RE: [jbosscache-dev] JMX and MBeans in JBoss Cache 2.0.0
Manik Surtani wrote:
> Brian Stansberry wrote:
>>
>> Now I'm no JMX expert and I may be talking nonsense here so feel
>> free to tear this apart. Brian, how would something like this work
>> for you since AS clustering gets cache references from JMX? Do we
>> still need to extend ServiceMBean in AS5?
>
> AS 5 services should be able to handle injection of pojos, so a cache
> instance won't even need to be an MBean. I'll be dealing with the
> cache via the Cache interface. The cache should just expose
> create(), start(), stop(), destroy(). Of course we want it to be an
> MBean for management purposes, but it doesn't have to be to be used
> by things like session replication.
>
So is is just those 4 that we want to expose via JMX then?
Ok, here is what I propose we expose via JMX:
1) lifecycle, as mentioned above.
2) API to get a List<ObjectName> of bound interceptor MBeans (is this
necessary/useful?) 3) API to get Configuration
4) API to dump cache contents/printLockInfo()
5) API to get a hold of the Cache interface, and using this
people have direct access to the cache rather than directly
exposing all of the cache methods via JMX.
A difficulty with a limited JMX interface that exposes complex objects
like Cache and Configuration is you have to be in the same JVM to make
use of the complex objects.
1) No manipulation via a browser (aka jmx-console and web-console).
2) No manipulation via RMIAdaptor (remote interface to JMX server.)
3) Don't know how the ON guys deal with the cache -- probably through
RMIAdaptor.
If Configuration is serializable it can be accessed in a read-only way
through RMIAdaptor. But are there any config attributes that should be
changeable at runtime (e.g. timeouts, eviction policy configs)?
Not being able to access the Cache via RMIAdaptor is going to break some
AS unit tests for sure.
It is possible as a workaround to bind a proxy to the cache in JNDI and
access it that way.
I'm sympathetic to the desire to reduce the # of exposed methods
(particularly all the Configuration ones), but gotta point out the
problems :)
I think this is something that should be brought up on the user forum so
as many users as possible get a chance to comment on how they deal with
JBC via JMX.