Re: jmx-dev JEP review : JDK-8171311 - REST APIs for JMX

[Harsha Wardhana B]

Hi Erik,

On Monday 11 September 2017 07:14 PM, Erik Gahlin wrote:
Hi Harsha,

I haven't looked at Jolokia, or know what is the most reasonable 
approach in this case, but as a principle, I think we should strive 
for the best possible design rather than trying to be compatible with 
third party tools.
Agreed. That will always be the first priority. That is the reason HTTP 
GET interfaces will not be changed. I am undecided if the POST payloads 
need to be changed (without compromising the REST design principles) to 
increase adoption of this feature.

How will the command line look like to start the agent with the rest 
adapter?

In the past there have been discussions about adding syntactic sugar 
for -Dcom.sun.management, i.e.

-Xmanagement:ssl=false,port=7091,authenticate=false

instead of

-Dcom.sun.management.jmxremote.ssl=false
-Dcom.sun.management.jmxremote.port=7091
-Dcom.sun.management.jmxremote.authenticate=false

which is hard to remember, cumbersome to write and error prone since 
the parameters are not validated. If we are adding support for REST, 
it could perhaps be default, i.e.

-Xmanagement:ssl=false,authenticate=false,port=80

If you want to use JMX over RMI you would specify protocol:

-Xmanagement:ssl=false,port=7091,authenticate=false,protocol=rmi
Yes. There is an enhancement request to add the -Xmanagemet:* syntatic 
sugar for -Dcom.sun.management.jmxremote.* flags. REST adapter will use 
one of the above flags though I haven't thought of the exact name for it 
yet. I will update the JEP with the details of the flag shortly.

Has there been any thoughts about JMX notifications?
Notifications will not be supported in this JEP.

 * MBean Notifications are not a widely used feature and will not be
   supported via the REST adapter.


I know it is outside the scope of the JEP, but I think we should take 
it into consideration when doing the design, so the functionality 
could be added on later without too much difficulty.
Notifications can be added without modifying the current design too 
much. If required, it will be worked upon via an enhancement request.

Thanks
Erik

Thanks
Harsha

Hi Martin,

In my opinion, the interfaces exposed by current JEP are lot closer 
to REST style than the interfaces exposed by Jolokia.

For instance, HTTP GET by default should be used to read resources, 
but it is made part of URL in Jolokia interfaces.

<base-url>/read/<mbean name>/<attribute name>/<inner path>

I would wait on opinions from more people before considering changing 
the current interfaces.

Thanks
-Harsha

On Wednesday 06 September 2017 11:40 AM, Martin Skarsaune wrote:
Hello

Would one at least consider adopting the same URL paths and payloads 
as Jolokia? This could make life a lot easier for third party tools 
that connect to it.

Best Regards

Martin Skarsaune

ons. 6. sep. 2017 kl. 07:04 skrev Harsha Wardhana B 
<harsha.wardhan...@oracle.com <mailto:harsha.wardhan...@oracle.com>>:

    Hi Kirk,

    Yes. Jolokia was considered and is listed as an alternative in
    the JEP.

      * Jolokia can serve as a viable alternative but can be bulky.
        We are looking for simple and lightweight solution.


    -Harsha

    On Wednesday 06 September 2017 10:21 AM, Kirk Pepperdine wrote:
    Hi,

    Have you run into this project?https://jolokia.org. Unfortunately it’s not 
exactly a drop in replacement for the standard RMI based JMX connector but it’s 
not far off.

    Kind regards,
    Kirk

    On Sep 5, 2017, at 6:30 PM, Erik Gahlin<erik.gah...@oracle.com> 
<mailto:erik.gah...@oracle.com>  wrote:

    Hi Harsha,

    Looping in jmx-dev.

    byte[], short[], int[], float[], double[]
    Should long[] be included there as well?

    The REST adapter will come with a simple and lightweight JSON parser.
    Is this an internal parser or will it be exposed as an API?

    If so, how does it relate to JEP 198: Light-Weight JSON API?
    http://openjdk.java.net/jeps/198

    Will com.sun.net.httpserver.HttpServer be used to serve the requests?

    Thanks
    Erik

    Hi All,

    Please review the JEP for REST APIs for JMX :
            https://bugs.openjdk.java.net/browse/JDK-8171311

    The JEP aims at providing RESTful web interfaces to MBeans.

    Access to MBeans registered in a MBeanServer running inside a JVM requires 
a Java client. Language-agnostic access to MBeans will require spawning a Java 
client which can be cumbersome. The proposed JEP allows MBeans to be accessed 
in a language/platform-independent, ubiquitous and seamless manner.

    Thanks
    -Harsha