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https://issues.apache.org/jira/browse/ARIES-1365?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=14709340#comment-14709340
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David Bosschaert commented on ARIES-1365:
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Hi [~joelrich],
I looked at your patch and have the following small thoughts/comments:
* I see that you use StateConfig as 2 services.
1. As a ManagedService to interact with ConfigAdmin.
2. As a StateConfig service to communicate the configuration to other parts of
the JMX implementation.
Option 1 above is definitely necessary, but I'm wondering whether option 2
makes things a little more complicated than needed. This is an object that you
just need to communicate to other parts of the JMX implementation. Would it
maybe be simpler to just pass the StateConfig service to the JMXAgentImpl
constructor in Activator.start() as you've just created it one line above. Then
in JMXAgentImpl you can pass the object to all the other classes that need it.
That would simplify the logic in those classes to deal with the StateConfig
service...
* I don't think we need the StateConfig.createConfiguration(). The
ManagedService.updated() callback is always made at least once, even if no
configuration is available. So you can simply set the default there if the
value didn't come in from the dictionary. So I would just remove that
createConfiguration() method...
* [nitpick] I see that in the Activator.stop() you explicitly unregister the
stateConfigService. This is not needed. Stopping a bundle will automatically
unregister its services.
> ServiceState attribute notifications slow down startup/shutdown time
> considerably
> ---------------------------------------------------------------------------------
>
> Key: ARIES-1365
> URL: https://issues.apache.org/jira/browse/ARIES-1365
> Project: Aries
> Issue Type: Bug
> Components: JMX
> Affects Versions: jmx-core-1.1.3
> Environment: org.apache.felix.framework 5.0.1
> Reporter: Joel Richard
> Assignee: David Bosschaert
> Labels: performance, shutdown, startup
> Attachments:
> 0001-ARIES-1365-ServiceState-attribute-notifications-slow.patch
>
>
> Around 20% of the startup time of our Felix OSGI container is spent creating
> attribute notifications for changed services in
> ServiceState#getAttributeChangeNotification. This is so slow because for each
> notification it calls bundleContext.getAllServiceReferences to get all
> service ids.
> Here a few suggestions how this could be improved:
> - The ServiceState could maintain its own list of service ids which is
> updated according to the service events
> - The ServiceState could implement the NotificationEmitter directly and be
> aware when there are any listeners (in our case, there are mostly none).
> - Make it possible to disable the attribute change notifications with
> configuration property.
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