[jboss-as7-dev] Multiple HQ servers on the same AS instance

[Brian Stansberry]

On 9/1/11 10:08 AM, Brian Stansberry wrote:
> On 9/1/11 9:45 AM, Andy Taylor wrote:
>> On 09/01/2011 03:23 PM, Brian Stansberry wrote:
>>> Just an FYI for those interested in the HornetQ integration into the
>>> AS. I recalled this morning a call I was on a couple years back where
>>> an HA architecture was discussed based on two or more AS's w/ 2 HQ
>>> servers on each, one on each AS acting as backup to one on another.
>>> From chatting with Clebert today, it seems that architecture was
>>> implemented.
>> We have also discussed adding functionality to allow a single hornetq
>> instance to cope with multiple journals, meaning a server could also be
>> a backup as well as a live. If we did this you would only ever need a
>> single instance. Depending on time frames this could be a better
>> solution although we didnt have any plans to do it right away.
>
> The time frame is within three months, as in 7.1 we need to preserve any
> critical HQ functionality that exists in EAP 5.1.
>

QE has raised this issue as a blocker and is concerned that not having 
the features prohibits their ability to develop test infrastructure for 
it, which is part of their overall test plan.

I've opened https://issues.jboss.org/browse/AS7-1772 for this.

The console and JON teams need a nailed down messaging subsystem 
management API, and the possibility of multiple HQ servers affects that, 
so we need to decide ASAP if that's what we're going to do.

More below...

>>>
>>> This has implications for the HQ integration in AS 7.1. Two support
>>> this kind of architecture, we'd need to:
>>>
>>> 1) Add a high level element in the jboss-as-messaging.xsd schema that
>>> encapsulates all the existing element and represents an HQ server.
>>>
>>> 2) Add a level to the messaging subsystem management resource tree for
>>> same.
>>>

Since the console/JON team really need a finalized API, I spent some 
time today working up a patch that would do this part.[1]  If we end up 
not going with multiple servers, oh well. If we do, we can push this in 
and it will give the console the correct API.

This add a hornetq-server=default level to the messaging subsystem tree. 
The subsystem=messaging resource has no attributes, and only one type of 
child: "hornetq-server". All attributes and children that were under 
subsystem=messaging are now under 
subsystem=messaging/hornetq-server=default.

This patch is only a piece of the picture; the other 3 items in this 
list would need to be done.

[1] https://github.com/bstansberry/jboss-as/tree/AS7-1772

>>> 3) Rework any HQ-related MSC service names to account for the
>>> possibility of multiple HQ servers.
>>>
>>> 4) Figure out an other issues this introduces as far as integrating
>>> with other services that depend on the messaging services.
>>>
>>
>
>


-- 
Brian Stansberry
Principal Software Engineer
JBoss by Red Hat