Hi All,
While reading through this thread again, I understood that we might be
talking two different things here. So I thought to explain the difference
between Maven modules and Modular( Separation of Concern) in Component
based architecture. What I am suggesting is restructure maven modules not
to change existing Modular concept. If anyone say making one maven module
call "core" by putting all basic interfaces together will break Modular
concept in Component based architecture, that is not true. These are two
different concepts. While component based architecture is software
engineering architectural design, Maven is used to project management.
Component based architecture may or may not have one maven module "core" in
project which has all basic interfaces. If this core maven module is so
complex then it is worth to break it to few modules. But for Airavata this
doesn't relate, as suggested core maven module is not that complex.
Thanks,
Shameera.
On Mon, Jun 1, 2015 at 9:09 PM, Shameera Rathnayaka <shameerai...@gmail.com>
wrote:
> Hi Raminder,
>
> Different implementations can depend on different versions of the same
> jar, as we are using native java class loading, it doesn't support
> different versions to class loaded and live in one runtime, unless we come
> up with OSGi like modular system or customize class loader behavior which
> is tricky. If we are getting this issue with basic Airavata components then
> we should fix this and use one version through all the components. If
> different plugable implementations use different versions then both can't
> work together only one version will be class loaded, this is a known
> restriction. Anyway I am not suggesting to have one bulky Maven module, we
> should have some level of categorization. If any interface has different
> implementations and those are distinct enough, then having different
> modules make sense.
>
> Definitely we must remove implementation classes from current core
> modules. With multiplex thrift support which Suresh is working on, for me
> it make sense to have all services in one maven module call "service".
> Anyway let's think other alternatives too.
>
> Thanks,
> Shameera.
>
> On Mon, Jun 1, 2015 at 1:25 PM, Raminderjeet Singh <
> raminderjsi...@gmail.com> wrote:
>
>> Hi Shameera,
>>
>> I think, we are tying to deal with 2 problems. Code manageability/usage
>> and distribution.
>>
>> In GFAC, I noticed that there is a dependencies on modules, which should
>> not exist like GFAC's GSISSH module dependent on SSH module and both the
>> modules depending on GSISSH library. Reason of such depend is duplication
>> of utility methods (see GFACSSHUtils and GFACGSISSHUtils for duplicate
>> code) in both of these modules and we need to fix it. I think there are
>> similar examples in different modules. According to me, if 60% code is
>> duplicate, we need to merge the module as one or come. Other way of saying
>> is we should only create an module when its needed. Local,SSH,GSISSH should
>> not be separate modules as they have lot in common. Just to give you some
>> background on GFAC modules, they were created for the purpose of having
>> different flavors of GFAC. This was mainly done to fix the problem of jar
>> dependencies (different security dependencies) of GFAC modules in a JVM. It
>> was effecting modules to work together. An example in the past was,
>> Unicore, GRAM and GSISSH modules did not work together so we had to spend
>> time to inspect distribution to find which runtime dependency is causing
>> problem and fix it. With the current design we can create individual
>> version of GFAC. We still need to enhance GFAC service to have a flavor of
>> GFAC registered with type and route the jobs. So we need some of this
>> flavoring support in GFAC.
>>
>> I agree with you that we have too many core modules and in core
>> modules like GFAC core, we have implementations (e.g. BetterGFACImpl). We
>> should move implementations to Gfac service. Lets talk about pros and cons
>> about having a single core and then we can decide how to proceed. Currently
>> airavata does not provide a single view to all of its functionality. API
>> server was designed to do that but its also overloaded with lot of
>> implementation details. If I am following your advice right, having a
>> common airavata core will definitely help developer to think about airavata
>> as a system and design new components with system prospective so +1 for
>> something like this. Only drawback can be, taking away some flexibly from a
>> component developer, which is anyhow good for airavata system point of
>> view. Before we just into conclusion, We need to just evaluate how it will
>> work with our thrift services design.
>>
>> Thanks
>> Raminder
>>
>>
>>
>> On Sat, May 30, 2015 at 11:55 PM, Shameera Rathnayaka <
>> shameerai...@gmail.com> wrote:
>>
>>> Hi Suresh,
>>>
>>> You are thinking about deployment perspective while I am thinking about
>>> dependency issue. With my suggestion for each component distribution will
>>> be increased by less than 1MB, because only the interfaces are in the
>>> core. And in runtime those interfaces will not be loaded. Thinking the
>>> trouble we are getting at development time and code maintain issues. I
>>> think we can bare with that 1MB.
>>>
>>> Thanks,
>>> Shameera.
>>>
>>> On Sat, May 30, 2015 at 10:45 PM, Suresh Marru <sma...@apache.org>
>>> wrote:
>>>
>>>> Shameera,
>>>>
>>>> Every component has in its own thrift service interface (registry and
>>>> messaging have exceptions). Every component will need to have a dependency
>>>> to airavata data models (which includes util classes) and probably registry
>>>> and messaging. if a component A needs to invoke component B via RPC call,
>>>> then it just needs to include its component A’s thrift client. If the
>>>> communication is through work queue’s then there is no dependency between
>>>> them. Can you describe what you want to propose in this context?
>>>>
>>>> Suresh
>>>>
>>>> On May 30, 2015, at 8:36 PM, Shameera Rathnayaka <
>>>> shameerai...@gmail.com> wrote:
>>>>
>>>> Hi Suresh,
>>>>
>>>>>
>>>>> Spark is not the right comparison for this discussion. I have been a
>>>>> spark incubation mentor and have been following the code organization
>>>>> since
>>>>> its early days. All of the spark components you mentions rely on the core.
>>>>>
>>>>
>>>> Yes, that is what I highlight , each components doesn't have their own
>>>> core modules which has the interfaces. Spark SQL module has core submodule
>>>> but all interfaces reside in main core module.
>>>>
>>>>
>>>>> Let me step back and ask, what is the problem you are trying to solve?
>>>>> We sure need to cleanup modules and it is time to re-look at the component
>>>>> organization. But what do you want to really achieve by combining all the
>>>>> core into monolithic components. It took an effort to cleanly separate
>>>>> functionality so they can evolve and can be improved independently.
>>>>>
>>>>
>>>>
>>>> I am not suggesting to go back to the monolithic core which has all
>>>> implementations and interfaces bundle with together. What i am saying is
>>>> have core interfaces all together, this will give us clear module
>>>> dependency graph. This is something like having one root dependency graph
>>>> instead of multiple roots. As a developer it is cumbersome and hard to deal
>>>> with module dependency issues. Having too fine gran core modules introduce
>>>> wrong dependency graph eventually, and it will prevent us to follow proper
>>>> design patterns in our code base. If we avoid design patterns, it will
>>>> require more time to find bugs and maintain. This is what I am trying to
>>>> resolve. I have first hand experiences with current airavata code. If you
>>>> see the current module dependency graphs, then you will understand why I am
>>>> making such noise to resolve this.
>>>>
>>>>
>>>>> So why do we make our repository bulky with modules unless it doesn't
>>>>> provide any considerable advantage.
>>>>>
>>>>> If we really w
>>>>> ant to
>>>>> separate distribution bundle for each component ( apiServer ,
>>>>> Orchestrator and Gfac ) let
>>>>> '
>>>>> s use different bin.xml file
>>>>> s
>>>>> to do it instead of using different modules. But reality is we only
>>>>> use all in one distribution.
>>>>>
>>>>>
>>>>> Once the monitoring is fixed to use messaging, we really need to
>>>>> decouple the component deployments. Yes there is a considerable advantage.
>>>>> Each components has different quality of service requirements. A
>>>>> production
>>>>> platform has to load balance and scale horizontally. And thats different
>>>>> for different component. The all in one bundle has 300+ jars, but API
>>>>> server and orchestrator when independent will have around 50 or so jars.
>>>>> When I want to deploy api server and orchestrator there is significant
>>>>> different in small light weight components vs one monolithic core.
>>>>>
>>>>> Another problem is component evolution. Lets say there is a production
>>>>> deployment running 1.1.4 version. Lets say the single job execution is
>>>>> stable enough and there is a 6 month focused effort on workflow. Say the
>>>>> master moves to 1.2.8 with all the changes to workflow and only few to
>>>>> single application execution. We can more comfortably upgrade is they are
>>>>> cleanly separated modules. But if it is one core and so many changes to it
>>>>> (even though technically they are to different classes, the perception
>>>>> will
>>>>> remain), the upgrades will get behind.
>>>>>
>>>>> Bottom line I am + 1 for cleaning up the modules. Past few years we
>>>>> have been moving towards micro service architectures and your suggestions
>>>>> will reverse this back to monolithic architecture. I am -1 for this change
>>>>> in direction.
>>>>>
>>>>
>>>>
>>>> By looking at your miniature component suggestion above, it has 30+
>>>> modules. Do you think we really need this number of categorization? With my
>>>> industrial experience, I have seen
>>>> number of modules in a project always increase with time. Hence
>>>> If we start 30+ we will come to 40+ and then 50+
>>>> and so on so forth
>>>> . Why we make this complicated?
>>>>
>>>> Thanks,
>>>> Shameera.
>>>>
>>>>
>>>>
>>>>>
>>>>> Suresh
>>>>>
>>>>>
>>>>> Thanks,
>>>>> Shameera.
>>>>>
>>>>>
>>>>>>
>>>>>> Suresh
>>>>>>
>>>>>> On May 29, 2015, at 11:29 AM, Suresh Marru <sma...@apache.org> wrote:
>>>>>>
>>>>>> + 1.
>>>>>>
>>>>>> I was planning to bring up this issue also. Probably it will not
>>>>>> address what you are raising, but here is a tree output from airavata
>>>>>> labs
>>>>>> code I was toying with locally. I did not yet compare it with what you
>>>>>> proposed, I will do so later today.
>>>>>>
>>>>>> ├── airavata-api
>>>>>> │ ├── airavata-api-interface-descriptions
>>>>>> │ ├── airavata-api-java-stubs
>>>>>> │ ├── airavata-api-server
>>>>>> │ ├── airavata-data-models
>>>>>> │ ├── api-security-manager
>>>>>> ├── clients
>>>>>> │ ├── airavata-client-cpp-sdk
>>>>>> │ ├── airavata-client-java-sdk
>>>>>> │ ├── airavata-client-php-sdk
>>>>>> │ ├── airavata-client-python-sdk
>>>>>> │ ├── airavata-sample-examples
>>>>>> │ └── airavata-xbaya-gui
>>>>>> ├── components
>>>>>> │ ├── commons
>>>>>> │ ├── component-interface-descriptions
>>>>>> │ ├── component-services
>>>>>> │ │ ├── credential-store-service
>>>>>> │ │ ├── orchestrator-service
>>>>>> │ │ ├── task-executor-service
>>>>>> │ │ └── workflow-interpreter-service
>>>>>> │ ├── component-clients
>>>>>> │ │ ├── credential-store-client
>>>>>> │ │ ├── orchestrator-client
>>>>>> │ │ ├── task-executor-client
>>>>>> │ │ ├── workflow-interpreter-client
>>>>>> │ │ └── messaging
>>>>>> │ ├── task-adaptors
>>>>>> │ │ ├── compute
>>>>>> │ │ └── data-movement
>>>>>> │ ├── registry
>>>>>> │ │ ├── app-catalog
>>>>>> │ │ ├── experiment-catalog
>>>>>> │ │ └── resource-catalog
>>>>>> │ └── workflow-interpreter
>>>>>> ├── distribution
>>>>>> ├── integration-tests
>>>>>>
>>>>>>
>>>>>>
>>>>>> On May 29, 2015, at 10:15 AM, Shameera Rathnayaka <
>>>>>> shame...@apache.org> wrote:
>>>>>>
>>>>>> Hi Devs,
>>>>>>
>>>>>> As we are using different modules to package different type of
>>>>>> functionalities, which will help us to maintain loosely couple codes. Now
>>>>>> the project has 49 leaf module ( one to hit half century :) ). If we
>>>>>> allow
>>>>>> project to grow this way, having too fine grain modules will be huge
>>>>>> headache in future. IMO we should clean this ASAP before it become really
>>>>>> mess. Actually we half way there, I experienced cyclic dependency issues
>>>>>> when I was writing workflow implementation and email monitoring. Please
>>>>>> see
>>>>>> the modules in current repo below.
>>>>>>
>>>>>> <module-name> ( <num of child modules> )
>>>>>>
>>>>>> modules ( 43 )
>>>>>> app-catalog ( 2 )
>>>>>> commons ( 1 )
>>>>>> configurations ( 2 )
>>>>>> credential-store ( 3 )
>>>>>> distribution ( 8 )
>>>>>> gfac ( 10 )
>>>>>> integration test ( 1 )
>>>>>> messaging ( 2 )
>>>>>> orchestrator ( 3 )
>>>>>> registry ( 3 )
>>>>>> security ( 1 )
>>>>>> server ( 1 )
>>>>>> test-suit ( 1 )
>>>>>> workflow ( 1 )
>>>>>> workflow-modal ( 3 )
>>>>>> xbaya ( 1 )
>>>>>> airavata-api ( 5 )
>>>>>> tools ( 1 )
>>>>>>
>>>>>> Most of the current modules have interfaces and implementations
>>>>>> together, but this violate our main goal which reduce inter module
>>>>>> dependencies. Following is what I am suggesting, WDYS?
>>>>>>
>>>>>> core { has all core interfaces and basic classes of gfac-core ,
>>>>>> orchestrator-core , message-core , monitor core, registry core,
>>>>>> workflow-core}
>>>>>> service - all thrift services and service handlers
>>>>>> orchestrator - orchestrator specific classes
>>>>>> gfac
>>>>>> SSH
>>>>>> BES
>>>>>> Local
>>>>>> message - amqp implemention
>>>>>> distribution
>>>>>> XBaya
>>>>>> server - { use different mode input to start server as
>>>>>> orchestrator , Gfac or/and api-server }
>>>>>> commons
>>>>>> registry
>>>>>> app-catalog
>>>>>> security
>>>>>> Workflow
>>>>>> XBaya-gui
>>>>>> Integration-test
>>>>>>
>>>>>> Thanks,
>>>>>> Shameera.
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> Best Regards,
>>>>> Shameera Rathnayaka.
>>>>>
>>>>> email: shameera AT apache.org , shameerainfo AT gmail.com
>>>>> Blog : http://shameerarathnayaka.blogspot.com/
>>>>>
>>>>>
>>>>>
>>>>
>>>>
>>>> --
>>>> Best Regards,
>>>> Shameera Rathnayaka.
>>>>
>>>> email: shameera AT apache.org , shameerainfo AT gmail.com
>>>> Blog : http://shameerarathnayaka.blogspot.com/
>>>>
>>>>
>>>>
>>>
>>>
>>> --
>>> Best Regards,
>>> Shameera Rathnayaka.
>>>
>>> email: shameera AT apache.org , shameerainfo AT gmail.com
>>> Blog : http://shameerarathnayaka.blogspot.com/
>>>
>>
>>
>
>
> --
> Best Regards,
> Shameera Rathnayaka.
>
> email: shameera AT apache.org , shameerainfo AT gmail.com
> Blog : http://shameerarathnayaka.blogspot.com/
>
--
Best Regards,
Shameera Rathnayaka.
email: shameera AT apache.org , shameerainfo AT gmail.com
Blog : http://shameerarathnayaka.blogspot.com/
