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| | | Singleton in clustered environment | Singleton in clustered environment 2004-12-02 - By SOURABH Srivastava
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Varun,
There are some products available which manages cache data in a single JVM. All
other JVM's can access data from that single jvm.
Thanks,
Sourabh
-- --Original Message-- --
From: An interest list for Sun Java Center J2EE Pattern Catalog [mailto
:J2EEPATTERNS-INTEREST@(protected)]On Behalf Of ashraf galal
Sent: Thursday, December 02, 2004 3:13 PM
To: J2EEPATTERNS-INTEREST@(protected)
Subject: Re: Singleton in clustered environment
you can implement this functionality using the database i n one JVM and direct
the others to read it from there or replicate this database table to the other
JVMs too.
Ashraf Galal
(416)804-8359
>From: "Varun Rally, Noida" <varunr@(protected)> >Reply-To: An interest
list for Sun Java Center J2EE Pattern Catalog <J2EEPATTERNS-INTEREST@(protected)
.COM> >To: J2EEPATTERNS-INTEREST@(protected) >Subject: Re: Singleton in
clustered environment >Date: Thu, 2 Dec 2004 14:39:58 +0530 > >My requirement
is that I need only one single instance for the whole >application in clustered
environment. > >i.e. even if there are more than one JVMs , all of them should
access single >instance. > > > >Exact requirement is that we have a class that
handles the locking >functionality of documents in our > >Application. We
create only one singleton object of this class and this >object maintains a map
of locked documents. > > > >Now, in clustered environment, there will be more
than one JVMs and hence >more than one objects that are handling > >The locking
information, which is actually wrong. > > > >I hope I am clear in my words. >
>Waiting for your reply. > >Thanks and regards > > > >Varun Rally > > > > > > >
> __ __ > >From: An interest list for Sun Java Center J2EE Pattern Catalog >
[mailto:J2EEPATTERNS-INTEREST@(protected)] On Behalf Of Tubman Aharon >Sent:
Thursday, December 02, 2004 1:52 PM >To: J2EEPATTERNS-INTEREST@(protected)
>Subject: Re: Singleton in clustered environment > > > >I agree with Mall. It is
bad practice to access singleton remotely. Can you >describe the meter of you
problem? Which kind of service it provides? > > > > __ __ > >From: An interest
list for Sun Java Center J2EE Pattern Catalog >[mailto:J2EEPATTERNS-INTEREST
@(protected)] On Behalf Of Mall, Vishnu >(Cognizant) >Sent: Thursday, December
02, 2004 8:08 AM >To: J2EEPATTERNS-INTEREST@(protected) >Subject: Re:
Singleton in clustered environment > > > >Hi Varun, > > > >The Concept of
Singleton is "one and only one instance of a class at any >given point of time
in a single JVM". The moment you mention a clustered >environment, you would
end up having multiple JVMs and hence each JVM would >have an instance of this
Singleton class. Hope this helps. Do let me know >your exact requirement in
detail. > > > >Thanks and Regards, >Vishnu Mall >Cognizant Technology Solutions
, >Technocomplex, Kolkata >Ph : 2357 3211/12/13 Extn : 3253 >email : MVishnu@(protected)
.cognizant.com > >-- --Original Message-- -- >From: Varun Rally, Noida [mailto
:varunr@(protected)] >Sent: Thursday, December 02, 2004 11:03 AM >To:
J2EEPATTERNS-INTEREST@(protected) >Subject: Singleton in clustered environment
> >Hi all, > > > >I have to implement singleton in clustered environment. >
>Can somebody, help with some online resource/link or pattern for doing the
>same. > > > >Regards, > >Varun Rally > > > >===================================
================================= >Companion Site: http://www.corej2eepatterns
.com J2EE BluePrints: >http://java.sun.com/blueprints/corej2eepatterns List
Archive: >http://archives.java.sun.com/archives/j2eepatterns-interest.html
>Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to >listserv@(protected)
> > > >???????? ?? ????? ??????? ???? ???????? ??? ?????? ?????? ???? ???? ?????
? >???? ??? ????? ?????? ?/?? ?????? ????? ?/?? ?????? ?????? ?/?? ??? ???? ???
>???? ????? ????? ?????? ?????? ????? > >Correspondence with Leumi by electronic
mail is for general purposes only >and may not be relied upon for the purpose
of effecting any activities >and/or transactions whatsoever and/or as a
substitute for advice and/or in >any other manner and is subject to the
conditions of use which have been >provided to the Customer > > > > > >This e
-mail and any files transmitted with it are for the sole use of the >intended
recipient(s) and may contain confidential and privileged >information. >If you
are not the intended recipient, please contact the sender by reply >e-mail and
destroy all copies of the original message. >Any unauthorised review, use,
disclosure, dissemination, forwarding, >printing or copying of this email or
any action taken in reliance on this >e-mail is strictly >prohibited and may be
unlawful. > >Visit us at http://www.cognizant.com > >==========================
========================================== >Companion Site: http://www
.corej2eepatterns.com J2EE BluePrints: >http://java.sun.com/blueprints
/corej2eepatterns List Archive: >http://archives.java.sun.com/archives
/j2eepatterns-interest.html >Unsubscribing: email "signoff J2EEPATTERNS-INTEREST
" to >listserv@(protected) >===================================================
================= >Companion Site: http://www.corej2eepatterns.com J2EE
BluePrints: >http://java.sun.com/blueprints/corej2eepatterns List Archive:
>http://archives.java.sun.com/archives/j2eepatterns-interest.html >Unsubscribing
: email "signoff J2EEPATTERNS-INTEREST" to >listserv@(protected) > >===========
========================================================= >Companion Site: http:
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/j2eepatterns-interest.html >Unsubscribing: email "signoff J2EEPATTERNS-INTEREST
" to listserv@(protected)
==================================================================== Companion
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/j2eepatterns-interest.html Unsubscribing: email "signoff J2EEPATTERNS-INTEREST"
to listserv@(protected)
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=iso-8859 (See http://iso-8859.ora-code.com)-1">
<META content="MSHTML 6.00.2800.1476" name=GENERATOR></HEAD>
<BODY>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080
size=2>Varun,</FONT></SPAN></DIV>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080 size=2>There
are some products available which manages cache data in a single JVM. All other
JVM's can access data from that single jvm.</FONT></SPAN></DIV>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080
size=2></FONT></SPAN> </DIV>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080
size=2>Thanks,</FONT></SPAN></DIV>
<DIV><SPAN class=402004709-02122004><FONT face=Arial color=#000080
size=2>Sourabh</FONT></SPAN></DIV>
<BLOCKQUOTE>
<DIV class=OutlookMessageHeader dir=ltr align=left><FONT face=Tahoma
size=2>-- --Original Message-- --<BR><B>From:</B> An interest list for Sun
Java Center J2EE Pattern Catalog
[mailto:J2EEPATTERNS-INTEREST@(protected)]<B>On Behalf Of </B>ashraf
galal<BR><B>Sent:</B> Thursday, December 02, 2004 3:13 PM<BR><B>To:</B>
J2EEPATTERNS-INTEREST@(protected)<BR><B>Subject:</B> Re: Singleton in
clustered environment<BR><BR></FONT></DIV>
<DIV>
<P>you can implement this functionality using the database i n one JVM and
direct the others to read it from there or replicate this database table to
the other JVMs too.<BR><BR></P><BR><BR><BR>
<DIV>Ashraf Galal <BR>(416)804-8359</DIV>>From: "Varun Rally, Noida"
<varunr@(protected)> >Reply-To: An interest list for Sun Java
Center J2EE Pattern Catalog <J2EEPATTERNS-INTEREST@(protected)> >To
:
J2EEPATTERNS-INTEREST@(protected) >Subject: Re: Singleton in clustered
environment >Date: Thu, 2 Dec 2004 14:39:58 +0530 > >My requirement
is that I need only one single instance for the whole >application in
clustered environment. > >i.e. even if there are more than one JVMs ,
all of them should access single >instance. > > > >Exact
requirement is that we have a class that handles the locking >
;functionality
of documents in our > >Application. We create only one singleton object
of this class and this >object maintains a map of locked documents. >
> > >Now, in clustered environment, there will be more than one JVMs
and hence >more than one objects that are handling > >The locking
information, which is actually wrong. > > > >I hope I am clear in
my words. > >Waiting for your reply. > >Thanks and regards >
> > >Varun Rally > > > > > > > > __ __ >
>From: An interest list for Sun Java Center J2EE Pattern Catalog
>[mailto:J2EEPATTERNS-INTEREST@(protected)] On Behalf Of Tubman Aharon
>Sent: Thursday, December 02, 2004 1:52 PM >To:
J2EEPATTERNS-INTEREST@(protected) >Subject: Re: Singleton in clustered
environment > > > >I agree with Mall. It is bad practice to
access
singleton remotely. Can you >describe the meter of you problem? Which kind
of service it provides? > > > > __ __ > >From: An interest
list for Sun Java Center J2EE Pattern Catalog
>[mailto:J2EEPATTERNS-INTEREST@(protected)] On Behalf Of Mall, Vishnu
>(Cognizant) >Sent: Thursday, December 02, 2004 8:08 AM >To:
J2EEPATTERNS-INTEREST@(protected) >Subject: Re: Singleton in clustered
environment > > > >Hi Varun, > > > >The Concept of
Singleton is "one and only one instance of a class at any >given point of
time in a single JVM". The moment you mention a clustered >environment,
you
would end up having multiple JVMs and hence each JVM would >have an
instance of this Singleton class. Hope this helps. Do let me know >your
exact requirement in detail. > > > >Thanks and Regards, >
;Vishnu
Mall >Cognizant Technology Solutions, >Technocomplex, Kolkata >Ph :
2357 3211/12/13 Extn : 3253 >email : MVishnu@(protected) >
>-- --Original Message-- -- >From: Varun Rally, Noida
[mailto:varunr@(protected)] >Sent: Thursday, December 02, 2004 11:03
AM >To: J2EEPATTERNS-INTEREST@(protected) >Subject: Singleton in
clustered environment > >Hi all, > > > >I have to implement
singleton in clustered environment. > >Can somebody, help with some
online resource/link or pattern for doing the >same. > > >
>Regards, > >Varun Rally > > >
>====================================================================
>Companion Site: http://www.corej2eepatterns.com J2EE BluePrints:
>http://java.sun.com/blueprints/corej2eepatterns List Archive:
>http://archives.java.sun.com/archives/j2eepatterns-interest.html
>Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to
>listserv@(protected) > > > >???????? ?? ????? ??????? ????
???????? ??? ?????? ?????? ???? ???? ?????? >???? ??? ????? ?????? ?/??
?????? ????? ?/?? ?????? ?????? ?/?? ??? ???? ??? >???? ????? ????? ??????
?????? ????? > >Correspondence with Leumi by electronic mail is for
general purposes only >and may not be relied upon for the purpose of
effecting any activities >and/or transactions whatsoever and/or as a
substitute for advice and/or in >any other manner and is subject to the
conditions of use which have been >provided to the Customer > > >
> > >This e-mail and any files transmitted with it are for the sole
use of the >intended recipient(s) and may contain confidential and
privileged >information. >If you are not the intended recipient, please
contact the sender by reply >e-mail and destroy all copies of the original
message. >Any unauthorised review, use, disclosure, dissemination,
forwarding, >printing or copying of this email or any action taken in
reliance on this >e-mail is strictly >prohibited and may be unlawful.
> >Visit us at http://www.cognizant.com >
>====================================================================
>Companion Site: http://www.corej2eepatterns.com J2EE BluePrints:
>http://java.sun.com/blueprints/corej2eepatterns List Archive:
>http://archives.java.sun.com/archives/j2eepatterns-interest.html
>Unsubscribing: email "signoff J2EEPATTERNS-INTEREST" to
>listserv@(protected)
>====================================================================
>Companion Site: http://www.corej2eepatterns.com J2EE BluePrints:
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>http://archives.java.sun.com/archives/j2eepatterns-interest.html
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>listserv@(protected) >
>====================================================================
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http://archives.java.sun.com/archives/j2eepatterns-interest.html
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</DIV>====================================================================
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for the individual or entity to which it is addressed. It may contain
privileged, confidential information which is exempt from disclosure under
applicable laws. If you are not the intended recipient, please note that you
are strictly prohibited from disseminating or distributing this information
(other than to the intended recipient) or copying this information. If you have
received this communication in error, please notify us immediately by return
email.<br></BODY></HTML>
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