Hi Martin,
In a Service Group, we do not have runtime data, as aliases and other
relevant subscription data are provided in the application deployment.
If you need to start two instances of the same cartridge type, what you can
do is to put them in the application itself without using a group, and then
specify the startup order using cartridge aliases:
"startupOrders": [
"cartridge.*<alias1>*, cartridge.*<alias2>*, cartridge.
*<alias3>*"
],
all the aliases refer to the same cartridge type.
On Thu, Nov 20, 2014 at 9:35 AM, Martin Eppel (meppel) <[email protected]>
wrote:
> Hi Udara,
>
>
>
> Yes, I confirmed, there are real use cases where we have dependencies on
> the same cartridge type but different subscriptions, one is an example of
> active / standby scenario another one a scenario to patch / upgrade the
> system.
>
>
>
> Quoting the response below:
>
>
>
>
>
> ns-01 and ns-02 are instances of a network server cluster. Strictly
> speaking they belong to the same cluster so having both be the same
> cartridge type makes sense. Making them different cartridge types seems
> wrong. We really only need either ns-01 or ns-02 to be up in order to
> declare the cluster as available and I can't see how we do that if we use
> different cartridge types.
>
> One of the original use cases was to use grouping to represent a cluster.
> One use cases might involve have multiple subscriptions representing
> collectively a cluster, so each having the same cartridge type would be
> useful. Each subscription in this case would have one or more instances.
> For example, if we want to represent a cluster with a subscription a. At
> some point later, we might want to add a subscription b to the group which
> point to a different version of code (likely a patched version) and remove
> subscription a after we've deploy and verified subscription b. I imagine
> doing this by revising a group with additional subscriptions with the same
> cartridge type.
>
> I believe Matt has a similar requirement where one VM is in active state
> and the other is in standby.
>
>
>
>
>
>
>
> *From:* Martin Eppel (meppel)
> *Sent:* Wednesday, November 19, 2014 6:21 PM
> *To:* [email protected]
> *Subject:* RE: [grouping][question] cartrdige type in dependency
> definition
>
>
>
> Hi Udara,
>
>
>
> No problem, I was just wondering if it is supported or not.
>
>
>
> On the other hand we might have a real use case, let me follow up on this
>
>
>
> Thanks
>
>
>
> Martin
>
>
>
> *From:* Udara Liyanage [mailto:[email protected] <[email protected]>]
> *Sent:* Wednesday, November 19, 2014 6:16 PM
> *To:* dev
> *Subject:* Re: [grouping][question] cartrdige type in dependency
> definition
>
>
>
> Hi Martin,
>
> Creating another cartridge type is just changing the type parameter of the
> existing cartridge json if you are using the base image approach and
> deploying the new json.
>
> If the requirement is only the easiness in testing, I don't think
> implementing this feasibility is necessary given that we are in a tight
> schedule. However if there is a real world use case I am OK.
>
> Touched, not typed. Erroneous words are a feature, not a typo.
>
> --
> Thanks and Regards,
>
> Isuru H.
> +94 716 358 048* <http://wso2.com/>*
>
>
> * <http://wso2.com/>*
>
>
>
