On Fri, Dec 18, 2015 at 11:33 AM, Isuru Perera <[email protected]> wrote:
> Hi all, > > I'm trying to refactor code and move the initialization logic out from the > interceptors we have. i.e. MetricsInterceptor [1] and > HTTPMonitoringInterceptor [2]. With current lifecycle method support, we > can write some initialization code within the service only [3]. > Since we are very close to GA release, let's continue with current service lifecycle approach and finish refactoring of above 2 Interceptor as we planed, while we can continue this discussion separately. > > I understand that it's better to have a separate class for initialization > logic. But I need to make sure that initialization runs only once. That's > why I initially wrote the initialization logic at the interceptor level. > The user will add interceptor only once to the MSS application [4]. > > If there are multiple services (as in sample [4]], we cannot ask user to > initialize in each service as the initialization will run multiple times. > We can solve that by changing the initialization code to run once. But I > don't think that a good idea. There will be duplicate code in each service > to initialize Metrics and HTTP Monitoring. > Basically we have two deployment modes. 1.) Standalone service mode (aka MSS-lite) - In this mode we deploy single service per single application hence IMO service lifecycle annotations are sufficient because initialization code anyway run only one time. BTW did you find any use cases that we can't cover with service LC methods under this mode ? 2.) OSGi server mode Since this mode is based on OSGi, can't we just use OSGi features such as bundle activators, OSGi-service annotations[1] such as @Acitvate, @Deactivate instead of inventing something new ? We already use above OSGi features to register/deregister microservices, register/deregister Interceptor etc. [1] - https://kishanthan.wordpress.com/2014/03/29/using-annotation-with-osgi-declarative-services/ Thanks ! > > Is it possible to have lifecycle method support for the entire MSS > application as well? Something similar to ServletContextListener [5]? > > Thanks! > > Best Regards, > > [1] > https://github.com/wso2/product-mss/blob/v1.0.0-alpha/carbon-mss/components/org.wso2.carbon.mss/src/main/java/org/wso2/carbon/mss/metrics/MetricsInterceptor.java#L47-L85 > [2] > https://github.com/wso2/product-mss/blob/v1.0.0-alpha/carbon-mss/components/org.wso2.carbon.mss/src/main/java/org/wso2/carbon/mss/httpmonitoring/HTTPMonitoringInterceptor.java#L80-L196 > [3] https://github.com/wso2/product-mss/tree/master/samples/lifecycle > [4] > https://github.com/wso2/product-mss/blob/v1.0.0-alpha/samples/metrics/src/main/java/org/wso2/carbon/mss/example/Application.java#L39-L40 > [5] > http://docs.oracle.com/javaee/6/api/javax/servlet/ServletContextListener.html > > > > On Sun, Nov 15, 2015 at 7:46 PM, Sagara Gunathunga <[email protected]> > wrote: > >> >> >> On Sun, Nov 15, 2015 at 7:40 PM, Afkham Azeez <[email protected]> wrote: >> >>> Can you fix the metric code to ise this? >>> >> I can work with IsuruP, still metrics/DAS code are not familiar to me. >> >> Thanks ! >> >>> On Nov 15, 2015 6:32 PM, "Sagara Gunathunga" <[email protected]> wrote: >>> >>>> >>>> >>>> On Thu, Nov 12, 2015 at 8:41 PM, Afkham Azeez <[email protected]> wrote: >>>> >>>>> >>>>> >>>>> On Thu, Nov 12, 2015 at 5:05 AM, Sagara Gunathunga <[email protected]> >>>>> wrote: >>>>> >>>>>> Use case >>>>>> -------------- >>>>>> MS F/W should support at least two bean lifecycle methods so that one >>>>>> method get call during the service start-up while other one get call just >>>>>> before the service shutdown. We already have following use cases but this >>>>>> should be a much lengthy list when implementing real world use cases. >>>>>> >>>>>> 1) Service stat publishing - During the service start-up, it should >>>>>> be possible to initialize DAS agents and make connections, then during >>>>>> the >>>>>> service shutdown it should be possible to terminate DAS agents properly >>>>>> and >>>>>> close any connection remains. >>>>>> >>>>> >>>>> How are we doing the above now with the metrics component? >>>>> >>>> >>>> Initially IsuruP looked for such lifecycle extension points, but since >>>> it was not there it seems he has incorporated init logic into the >>>> constructor of the MetricsInterceptor, although it's not nice to mix >>>> separate aspect together technically it worked. Further there was no proper >>>> place to call any cleaning code during server shutdown. >>>> >>>> Thanks ! >>>> >>>> >>>>> >>>>> >>>>>> >>>>>> 2.) Metadata publishing - During the service start-up, it should be >>>>>> possible to publish service and endpoint metadata into a centralized >>>>>> metadata repository such as G-Reg and during the service shutdown it >>>>>> should >>>>>> be possible to remove/deactivate service or endpoint metadata on metadata >>>>>> repository. >>>>>> >>>>>> 3.) Handle connection establishment and termination for data sources >>>>>> such as RSBMS, LDAPs , legacy systems etc. >>>>>> >>>>>> >>>>>> Solution >>>>>> -------------- >>>>>> >>>>>> Instead of introducing our own proprietary approaches we could use >>>>>> @PostConstruct[1] and @PreDestroy[2] annotations available with JDK. >>>>>> Users just need to annotate their init and termination methods as >>>>>> follows. >>>>>> Additionally this is a natural choice for those who familiar with >>>>>> JAX-WS/JAX-RS programming models where above annotation are used for same >>>>>> purpose. >>>>>> >>>>>> @PostConstruct >>>>>> public void init() { >>>>>> LOG.info("Helloworld :: calling PostConstruct method"); >>>>>> } >>>>>> >>>>>> @PreDestroy >>>>>> public void close() { >>>>>> LOG.info("Helloworld :: calling PreDestroy method"); >>>>>> } >>>>>> >>>>>> >>>>>> I have added above 2 annotation support to MS trunk, please refer >>>>>> following working sample[3]. >>>>>> >>>>>> >>>>>> @IsuruP , since we have service lifecycle support now, we need to >>>>>> refactor your analytics sample to use proper annotations and it will >>>>>> become >>>>>> a real world sample as well, [3] is too simple to demonstrate real world >>>>>> use cases. >>>>>> >>>>>> >>>>>> [1] - >>>>>> https://docs.oracle.com/javaee/5/api/javax/annotation/PostConstruct.html >>>>>> [2] - >>>>>> https://docs.oracle.com/javaee/5/api/javax/annotation/PreDestroy.html >>>>>> [3] - >>>>>> https://github.com/wso2/product-mss/tree/master/samples/lifecycle >>>>>> >>>>>> >>>>>> Thanks ! >>>>>> -- >>>>>> Sagara Gunathunga >>>>>> >>>>>> Architect; WSO2, Inc.; http://wso2.com >>>>>> V.P Apache Web Services; http://ws.apache.org/ >>>>>> Linkedin; http://www.linkedin.com/in/ssagara >>>>>> Blog ; http://ssagara.blogspot.com >>>>>> >>>>>> >>>>> >>>>> >>>>> -- >>>>> *Afkham Azeez* >>>>> Director of Architecture; WSO2, Inc.; http://wso2.com >>>>> Member; Apache Software Foundation; http://www.apache.org/ >>>>> * <http://www.apache.org/>* >>>>> *email: **[email protected]* <[email protected]> >>>>> * cell: +94 77 3320919 <%2B94%2077%203320919>blog: * >>>>> *http://blog.afkham.org* <http://blog.afkham.org> >>>>> *twitter: **http://twitter.com/afkham_azeez* >>>>> <http://twitter.com/afkham_azeez> >>>>> *linked-in: **http://lk.linkedin.com/in/afkhamazeez >>>>> <http://lk.linkedin.com/in/afkhamazeez>* >>>>> >>>>> *Lean . Enterprise . Middleware* >>>>> >>>> >>>> >>>> >>>> -- >>>> Sagara Gunathunga >>>> >>>> Architect; WSO2, Inc.; http://wso2.com >>>> V.P Apache Web Services; http://ws.apache.org/ >>>> Linkedin; http://www.linkedin.com/in/ssagara >>>> Blog ; http://ssagara.blogspot.com >>>> >>>> >> >> >> -- >> Sagara Gunathunga >> >> Architect; WSO2, Inc.; http://wso2.com >> V.P Apache Web Services; http://ws.apache.org/ >> Linkedin; http://www.linkedin.com/in/ssagara >> Blog ; http://ssagara.blogspot.com >> >> > > > -- > Isuru Perera > Associate Technical Lead | WSO2, Inc. | http://wso2.com/ > Lean . Enterprise . Middleware > > about.me/chrishantha > Contact: +IsuruPereraWSO2 <https://www.google.com/+IsuruPereraWSO2/about> > -- Sagara Gunathunga Architect; WSO2, Inc.; http://wso2.com V.P Apache Web Services; http://ws.apache.org/ Linkedin; http://www.linkedin.com/in/ssagara Blog ; http://ssagara.blogspot.com
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