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https://issues.apache.org/jira/browse/SOLR-1841?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
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Hoss Man updated SOLR-1841:
---------------------------

    Attachment: SOLR-1841.patch

Updated patch to work against trunk ... also tweaked the variable naming 
convention -- using "serverName" to refer to "object name used by the server" 
wsa confusing to me, so i switched it to a simpler "altName" convention.

Patrick: thanks for bringing this up ... i had no idea an MBeanServer was 
allowed to use a differnet ObjectName then the one specified.  (strictly 
speaking: i'm not sure if it is/isn't legal under the spec, but the Java API 
certianly seems to leave the possibly open, and as you say: Websphere seems to 
do this)

My only concern with this patch is that i think this new new Map<ObjectName, 
ObjectName> increases the thread un-safety of JmxMonitoredMap ... from what i 
can tell, it has never really ben very thread safe if two threads attempted to 
"put" with the same name concurrently -- but i believe the worst case scenario 
currently is that you get an exception (either from server.unregister because 
the other thread already unregistered the previous instance, or from 
server.register because the other thread already registered a different MBean 
with that name).  But with your patch, now (i thin) a new possibility will 
arise: that put() will exit "successfully", but with an ObjectName=>ObjectName 
recordd that doesn't corrispond with the bean mapping in the server -- which 
will make any subsequent put or unregister calls behave very oddly.

(i'm not 100% certain, but i think that's possible)

> Unregistering of Searcher MBean doesn't work in Websphere
> ---------------------------------------------------------
>
>                 Key: SOLR-1841
>                 URL: https://issues.apache.org/jira/browse/SOLR-1841
>             Project: Solr
>          Issue Type: Bug
>         Environment: Websphere Application Server 6.1
>            Reporter: Patrik Nordebo
>            Priority: Minor
>         Attachments: patch, SOLR-1841.patch
>
>
> On a Websphere cluster, all MBeans registered in the default MBean server get 
> renamed on registration (it adds properties based on which node and cell in 
> the Websphere cluster the process was running).  This means that when Solr 
> tries to unregister an MBean (e.g. an old searcher), the old MBean is never 
> removed.  In the case of a rebind the binding of the new MBean fails because 
> it tries to register a name that is already taken.
> To get around this the name the mbean gets assigned must be stored somewhere 
> where it can be looked up when we need to remove the binding.

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