Hi, Am Dienstag, den 05.07.2011, 12:50 +0100 schrieb Alasdair Nottingham: > Hi, > > This is amazing timing. I've hit exactly this problem while writing the code > for ARIES-686.
;-) > > I agree with your proposal, although when you describe 2 when you say you'll > look to see if the MBean implements a *MBean interface do you mean you will > use reflection, or look at the interfaces published into the service > registry? I think I'd like it to be the latter. If I drop the "(objectClass=*MBean)" term from the filter, I don't care for what is actually registered and the only means remaining is the jmx.objectname service property. Thus I use reflection. In any case, it seems to be essential to not require the *MBean interface to be exported by the MBean bundles (and consequently not to import them in the Whiteboard support bundle. But I could live well with using "(objectClass=*MBean)" (instead of (jmx.objectname=*)) as the filter and inspect the objectClass for the MBean interface. This would be closer to my original code ;-) Regards Felix > > Thanks > Alasdair > > On 5 July 2011 08:03, Felix Meschberger <[email protected]> wrote: > > > Hi, > > > > I think I missed a problematic point: Standard MBeans registered with > > the <classname>MBean pattern require that the implementation and the > > MBean interface reside in the same package. Not very practical for OSGi > > where the MBean interface of course must be exposed. > > > > So, I think we should probably drop the requirement for the MBean to > > exposed with an interface matching "*MBean". > > > > I still don't like to require the MBeanRegistration interface to be used > > in the registration. It is kind of like a helper interface not > > identifying the primary purpose of the MBean. > > > > How about changing the filter to just be (jmx.objectname=*). If the > > actual property is an empty string (or is not a single-value String), > > the object is expected to implement the MBeanRegistration interface. If > > not, an ERROR level message is logged and the service ignored. > > > > Now for the actual service object being registered: > > 1 if the service implements the DynamicMBean interface, use it > > right away as the object to register > > 2 otherwise see whether the object implements an interface whose > > name matches the <simple-class-name>MBean pattern. If so, wrap > > the object with a StandardMBean class using the interface as > > the MBean interface (and log this at INFO level) > > 3 otherwise log an ERROR level message and ignore the service > > > > Note that using the simple-class-name in the second step is a deviation > > from the JMX Spec which requires the MBean interface to reside in the > > same package as the MBean object. > > > > To make this work, the mbeanTracker ServiceTracker must be modified to > > actually track all services (this is a generic bug to be fixed, > > ARIES-700). > > > > Regards > > Felix > > > > Am Montag, den 27.06.2011, 20:45 +0100 schrieb Alasdair Nottingham: > > > On 27 June 2011 20:19, Felix Meschberger <[email protected]> wrote: > > > > > > > Hi, > > > > > > > > Am Montag, den 27.06.2011, 20:07 +0100 schrieb Alasdair Nottingham: > > > > > Hi, > > > > > > > > > > I've been looking at the way the whiteboard implementation works and > > I > > > > was > > > > > wondering if it would make sense to change the way it detects mbeans. > > > > > Currently it detects them by looking for: > > > > > > > > > > (objectClass=*MBean). The impl then needs to either have a > > jmx.objectname > > > > > property, or it needs to be javax.management.MBeanRegistration > > extension. > > > > I > > > > > > > > My idea for requiring some MBean interface is that it makes > > registration > > > > extremely easy: > > > > > > > > > > I agree with this goal. > > > > > > > > > > > > > > - either it is a DynamicMBean (or some extension thereof) service > > > > - or it is an interface with MBean suffix which as per the spec > > > > defines the MBean interface for the bean > > > > > > > > > > OK. > > > > > > > > > > > > > > For the registration then only an ObjectName is required which can be > > > > provided as a service registration property or by implementing the > > > > MBeanRegistration interface (which is also similarly used in the spec > > > > IIRC). > > > > > > > > > > > > > think it would make more sense for a service filter like this: > > > > > > > > > > (|(objectClass=javax.management.MBeanRegistration)(jmx.objectname=)) > > > > > > > > > > what do people think? > > > > > > > > By going that way, you will solve the second issue with the filter but > > > > you then have an MBean where you have to find out how to be able to > > > > register (or I may be missing something in more recent JMX specs). > > > > > > > > But then, I don't think we should require the MBeanRegistration > > > > interface as a service interface. Sounds kind of incorrect. > > > > > > > > > > I think if it needs to be an MBeanRegistration then we should require the > > > object to be advertised as an MBeanRegistration. Not putting > > > MBeanRegistration on a service and then relying on it being one is dodgy > > in > > > OSGi. Sure in most cases it'll work, but if someone decides to use > > service > > > hooks to insert a proxy they will probably get this wrong, also you can't > > > make use of the service registry to get the class space consistency. > > > > > > Overall based on this I think a more correct filter would be this: > > > > > > > > (&(objectClass=*MBean)(|(objectClass=javax.management.MBeanRegistration)(jmx.objectname=))) > > > > > > > > > > > > > > All in all, I think the original filter sounds more correct. > > > > > > > > Regards > > > > Felix > > > > > > > > > Alasdair > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
