Singletons across multiple JVMs

I have an EJB application container which is spread across multiple JVMs(something like a clustered EJB container). I am using a Singleton class to hand out 'running serial numbers'. Therefore there is a Singleton class per JVM(which is not very clean but i chose this path in the absence of anything better). Each singleton comes up when it is first invoked within a JVM and reads a starting running number and a pool of numbers from the database. This way multiple Singletons will not step on each other when doling out the serial numbers and there is no need to go back to the database for every request to the 'running serial number'.
Is there some way to do some of the initialization within these Singleton's just ONCE across the multiple instances of the JVM ie. a real Singleton across multiple JVMs?
Thanks
Ramdas

Pranav,
thanks for your suggestions.
the idea of using a Session bean to access a serialized object was one of my design options when i first implemented this, but then i decided against it because of the overhead of having to make an RMI call for every request to the 'running serial number'. The application being written is for a performance benchmark, and the request to the number being done at least once for every transaction, I chose to use Singletons.
It is a clustered EJB container(not like most conatiners), in the sense that a single container is spread across multiple JVMs.
Now if your application is getting clustured
then you have a problem, in that what you can do is
what object you have made put it in JNDI context and
everytime you want to edit it pull it out edit and set
it back. This will act a your singleton object in
clustured environment accross JVM'sI did not fully understand the second part of your solution????
Ramdas

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Sharing an iTunes Music Library across multiple user accounts.
Hello Everybody!
Firstly, this was designed to be run in Mac OS X 10.4 Tiger. It will not work with earlier versions of Mac OS X! Sorry.
Here's a handy tip for keeping your hard drive neat and tidy, it also saves space, what in effect will be done is an iTunes music library will be shared amongst multiple users on the same machine. There are advantages and disadvantages to using this method.
• Firstly I think it might be worthwhile to state the advantages and disadvantages to using this approach.
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This is a hearty process to undertake, so only follow this tutorial if you're willing to go all the way to the end of it.
Process:
Step 1:
Firstly, we need to organize the host library, I tidied mine up, removing excess playlists, random files, things like that. this will make thing a bit easier in the later stages of this process.
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Overview:
So far we have done the following steps:
1. Organized the host library.
2. Placed the iTunes directory into a 'public' directory so that other users may use it. (this step is essential if you plan on sharing the library across multiple accounts on the same machine. NOTE: this step is only necessary if you are wanting to share you library across multiple accounts on the same machine, if you simply want to share the music across a network, use the iTunes sharing facility.
3. set ownership and permissions for the iTunes music folder.
Step 2:
Currently the administrator is the only user who can use this library, however we will address this soon. In this step we will enable iTunes music sharing in the administrator's account, this will enable other users to access the files in the library.
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Sharing only selected content may be useful if their is explicit content in the library and minors use the network or machine that the library is connected to.
If you have selected "share entire library" go to Step 3, if you have selected share "share selected playlists" read on.
After clicking "share selected playlists" you must then select the playlists that you intend to share across your accounts and network. Once you have finished selecting the playlists, click "OK" to save the settings.
Overview:
In this step we:
1. Enabled iTunes sharing in the administrator's account, now, users on the local network may access the iTunes library, however, users on the same machine may not.
Step 3:
Now we will enable users on the same machine to access the library on the machine. This is achieved by logging in as each user, opening iTunes, opening iTunes preferences, and clicking "look for shared music". now all users on the machine may also access the library that the administrator controls.
This in effect will mean that the user will not need to use their user library, it will be provided to them via a pseudo network connection.
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This is done through the use of an Automator Application: this application does the following actions.
1. Uses the "Finder" action "Get Specified Finder Items"
1a. The user's "~/Music/iTunes/iTunes Music" folder
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3. Uses the "Finder" action "Move to Trash"
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4a. with the following:
on run {input, parameters}
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Overview:
Here we:
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2. (Optional) I have created a login application that will remove any content that has been added to user iTunes libraries, this in effect stops other users of the machine from adding music and files to iTunes.
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Summary:
We have shared a single iTunes library across multiple user account, while still allowing for network sharing. This method is designed to save space on machines, particularly those with smaller hard drives.
I hope that this hint proves to be helpful and I hope everybody will give me feedback on my process.
regards,
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how to share music between different accounts on a single computer

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