[jboss-as7-dev] Graceful Shutdown

[Jason Greene]

FYI this task is open for the taking if anyone wants it!

Sent from my iPhone

On Sep 16, 2011, at 9:28 AM, "David M. Lloyd" <david.lloyd at redhat.com> wrote:

> The idea is that existing permit holders (which includes already-running 
> requests, already-open transactions, etc.) can still get new permits, 
> but those who do not already have a transaction running or open sessions 
> or whatever cannot and should be redirected to another node.
> 
> On 09/16/2011 09:12 AM, Scott Marlow wrote:
>> Is this a fail-fast design? Or should all currently running user
>> requests succeed? If new transactions cannot be started, I would think
>> that means some running user requests will fail.
>> 
>> 
>> On 09/13/2011 10:31 AM, David M. Lloyd wrote:
>>> We've worked out the rough outline of how graceful shutdown will work in
>>> AS7.
>>> 
>>> The process of graceful shutdown actually is reflected by a number of
>>> states:
>>> 
>>> 1. Running - all services acting normally
>>> 2. Suspending - services refuse new "permits" (see below), existing
>>> permits are allowed to be retained (and threads running under such a
>>> permit may still acquire new permits)
>>> 3. Suspended - no permits are present and none may be issued
>>> 4. Shutting Down - our existing server stop process
>>> 
>>> The following transitions are allowed:
>>> 
>>> 1. Running → Suspending: Transition occurs at user request (to suspend
>>> or gracefully shut down).
>>> 2. Suspending → Suspended: Transition occurs when all permits are
>>> cleared.
>>> 3. Suspending → Running: Transition occurs at user request (to exit
>>> suspend mode or cancel graceful shutdown before it completes).
>>> 4. Suspended → Running: Transition occurs at user request (to exit
>>> suspend mode).
>>> 5. Suspended → Shutting Down: Transition occurs automatically (if a
>>> graceful shutdown was requested) or at user request (if a shut down
>>> request of any kind is entered in the Suspended state).
>>> 6. Running → Shutting Down: Transition occurs at user request (to shut
>>> down the server "un-gracefully").
>>> 
>>> These "permits" are issued by the "Shutdown Manager", whose job is to
>>> manage these states. They are issued corresponding to the following
>>> events:
>>> 
>>> 1. The invocation of an EJB method
>>> 2. The creation of a web session
>>> 3. A creation of a transaction
>>> 4. Probably some situations involving HQ and/or JCA
>>> 
>>> When a permit cannot be issued due to the server shutting down, a
>>> standard exception message should be produced so that the user can see a
>>> familiar error message regardless of what mechanism is used to access
>>> the server.
>>> 
>> 
> 
> 
> -- 
> - DML
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