RFR: JDK-8173180 VirtualMachine.startLocalManagementAgent() returns URI with unreliable IP address

[Roger Riggs]

Hi,

I would expect to see a mix of versions in many operational cases. For 
example, in a large
deployment there will be a mix of versions active and the folks 
monitoring it should not
have to change their management tools unnecessarily.

The usual rule for interoperability between versions is that it should 
work between the
previous and next versions.  (+/- 1).

If there is any issue with compatibility between versions, you'll need 
to file a CCC
to make sure it gets adequate review.

Roger


On 6/20/17 7:42 AM, Ujwal Vangapally wrote:
> Thanks for the Review Daniel, Harsha.
>
> Yes with this fix JConsole running on JDK 8 won't be able to connect 
> to a process running on higher version of Java containing this change.
>
> I think even Harsha is agreeing this, his point is that the use case 
> where a client running on JDK 8 trying to connect to a process running 
> on latest releases is rare. As mostly for Local Management both client 
> and server will be running on same machine using same JDK for starting 
> both client and server .
>
> please correct me if this is not the case.
>
> can we have this fix with interoperability issue between versions ?
>
> Thanks,
>
> Ujwal.
>
>
>
> On 6/20/2017 2:40 PM, Daniel Fuchs wrote:
>> Hi Harsha,
>>
>> Maybe I'm missing something.
>> How is the local agent started?
>>
>> If it's started when you connect jconsole to a process
>> by specifying the process ID - then I suspect this will
>> prevent e.g. jconsole or jvisualvm running on JDK 8 to
>> connect to your process.
>>
>> Can you verify that it's not the case?
>>
>> best regards,
>>
>> -- daniel
>>
>> On 20/06/2017 09:11, Harsha Wardhana B wrote:
>>> Hi Daniel,
>>>
>>> The fix is applicable only to local JMX agent and the most common 
>>> use case would be client and server running from same JVM.
>>> It is highly unlikely that local JMX agent will be started to cater 
>>> for out-of-jvm clients.
>>>
>>> I don't see how introducing this fix can cause new interoperability 
>>> problems. Can you please elaborate?
>>>
>>> -Harsha
>>>
>>> On Monday 19 June 2017 10:23 PM, Daniel Fuchs wrote:
>>>> Hi,
>>>>
>>>> If I'm not mistaken then this will make it impossible
>>>> for earlier release to interoperate with newer releases
>>>> as the LocalRMIClientSocketFactory class will not be
>>>> present the client tries to deserialize the stub.
>>>>
>>>> best regards,
>>>>
>>>> -- daniel
>>>>
>>>> On 19/06/2017 11:52, Ujwal Vangapally wrote:
>>>>> Hi,
>>>>>
>>>>> Kindly review the fix for bug below
>>>>>
>>>>> https://bugs.openjdk.java.net/browse/JDK-8173180
>>>>>
>>>>> webrev: 
>>>>> http://cr.openjdk.java.net/~uvangapally/webrev/2017/8173180/webrev.00/ 
>>>>>
>>>>>
>>>>> Thanks,
>>>>>
>>>>> Ujwal
>>>>>
>>>>
>>>
>>
>