[jboss-jira] [JBoss JIRA] (AS7-5543) [7.1] Intermittent failure due to missing OSGi service

[Thomas Diesler (JIRA)]

     [ https://issues.jboss.org/browse/AS7-5543?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]

Thomas Diesler updated AS7-5543:
--------------------------------

        Fix Version/s: 7.1.3.Final (EAP)
                           (was: 7.2.0.Alpha1)
    Affects Version/s: 7.1.2.Final (EAP)

    
> [7.1] Intermittent failure due to missing OSGi service
> ------------------------------------------------------
>
>                 Key: AS7-5543
>                 URL: https://issues.jboss.org/browse/AS7-5543
>             Project: Application Server 7
>          Issue Type: Bug
>          Components: OSGi, Server
>    Affects Versions: 7.1.2.Final (EAP)
>            Reporter: Thomas Diesler
>            Assignee: David Lloyd
>            Priority: Critical
>             Fix For: 7.1.3.Final (EAP)
>
>
> For the first OSGi related deployments we intermittently see 
> {code}
> Services with missing/unavailable dependencies" =>
> ["jbosgi.integration.PersistentBundles.INSTALL 
> Missing[JBAS014861: <one or more transitive dependencies>]","jboss.deployment.unit.\"webapp.war\".REGISTER 
> {code}
> which is due to a race condition at subsystem startup.
> h4. Background
> At startup the framework goes through various phases
> # Framework.CREATE
> # Framework.INIT
> # Framework.ACTIVE
> During framework INIT persistent bundles (i.e. from a former run) are installed/started according to their persistent settings.
> In terms of services it means that the Framework.INIT service may depend on a number of Bundle.INSTALLED or Bundle.ACTIVE services. This however cannot be modelled as service dependencies because it must be possible to uninstall a persistent bundle (i.e. remove the Bundle.INSTALL) service without taking the framework down.
> Currently, we use a ServiceListener for the persistent Bundle services and install a PersistentBundles.COMPLETE service that Framework.INIT can actually depend on. 
> There is currently no guarantee that the PersistentBundles.COMPLETE service gets installed (and as a consequence that the Framework.INIT starts up) before the OSGi deployment does its phase checking for missing services.
> AFAICS, there is currently no way to model this type of dependency properly without having this race condition.
> A possible solution may be a notion of DependencyType.WEAK. The semantic would be a required dependency that can go away once the target service has reached its target state (or has failed)
> h4. Example
> * serviceA depends on serviceB with DependencyType.WEAK
> * serviceA starts when serviceB has started
> * serviceA stays UP when serviceB gets removed

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