" show up and disappear whenever they feel like, the naming bootstrapping scheme described above won't work.
I can imagine a few ways of solving this problem. For instance, having "Workunit Distributors" multicast their contact information on the lan and have a worker thread on each "Data Processor" keep track of the naming information that was multicast. Another alternative (more organized, but more complex) might be to have a dedicated host with a "well known" address and port that "Workunit Distributors" and "Data Processors" could all go to, to register or look up at an application level. Sort of a "domain name service" for RMI. But both these schemes look like a lot of work to implement , debug and maintain.
The BEST thing would be if there was one plain vanilla RMI registry that was usable by all RMI enabled computers instead of having each computer have its own local name registry. In volume 2 of the Core Java2 book it says that every registry must be local. I'm only hoping there's been progress since the book was published and now a central rmi registry is available.
If you have any ideas about this I'd like to hear what you know.
Thanks in advance for any advice.
Lenny Wintfeld
ps - I don't believe web services, as full featured as it is, is a useful alternative. I'm moving 100's (in the future possibly 1000's) of megabytes back an forth for processing.

The local bind/rebind/unbind restriction is still there and it will always be there.
I would look at
(a) RMI/IIOP, where you use COSNaming as a registry, which doesn't have that registriction, and which also has location-independent object identifiers
(b) Jini.

RMI registry on multiple net interfaces

I'm interested in creating several RMI registry servers, each one listening in one different net interface of the same machine (two ethernet cards). Is there any way to do this without using custom RMI socket factories? From the documentation I have read, it looks like there's no possibility to choose a specific network interface. Instead, RMI registry chooses the one associated to localhost.
Thanks in advance.
Zealon

You could use
LocaeRegistry.createRegistry(port,csf,ssf) with an
RMIServerSocketFactory that binds the ServerSocket to
the appropriate network address, but you will then
discover that you can only have one Registry per JVM
because it has a fixed objectID, so don't bother.
But actually, why do you want to do this? Your stated
reason is not correct. By default any ServerSocket,
including those created by the Registry and RMI, is
bound to 'any', which means it should accept from all
network interfaces. Perhaps you have the classic
'hosts' hosts/DNS setup problem where your servers
embed 127.0.0.1 in the stub? Use
-Djava.rmi.server.hostname at the server JVM, or
better still fix your 'hosts' file or DNS setup.
EJPThanks for your reply. Maybe I didn't explain myself enough.
I'm working in medical electrocardiography, and have a PC with two net interfaces. The first one is bound to a LAN IP address that belongs to a medical network. Each one of the hosts in this medical network is an electrocardiography monitor, attached to a patient..
The second net interface is an external IP address (not LAN address).
I created a remote class called MonitorFactory, that should provide information about the electrocardiography monitors existing into the medical network. It works OK, and I cand bind MonitorFactory objects to a RMI registry with no problem at all.
There are some reasons I would like to use several RMI registries:
- First one, I need to control access from external network to my medical network. Medical patient data must be handled very carefully. I thought I could do so by enabling/disabling an RMI registry bound to the external IP address. This way, I could enable access to medical data from outside the medical network, by registering my MonitorFactory objects to this external RMI registry, but only when I decide to do that.
- Second one, I want an RMI registry always running bound to the medical LAN IP address, so I could use the applications that use MonitorFactory like a local application, not only like a remote one.
This scheme represents the system I have to build:
PC with two network interfaces
External PC <----------->|213.xxx.xxx.xxx 192.xxx.xxx.xxx|<----------> Medical network
MonitorFactory - Listens to medical data into 192.xxx.xxx.xxx network only. Bound to
external RMI registry when available and always bound to internal RMI registry.
External RMI registry - bound to 213.xxx.xxx.xxx. Enabled when I decide to do so.
Internal RMI registry - bound to 192.xxx.xxx.xxx. Always enabled.
If I create an RMI registry bound to "any" of the interfaces, I always risk my medical data to the Internet, because there is always a port open at 213.xxx.xxx.xxx accepting connections.
One possible solution could be using SSL sockets for RMI. This way, only allowed clients could connect to RMI registry. But what worries me most is the fact that a port could be open to the Internet - what about attacks to this open port? If those attacks could make RMI registry fall, medical data flow to another information systems could be interrupted, including medical alarms like critical patient status.
On the other way, I would like to maintain RMI default sockets for compatibility and future releases of my application.
Any suggestions?
Thanks in advance.
Zealon.

Cannot connect to the RMI registry.

SunMC 3.6.1 used to work fine, now get this error when running init.es_server start:
main: Successfull in setting up firewall support
Cannot connect to the RMI registry. Please check if the port myserver:2099 is in use or the interfaces are up.
Listen failed on port: 0; nested exception is:
java.io.IOException: Unable to get Any Free Port in the Range 2000-6000
Details as below
java.rmi.server.ExportException: Listen failed on port: 0; nested exception is:
java.io.IOException: Unable to get Any Free Port in the Range 2000-6000
* terminating execution *
netstat shows nothing on this port. Even tried es-config -A but same results.
Where to look for the source of this trouble?

Hi wrobbins2,
wrobbins2 wrote:
SunMC 3.6.1 used to work fine, now get this error when running init.es_server start:
main: Successfull in setting up firewall support
Cannot connect to the RMI registry. Please check if the port myserver:2099 is in use or the interfaces are up.
Listen failed on port: 0; nested exception is:
java.io.IOException: Unable to get Any Free Port in the Range 2000-6000
Details as below
java.rmi.server.ExportException: Listen failed on port: 0; nested exception is:
java.io.IOException: Unable to get Any Free Port in the Range 2000-6000
* terminating execution *
netstat shows nothing on this port. Even tried es-config -A but same results.
Where to look for the source of this trouble?Did anything change with your NIC/interface settings? Or VPN software installed? IPMP set up? I've seen things like this happen when an interface had been flagged as online... but has no IP info assigned. SunMC is going to try to grab ports on each interface... and if one doesn't have an IP assigned it will fail.
Regards,
[email protected]

RMI registry weirdness, API versioning, and more

Hi folks,
     I have some RMI questions. I'd like to start by giving background on the software and our intentions with RMI.
     Our software is a molecular biology analysis and simulation tool. Since the technology is very proprietary, we've used RMI to split the Java software into a front-end GUI client that that's distributed to users and a back-end server that makes use of our in-house C++ tools.
     At the moment our user base is small, mostly a handful of academic researchers, but even with these few releases are getting difficult to manage. The problem, of course, is that when the server back-end is upgraded, if any serializable or remotable APIs are changed, the user must also upgrade their client. Our users have made it clear that this is an unacceptable inconvenience, and since we frequently push new feature-filled releases, its difficult to keep the APIs stable. Additionally, 40% of the original code base is absolute tripe, the inflexible, ill-thought, and monolithic work of a contractor who was at at deadline and had to 'just get the job done'. With only two developers (one of them part-time), we are forced to rewrite portions of this old code in small spurts as most of our time is taken up either adding features or working on the C++ tools. In short, there's simply no way we can stabilize our APIs at this time.
     My first (perhaps naive) solution was simple: the client/server pair are built with a common API version number that is incremented each time the API of a serializable or remotable API must be changed for a new release. This version number is appended to the RMI URI for the server. For example, when using API version 13, if the back-end service is told to listen on the following URI:
     //remote.mycompany.com/myobject
...the back-end would implicitly bind to...
     //remote.mycompany.com/myobject-13
     Since the client and server are built with the same API version, the client knows to append -13 to whatever URI the user specifies to connect to a back-end with a compatible API. This lets the user think they're connecting to the 'usual' URI, but allows us to run servers with varying APIs concurrently on the same physical machine, thus our users can upgrade at their leisure and we can push new releases whenever we please.
     I prefer this solution because its very non-intrusive code-wise and allows us developers complete freedom, but it seems prone to subtle problems. We have three releases (hence three servers) and clients are able to function initially, but eventually they start reporting not-bound and class UID/checksum errors - exactly what this system is supposed to prevent. The three services appear to work when started initially but fail sporadically after some period of time. It seems to me that the RMI registry is getting confused when deciding which classes from which service should be sent to which client.
     I should note that rmiregistry requires us to pass in the path to our classes to its JVM (with -J) or it throws NoClassDefFoundError errors when a client connects to the back-end service (if memory serves, our logger is the offending class, so perhaps the registry is executing a static initializer that prints log messages or something). We only pass in the path to one set of classes right now (the oldest of our API revisions). I'm not sure if passing all three would help, but I don't see how it would, and I really don't have the time to experiment. Interestingly, this class path requirement only started happening a few weeks ago - previously rmiregistry didn't seem to care where our logging classes were. I'm not sure if this is contributing to the concurrency problem stated above, but if there's reasonable suspicion I'm more than happy to figure out why this is happening. Also, I remember reading on some web site that setting the rmiregistry class path with -J could cause other strange problems relating to RMI stubs, so could this be a likely suspect? I wish I was more familiar with the guts of RMI as to know what's going on in the registry. Should I be seeing such problems when binding multiple versions of the same class instance?
     I suppose I'd really like, aside from the informed opinions and suggestions of experienced Java programmers, is an architectural overview of the RMI implementation so I can answer these questions myself, but I haven't found anything in that vein. Ideally I'd like to look at the code for the RMI implementation. Is this possible? I'm not 'hip' to Sun's code sharing policies, what portions of their code base they open up if any. Can anyone offer any hints?
     We did come up with some other possible solutions for the API versioning problem. Dynamic class loading via HTTP in particular is my next best hope. Tentatively speaking, it seems that this would help minimize API breakage so long as modifications are limited to adding elements to the API and not removing them. It seems to me that allowing users to download classes at runtime would allow us developers more flexibility, even though users would be forced to upgrade every once in a while, albeit less frequently than they otherwise would.
     Also considered was a separate tool for automated management of the client software, i.e., an auto-update utility. I'd rather not go down this path; I think it would annoy our users, and our two-man development team is busy enough without worrying about more cruft.
     Any additional suggestions are welcome, as is any insight into the Sun's RMI implementation. Advice, links to documentation, "hey stupid, google for <somthing obvious>" would be appreciated.
Cheers :-)
-Nick

or you could buy mine (http://www.rmiproxy.com/javarmi), but I'll give you three tips:
(1) If possible don't change existing interfaces, just extend them, i.e. version them by extending them:
public interface MyRemoteVersion1 extends Remote {}
public inteface MyRemoteVersion2 extends MyRemoteVersion1 {}This way old clients can still use the old services even if they receive a newer stub.
(2) Do the same with the implementations, and load & register both, with different names as ou are doing. Don't use the same class name for a new version otherwise you will confuse the class loader. Altneratively you could use different class loaders for teh different versions to keep them separate, but that's a large can of worms.
(3) Ignore your feelings about the code base. It's installed out there and it's a product now, you just have to live with it unless you can instaneously upgrade all your clients, which you can't. You will probably always have a client running the original version for reasons entirely beyond your control.
(4) Do use the codebase feature if you possibly can. Don't install anything at a client that it could get via a codebase, e.g. stubs. The only thing that clients should need is the remote interfaces and the the true client code.
(5) Make sure every version of every marshalled class has the same setversionuid and make sure that this is there from the beginning. Make sure you only evolve these classes in ways which will be compatible under serialization - see the spec.
Good luck
EJP

Recommended Windows multipatform ports for RMI registry....

Hi,
Can anyone recommend suitable RMI registry ports that will work across different windows platforms (NT/2000/XP) as I have two RMI servers running on a host machine.
Presently I have one RMI server object bound to a registry on port 1099 and the other on port 2001. My RMI client correctly connects on Windows 2000 for both of these however Windows XP doesn't work for port 1099. Also port 2001 does not work over the internet and yes I have configured the firewall correctly!
Any recommendations for using correct ports please?
Regards,
Oneal

1. Why do you need two registries?
2. There is some amount of chaos in port numbers; 1099 is a "registered" port, where exclusive use is not guaranteed.
o You can google for "well known port" and you will easily find a list of registered ports; you could pick one from someone you think is out of business or where the use is patently clear to be obsolete.
o You could choose an arbitrary port number in the dynamically-assigned range,.
Here's an excerpt from a document I found:
The port numbers are divided into three ranges: the Well Known Ports,
the Registered Ports, and the Dynamic and/or Private Ports.
The Well Known Ports are those from 0 through 1023.
The Registered Ports are those from 1024 through 49151
The Dynamic and/or Private Ports are those from 49152 through 65535

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