You are viewing a plain text version of this content. The canonical link for it is here.
Posted to user@hivemind.apache.org by Guy Hacham <gu...@gmail.com> on 2005/03/30 15:36:18 UTC
Does Hivemind can support 2 (or more) versions of the same service?
Hi,
I'm a newbie to hivemind and currently I'm reviewing the feature set looking
for a way to load 2 different versions of the same service into hivemind.
My requirement here is to be able to load 2 or more versions of a service into
the JVM so they can live together with peace.
A use case for this requirements is as follows:
Service A was deployed with v4.0 of the system.
The system is upgraded to v4.1 but the server should support both versions in
parallel, i.e. both v4.0 and v4.1.
Service A was changed in v4.1, (and to make it more complicated) including its
services (methods) and its dependencies.
Service B was also changed but Service C was left the same.
To support both version we need 2 versions of Service A, 2 versions of Service
B and only one version of Service C.
Is there a way to support this scenario in Hivemind?
I saw that there is a version attribute on the service element but I don't
seem to find any other reference to it and how hivemind handles it.
Your help is appreciated.
Thanks,
Guy.
---------------------------------------------------------------------
To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
Re: Does Hivemind can support 2 (or more) versions of the same service?
Posted by Howard Lewis Ship <hl...@gmail.com>.
Believe it or not, part of HiveMind's goals is to be *simple*. Some
systems, like OSGi and Jini, and even somewhat Spring, have the
ability to re-deploy a service (or service implementation) and
transition existing clients over to the new code.
HiveMind doesn't do this; it is designed to be J2EE friendly, with the
intention that you redeploy your updated app and existing clients need
to re-connect.
Further, the way HiveMind works allows for some very involved
relationships between services and modules. The overhead that would
be necessary to track this properly (especially the contributions
aspect) would be prohibitive, if it was even possible.
In you sitution, would is be reasonable to deploy a new EAR (that
incorporates a version number) and leverage J2EE for connecting
clients to the new or old code?
On Wed, 30 Mar 2005 16:22:24 +0200, Guy Hacham <gu...@gmail.com> wrote:
> The services cannot be shutdown as they need to service clients from
> previous versions, i.e. v4.0. yes, the services are called remotely by
> a client application, but there are also other services that are
> running locally on the server doing some background processing.
>
> The scenario for justifying this situation is when you have 2 versions
> of the same system running on 1 server that needs to serve clients and
> other background processes of these two versions.
>
> There are way to deal with it by changing package names or class names
> to reflect the version they are developed for, i.e.
> com.acme.40.SomeClass nad com.acme.41.SomeClass but I find this
> technique cumbersome.
> A nicer solution is to be able to develop com.acme.SomeClass and use
> the SCM for maintaining versions. On the deployment descriptor, in
> this case, hivemodule.xml you will be able to denote the version of
> the service and in its dependencies you can either use a default
> version, the same as the module, or a specific one.
>
> This way you can deploy 2 versions of the same service and use them
> concurrently to serve clients from different versions.
>
> Guy.
>
>
> On Wed, 30 Mar 2005 15:54:52 +0200, Achim Huegen <ah...@gmx-topmail.de> wrote:
> > What dependencies keep you from shutting down the old version of Service
> > A? Is Service C a user of Service A or
> > are your services called remotely (rmi, webservices etc.) ?
> >
> > Achim
> >
> >
> > Guy Hacham wrote:
> > > Hi,
> > >
> > > I'm a newbie to hivemind and currently I'm reviewing the feature set looking
> > > for a way to load 2 different versions of the same service into hivemind.
> > >
> > > My requirement here is to be able to load 2 or more versions of a service into
> > > the JVM so they can live together with peace.
> > >
> > > A use case for this requirements is as follows:
> > > Service A was deployed with v4.0 of the system.
> > > The system is upgraded to v4.1 but the server should support both versions in
> > > parallel, i.e. both v4.0 and v4.1.
> > > Service A was changed in v4.1, (and to make it more complicated) including its
> > > services (methods) and its dependencies.
> > > Service B was also changed but Service C was left the same.
> > > To support both version we need 2 versions of Service A, 2 versions of Service
> > > B and only one version of Service C.
> > >
> > > Is there a way to support this scenario in Hivemind?
> > >
> > > I saw that there is a version attribute on the service element but I don't
> > > seem to find any other reference to it and how hivemind handles it.
> > >
> > > Your help is appreciated.
> > >
> > > Thanks,
> > > Guy.
> > >
> > > ---------------------------------------------------------------------
> > > To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> > > For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
> > >
> > >
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
> >
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
>
>
--
Howard M. Lewis Ship
Independent J2EE / Open-Source Java Consultant
Creator, Jakarta Tapestry
Creator, Jakarta HiveMind
Professional Tapestry training, mentoring, support
and project work. http://howardlewisship.com
---------------------------------------------------------------------
To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
Re: Does Hivemind can support 2 (or more) versions of the same service?
Posted by Guy Hacham <gu...@gmail.com>.
The services cannot be shutdown as they need to service clients from
previous versions, i.e. v4.0. yes, the services are called remotely by
a client application, but there are also other services that are
running locally on the server doing some background processing.
The scenario for justifying this situation is when you have 2 versions
of the same system running on 1 server that needs to serve clients and
other background processes of these two versions.
There are way to deal with it by changing package names or class names
to reflect the version they are developed for, i.e.
com.acme.40.SomeClass nad com.acme.41.SomeClass but I find this
technique cumbersome.
A nicer solution is to be able to develop com.acme.SomeClass and use
the SCM for maintaining versions. On the deployment descriptor, in
this case, hivemodule.xml you will be able to denote the version of
the service and in its dependencies you can either use a default
version, the same as the module, or a specific one.
This way you can deploy 2 versions of the same service and use them
concurrently to serve clients from different versions.
Guy.
On Wed, 30 Mar 2005 15:54:52 +0200, Achim Huegen <ah...@gmx-topmail.de> wrote:
> What dependencies keep you from shutting down the old version of Service
> A? Is Service C a user of Service A or
> are your services called remotely (rmi, webservices etc.) ?
>
> Achim
>
>
> Guy Hacham wrote:
> > Hi,
> >
> > I'm a newbie to hivemind and currently I'm reviewing the feature set looking
> > for a way to load 2 different versions of the same service into hivemind.
> >
> > My requirement here is to be able to load 2 or more versions of a service into
> > the JVM so they can live together with peace.
> >
> > A use case for this requirements is as follows:
> > Service A was deployed with v4.0 of the system.
> > The system is upgraded to v4.1 but the server should support both versions in
> > parallel, i.e. both v4.0 and v4.1.
> > Service A was changed in v4.1, (and to make it more complicated) including its
> > services (methods) and its dependencies.
> > Service B was also changed but Service C was left the same.
> > To support both version we need 2 versions of Service A, 2 versions of Service
> > B and only one version of Service C.
> >
> > Is there a way to support this scenario in Hivemind?
> >
> > I saw that there is a version attribute on the service element but I don't
> > seem to find any other reference to it and how hivemind handles it.
> >
> > Your help is appreciated.
> >
> > Thanks,
> > Guy.
> >
> > ---------------------------------------------------------------------
> > To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> > For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
> >
> >
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
Re: Does Hivemind can support 2 (or more) versions of the same service?
Posted by Achim Huegen <ah...@gmx-topmail.de>.
What dependencies keep you from shutting down the old version of Service
A? Is Service C a user of Service A or
are your services called remotely (rmi, webservices etc.) ?
Achim
Guy Hacham wrote:
> Hi,
>
> I'm a newbie to hivemind and currently I'm reviewing the feature set looking
> for a way to load 2 different versions of the same service into hivemind.
>
> My requirement here is to be able to load 2 or more versions of a service into
> the JVM so they can live together with peace.
>
> A use case for this requirements is as follows:
> Service A was deployed with v4.0 of the system.
> The system is upgraded to v4.1 but the server should support both versions in
> parallel, i.e. both v4.0 and v4.1.
> Service A was changed in v4.1, (and to make it more complicated) including its
> services (methods) and its dependencies.
> Service B was also changed but Service C was left the same.
> To support both version we need 2 versions of Service A, 2 versions of Service
> B and only one version of Service C.
>
> Is there a way to support this scenario in Hivemind?
>
> I saw that there is a version attribute on the service element but I don't
> seem to find any other reference to it and how hivemind handles it.
>
> Your help is appreciated.
>
> Thanks,
> Guy.
>
> ---------------------------------------------------------------------
> To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
> For additional commands, e-mail: hivemind-user-help@jakarta.apache.org
>
>
---------------------------------------------------------------------
To unsubscribe, e-mail: hivemind-user-unsubscribe@jakarta.apache.org
For additional commands, e-mail: hivemind-user-help@jakarta.apache.org