Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Afkham Azeez]

This is how any type of cache generally works. For example, a Web server
proxy cache may serve requests from the cache, if the requested resources
are available in the cache, but if a non-existent resource is requested, and
the target server is down, the request would return an error to the client
for that particular request.


On Fri, Apr 22, 2011 at 7:52 PM, Supun Kamburugamuva  wrote:

> On Fri, Apr 22, 2011 at 7:43 PM, Afkham Azeez  wrote:
> > Yes, it is consistent. The cache has a cache timeout, and as long as the
> > items in the cache are fresh, regardless of the DB being available or
> not,
> > it is correct to serve from the cache.
>
> The inconsistency I point out is regarding two resources. If one
> resource is available when the db is down and and other is not
> available, it is not consistent from the users perspective, specially
> when he can't choose to have caching from the registry APIs. If user
> explicitly says in his program that caching is required then it is
> consistent. But if it happens under the hood without user control
> through APIs, it seems in-consistent.
>
> Thanks,
> Supun..
>
> >
> > On Fri, Apr 22, 2011 at 7:21 PM, Senaka Fernando 
> wrote:
> >>
> >> Hi Supun,
> >>
> >> From a Caching PoV, this is consistent. DB-loss can be momentary or
> >> pro-longed, but that's not a concern of a cache. And, the prime use-case
> of
> >> the cache is to make it possible to fetch cached resources instead of
> making
> >> DB-calls. I see no inconsistency in this model, as Sumedha pointed out
> >> earlier.
> >>
> >> Proper exceptions are thrown when there is a loss of DB connectivity, if
> a
> >> programmer needs to figure a loss of DB-connectivity (you can check the
> >> cause - which is a Throwable; of the exception that's thrown by the
> >> registry). But, to me, this is an edge-case, and if there is such a
> >> consistency requirement the cache can be disabled. By default, caching
> is
> >> enabled, and the changes have been made to the registry.xml files found
> in
> >> carbon core, and files used for testing in carbon components and also at
> >> product-level.
> >>
> >> Thanks,
> >> Senaka.
> >>
> >> On Fri, Apr 22, 2011 at 5:11 PM, Supun Kamburugamuva 
> >> wrote:
> >>>
> >>> Having Caching for fail cases transparently from the user gives an in
> >>> consistency. Lets say a user accessed a resource before the registry
> >>> database failed. After the registry database has failed, user can
> >>> access this particular resource but he may not be able to access
> >>> another resource. From a programmers perspective this is not
> >>> consistent.
> >>>
> >>> Thanks,
> >>> Supun..
> >>>
> >>> On Fri, Apr 22, 2011 at 4:58 PM, Afkham Azeez  wrote:
> >>> >
> >>> >
> >>> > On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu 
> >>> > wrote:
> >>> >>
> >>> >>
> >>> >> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe  >
> >>> >> wrote:
> >>> >>>
> >>> >>>
> >>> >>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva <
> su...@wso2.com>
> >>> >>> wrote:
> >>> 
> >>>  For the users of the registry, it is important to know weather
> >>>  registry database is down.
> >>> 
> >>>  For example we have the requirement of caching the resources at
> >>>  theimplemtation
> >>>  ESB level and manage these caches according to the ESB specific
> >>>  configurations. So I believe we have implemented something that
> >>>  should
> >>>  have being implemented at the application layer at the registry
> >>>  level.
> >>> 
> >>>  The correct way to implement this kind of functionalities in the
> >>>  registry is using an adapter kind of approach. If a user wants
> >>>  registry resource caching they can use a adapter to access the
> >>>  registry instead of direct access.
> >>> >>>
> >>> >>> Or we may introduce a mechanism to disable registry caching. In the
> >>> >>> current implementation there is no way to disable registry caching.
> >>> >>
> >>> >> AFAIK Senaka did some changes recently and made registry caching
> >>> >> configurable. Also with the default configuration registry caching
> is
> >>> >> disabled.
> >>> >
> >>> > default should be caching enabled.
> >>> >
> >>> >>
> >>> >> Thanks,
> >>> >> Janaka
> >>> >>>
> >>> >>> Thanks,
> >>> >>> Waruna
> >>> >>>
> >>> 
> >>>  Thanks,
> >>>  Supun..
> >>> 
> >>>  On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe
> >>>  
> >>>  wrote:
> >>>  > How else would you expect a cache to behave? ;-)
> >>>  > /sumedha
> >>>  >
> >>>  > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva
> >>>  > 
> >>>  > wrote:
> >>>  >>
> >>>  >> I tried to shut down the registry database and access the
> >>>  >> registry
> >>>  >> resources. It seems, even though the database is down registry
> is
> >>>  >> serving the resources from a cache. Is this the behavior of the
> >>>  >> registry?
> >>>  >>
> >>>  >> Thanks,
> >>>  >> --
> 

Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Supun Kamburugamuva]

On Fri, Apr 22, 2011 at 7:43 PM, Afkham Azeez  wrote:
> Yes, it is consistent. The cache has a cache timeout, and as long as the
> items in the cache are fresh, regardless of the DB being available or not,
> it is correct to serve from the cache.

The inconsistency I point out is regarding two resources. If one
resource is available when the db is down and and other is not
available, it is not consistent from the users perspective, specially
when he can't choose to have caching from the registry APIs. If user
explicitly says in his program that caching is required then it is
consistent. But if it happens under the hood without user control
through APIs, it seems in-consistent.

Thanks,
Supun..

>
> On Fri, Apr 22, 2011 at 7:21 PM, Senaka Fernando  wrote:
>>
>> Hi Supun,
>>
>> From a Caching PoV, this is consistent. DB-loss can be momentary or
>> pro-longed, but that's not a concern of a cache. And, the prime use-case of
>> the cache is to make it possible to fetch cached resources instead of making
>> DB-calls. I see no inconsistency in this model, as Sumedha pointed out
>> earlier.
>>
>> Proper exceptions are thrown when there is a loss of DB connectivity, if a
>> programmer needs to figure a loss of DB-connectivity (you can check the
>> cause - which is a Throwable; of the exception that's thrown by the
>> registry). But, to me, this is an edge-case, and if there is such a
>> consistency requirement the cache can be disabled. By default, caching is
>> enabled, and the changes have been made to the registry.xml files found in
>> carbon core, and files used for testing in carbon components and also at
>> product-level.
>>
>> Thanks,
>> Senaka.
>>
>> On Fri, Apr 22, 2011 at 5:11 PM, Supun Kamburugamuva 
>> wrote:
>>>
>>> Having Caching for fail cases transparently from the user gives an in
>>> consistency. Lets say a user accessed a resource before the registry
>>> database failed. After the registry database has failed, user can
>>> access this particular resource but he may not be able to access
>>> another resource. From a programmers perspective this is not
>>> consistent.
>>>
>>> Thanks,
>>> Supun..
>>>
>>> On Fri, Apr 22, 2011 at 4:58 PM, Afkham Azeez  wrote:
>>> >
>>> >
>>> > On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu 
>>> > wrote:
>>> >>
>>> >>
>>> >> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe 
>>> >> wrote:
>>> >>>
>>> >>>
>>> >>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva 
>>> >>> wrote:
>>> 
>>>  For the users of the registry, it is important to know weather
>>>  registry database is down.
>>> 
>>>  For example we have the requirement of caching the resources at
>>>  theimplemtation
>>>  ESB level and manage these caches according to the ESB specific
>>>  configurations. So I believe we have implemented something that
>>>  should
>>>  have being implemented at the application layer at the registry
>>>  level.
>>> 
>>>  The correct way to implement this kind of functionalities in the
>>>  registry is using an adapter kind of approach. If a user wants
>>>  registry resource caching they can use a adapter to access the
>>>  registry instead of direct access.
>>> >>>
>>> >>> Or we may introduce a mechanism to disable registry caching. In the
>>> >>> current implementation there is no way to disable registry caching.
>>> >>
>>> >> AFAIK Senaka did some changes recently and made registry caching
>>> >> configurable. Also with the default configuration registry caching is
>>> >> disabled.
>>> >
>>> > default should be caching enabled.
>>> >
>>> >>
>>> >> Thanks,
>>> >> Janaka
>>> >>>
>>> >>> Thanks,
>>> >>> Waruna
>>> >>>
>>> 
>>>  Thanks,
>>>  Supun..
>>> 
>>>  On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe
>>>  
>>>  wrote:
>>>  > How else would you expect a cache to behave? ;-)
>>>  > /sumedha
>>>  >
>>>  > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva
>>>  > 
>>>  > wrote:
>>>  >>
>>>  >> I tried to shut down the registry database and access the
>>>  >> registry
>>>  >> resources. It seems, even though the database is down registry is
>>>  >> serving the resources from a cache. Is this the behavior of the
>>>  >> registry?
>>>  >>
>>>  >> Thanks,
>>>  >> --
>>>  >> Supun Kamburugamuva
>>>  >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>>>  >> Member, Apache Software Foundation; http://www.apache.org
>>>  >> WSO2 Inc.;  http://wso2.org
>>>  >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>>>  >> Blog: http://supunk.blogspot.com
>>>  >> ___
>>>  >> Carbon-dev mailing list
>>>  >> Carbon-dev@wso2.org
>>>  >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>>  >
>>>  >
>>>  > ___
>>>  > Carbon-dev mailing list
>>>  > Carbon-dev@wso2.org
>>> 

Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Afkham Azeez]

Yes, it is consistent. The cache has a cache timeout, and as long as the
items in the cache are fresh, regardless of the DB being available or not,
it is correct to serve from the cache.

On Fri, Apr 22, 2011 at 7:21 PM, Senaka Fernando  wrote:

> Hi Supun,
>
> From a Caching PoV, this is consistent. DB-loss can be momentary or
> pro-longed, but that's not a concern of a cache. And, the prime use-case of
> the cache is to make it possible to fetch cached resources instead of making
> DB-calls. I see no inconsistency in this model, as Sumedha pointed out
> earlier.
>
> Proper exceptions are thrown when there is a loss of DB connectivity, if a
> programmer needs to figure a loss of DB-connectivity (you can check the
> cause - which is a Throwable; of the exception that's thrown by the
> registry). But, to me, this is an edge-case, and if there is such a
> consistency requirement the cache can be disabled. By default, caching is
> enabled, and the changes have been made to the registry.xml files found in
> carbon core, and files used for testing in carbon components and also at
> product-level.
>
> Thanks,
> Senaka.
>
>
> On Fri, Apr 22, 2011 at 5:11 PM, Supun Kamburugamuva wrote:
>
>> Having Caching for fail cases transparently from the user gives an in
>> consistency. Lets say a user accessed a resource before the registry
>> database failed. After the registry database has failed, user can
>> access this particular resource but he may not be able to access
>> another resource. From a programmers perspective this is not
>> consistent.
>>
>> Thanks,
>> Supun..
>>
>> On Fri, Apr 22, 2011 at 4:58 PM, Afkham Azeez  wrote:
>> >
>> >
>> > On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu 
>> wrote:
>> >>
>> >>
>> >> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe 
>> >> wrote:
>> >>>
>> >>>
>> >>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva 
>> >>> wrote:
>> 
>>  For the users of the registry, it is important to know weather
>>  registry database is down.
>> 
>>  For example we have the requirement of caching the resources at
>>  theimplemtation
>>  ESB level and manage these caches according to the ESB specific
>>  configurations. So I believe we have implemented something that
>> should
>>  have being implemented at the application layer at the registry
>> level.
>> 
>>  The correct way to implement this kind of functionalities in the
>>  registry is using an adapter kind of approach. If a user wants
>>  registry resource caching they can use a adapter to access the
>>  registry instead of direct access.
>> >>>
>> >>> Or we may introduce a mechanism to disable registry caching. In the
>> >>> current implementation there is no way to disable registry caching.
>> >>
>> >> AFAIK Senaka did some changes recently and made registry caching
>> >> configurable. Also with the default configuration registry caching is
>> >> disabled.
>> >
>> > default should be caching enabled.
>> >
>> >>
>> >> Thanks,
>> >> Janaka
>> >>>
>> >>> Thanks,
>> >>> Waruna
>> >>>
>> 
>>  Thanks,
>>  Supun..
>> 
>>  On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe <
>> sume...@wso2.com>
>>  wrote:
>>  > How else would you expect a cache to behave? ;-)
>>  > /sumedha
>>  >
>>  > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva <
>> su...@wso2.com>
>>  > wrote:
>>  >>
>>  >> I tried to shut down the registry database and access the registry
>>  >> resources. It seems, even though the database is down registry is
>>  >> serving the resources from a cache. Is this the behavior of the
>>  >> registry?
>>  >>
>>  >> Thanks,
>>  >> --
>>  >> Supun Kamburugamuva
>>  >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>>  >> Member, Apache Software Foundation; http://www.apache.org
>>  >> WSO2 Inc.;  http://wso2.org
>>  >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>>  >> Blog: http://supunk.blogspot.com
>>  >> ___
>>  >> Carbon-dev mailing list
>>  >> Carbon-dev@wso2.org
>>  >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>  >
>>  >
>>  > ___
>>  > Carbon-dev mailing list
>>  > Carbon-dev@wso2.org
>>  > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>  >
>>  >
>> 
>> 
>> 
>>  --
>>  Supun Kamburugamuva
>>  Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>>  Member, Apache Software Foundation; http://www.apache.org
>>  WSO2 Inc.;  http://wso2.org
>>  E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>>  Blog: http://supunk.blogspot.com
>>  ___
>>  Carbon-dev mailing list
>>  Carbon-dev@wso2.org
>>  http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>> >>>
>> >>>
>> >>>
>> >>> --
>> >>>
>> -

Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Senaka Fernando]

Hi Supun,

>From a Caching PoV, this is consistent. DB-loss can be momentary or
pro-longed, but that's not a concern of a cache. And, the prime use-case of
the cache is to make it possible to fetch cached resources instead of making
DB-calls. I see no inconsistency in this model, as Sumedha pointed out
earlier.

Proper exceptions are thrown when there is a loss of DB connectivity, if a
programmer needs to figure a loss of DB-connectivity (you can check the
cause - which is a Throwable; of the exception that's thrown by the
registry). But, to me, this is an edge-case, and if there is such a
consistency requirement the cache can be disabled. By default, caching is
enabled, and the changes have been made to the registry.xml files found in
carbon core, and files used for testing in carbon components and also at
product-level.

Thanks,
Senaka.

On Fri, Apr 22, 2011 at 5:11 PM, Supun Kamburugamuva  wrote:

> Having Caching for fail cases transparently from the user gives an in
> consistency. Lets say a user accessed a resource before the registry
> database failed. After the registry database has failed, user can
> access this particular resource but he may not be able to access
> another resource. From a programmers perspective this is not
> consistent.
>
> Thanks,
> Supun..
>
> On Fri, Apr 22, 2011 at 4:58 PM, Afkham Azeez  wrote:
> >
> >
> > On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu 
> wrote:
> >>
> >>
> >> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe 
> >> wrote:
> >>>
> >>>
> >>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva 
> >>> wrote:
> 
>  For the users of the registry, it is important to know weather
>  registry database is down.
> 
>  For example we have the requirement of caching the resources at
>  theimplemtation
>  ESB level and manage these caches according to the ESB specific
>  configurations. So I believe we have implemented something that should
>  have being implemented at the application layer at the registry level.
> 
>  The correct way to implement this kind of functionalities in the
>  registry is using an adapter kind of approach. If a user wants
>  registry resource caching they can use a adapter to access the
>  registry instead of direct access.
> >>>
> >>> Or we may introduce a mechanism to disable registry caching. In the
> >>> current implementation there is no way to disable registry caching.
> >>
> >> AFAIK Senaka did some changes recently and made registry caching
> >> configurable. Also with the default configuration registry caching is
> >> disabled.
> >
> > default should be caching enabled.
> >
> >>
> >> Thanks,
> >> Janaka
> >>>
> >>> Thanks,
> >>> Waruna
> >>>
> 
>  Thanks,
>  Supun..
> 
>  On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe  >
>  wrote:
>  > How else would you expect a cache to behave? ;-)
>  > /sumedha
>  >
>  > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva <
> su...@wso2.com>
>  > wrote:
>  >>
>  >> I tried to shut down the registry database and access the registry
>  >> resources. It seems, even though the database is down registry is
>  >> serving the resources from a cache. Is this the behavior of the
>  >> registry?
>  >>
>  >> Thanks,
>  >> --
>  >> Supun Kamburugamuva
>  >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>  >> Member, Apache Software Foundation; http://www.apache.org
>  >> WSO2 Inc.;  http://wso2.org
>  >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>  >> Blog: http://supunk.blogspot.com
>  >> ___
>  >> Carbon-dev mailing list
>  >> Carbon-dev@wso2.org
>  >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>  >
>  >
>  > ___
>  > Carbon-dev mailing list
>  > Carbon-dev@wso2.org
>  > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>  >
>  >
> 
> 
> 
>  --
>  Supun Kamburugamuva
>  Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>  Member, Apache Software Foundation; http://www.apache.org
>  WSO2 Inc.;  http://wso2.org
>  E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>  Blog: http://supunk.blogspot.com
>  ___
>  Carbon-dev mailing list
>  Carbon-dev@wso2.org
>  http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
> >>>
> >>>
> >>>
> >>> --
> >>>
> -
> >>> Waruna Ranasinghe
> >>> Senior Software Engineer, WSO2
> >>>
> >>> Mobile: +94 724 318285
> >>> BLOG: http://warunapw.blogspot.com
> >>>
> >>> www.wso2.com - "Lean . Enterprise . Middleware"
> >>>
> >>> ___
> >>> Carbon-dev mailing list
> >>> Carbon-dev@wso2.org
> >>> http://mail.wso2.org/cgi-bin/ma

Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Supun Kamburugamuva]

Having Caching for fail cases transparently from the user gives an in
consistency. Lets say a user accessed a resource before the registry
database failed. After the registry database has failed, user can
access this particular resource but he may not be able to access
another resource. From a programmers perspective this is not
consistent.

Thanks,
Supun..

On Fri, Apr 22, 2011 at 4:58 PM, Afkham Azeez  wrote:
>
>
> On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu  wrote:
>>
>>
>> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe 
>> wrote:
>>>
>>>
>>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva 
>>> wrote:

 For the users of the registry, it is important to know weather
 registry database is down.

 For example we have the requirement of caching the resources at
 theimplemtation
 ESB level and manage these caches according to the ESB specific
 configurations. So I believe we have implemented something that should
 have being implemented at the application layer at the registry level.

 The correct way to implement this kind of functionalities in the
 registry is using an adapter kind of approach. If a user wants
 registry resource caching they can use a adapter to access the
 registry instead of direct access.
>>>
>>> Or we may introduce a mechanism to disable registry caching. In the
>>> current implementation there is no way to disable registry caching.
>>
>> AFAIK Senaka did some changes recently and made registry caching
>> configurable. Also with the default configuration registry caching is
>> disabled.
>
> default should be caching enabled.
>
>>
>> Thanks,
>> Janaka
>>>
>>> Thanks,
>>> Waruna
>>>

 Thanks,
 Supun..

 On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe 
 wrote:
 > How else would you expect a cache to behave? ;-)
 > /sumedha
 >
 > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva 
 > wrote:
 >>
 >> I tried to shut down the registry database and access the registry
 >> resources. It seems, even though the database is down registry is
 >> serving the resources from a cache. Is this the behavior of the
 >> registry?
 >>
 >> Thanks,
 >> --
 >> Supun Kamburugamuva
 >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
 >> Member, Apache Software Foundation; http://www.apache.org
 >> WSO2 Inc.;  http://wso2.org
 >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
 >> Blog: http://supunk.blogspot.com
 >> ___
 >> Carbon-dev mailing list
 >> Carbon-dev@wso2.org
 >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
 >
 >
 > ___
 > Carbon-dev mailing list
 > Carbon-dev@wso2.org
 > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
 >
 >



 --
 Supun Kamburugamuva
 Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
 Member, Apache Software Foundation; http://www.apache.org
 WSO2 Inc.;  http://wso2.org
 E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
 Blog: http://supunk.blogspot.com
 ___
 Carbon-dev mailing list
 Carbon-dev@wso2.org
 http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>>
>>>
>>>
>>> --
>>> -
>>> Waruna Ranasinghe
>>> Senior Software Engineer, WSO2
>>>
>>> Mobile: +94 724 318285
>>> BLOG: http://warunapw.blogspot.com
>>>
>>> www.wso2.com - "Lean . Enterprise . Middleware"
>>>
>>> ___
>>> Carbon-dev mailing list
>>> Carbon-dev@wso2.org
>>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>>
>>
>>
>>
>> --
>> Janaka Ranabahu
>> Software Engineer
>> WSO2 Inc.
>> Mobile +94 718370861
>> Email : jan...@wso2.com
>> Blog : janakaranabahu.blogspot.com
>>
>> ___
>> Carbon-dev mailing list
>> Carbon-dev@wso2.org
>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>
>
>
>
> --
> Afkham Azeez
> Senior Software Architect & Senior Manager; WSO2, Inc.; http://wso2.com,
>
> Member; Apache Software Foundation; http://www.apache.org/
> email: az...@wso2.com cell: +94 77 3320919
> blog: http://blog.afkham.org
> twitter: http://twitter.com/afkham_azeez
> linked-in: http://lk.linkedin.com/in/afkhamazeez
>
> Lean . Enterprise . Middleware
>
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
>



-- 
Supun Kamburugamuva
Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
Member, Apache Software Foundation; http://www.apache.org
WSO2 Inc.;  http://wso2.org
E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
Blog: http://supunk.blogspot.com

Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Afkham Azeez]

On Fri, Apr 22, 2011 at 4:24 PM, Janaka Ranabahu  wrote:

>
>
> On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe wrote:
>
>>
>>
>> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva wrote:
>>
>>>  For the users of the registry, it is important to know weather
>>> registry database is down.
>>>
>>> For example we have the requirement of caching the resources at
>>> theimplemtation
>>>
>>> ESB level and manage these caches according to the ESB specific
>>> configurations. So I believe we have implemented something that should
>>> have being implemented at the application layer at the registry level.
>>>
>>> The correct way to implement this kind of functionalities in the
>>> registry is using an adapter kind of approach. If a user wants
>>> registry resource caching they can use a adapter to access the
>>> registry instead of direct access.
>>>
>>
>> Or we may introduce a mechanism to disable registry caching. In the
>> current implementation there is no way to disable registry caching.
>>
>
> AFAIK Senaka did some changes recently and made registry caching
> configurable. Also with the default configuration registry caching is
> disabled.
>

default should be caching enabled.


>
> Thanks,
> Janaka
>
>>
>> Thanks,
>> Waruna
>>
>>
>>>
>>> Thanks,
>>> Supun..
>>>
>>> On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe 
>>> wrote:
>>> > How else would you expect a cache to behave? ;-)
>>> > /sumedha
>>> >
>>> > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva 
>>> wrote:
>>> >>
>>> >> I tried to shut down the registry database and access the registry
>>> >> resources. It seems, even though the database is down registry is
>>> >> serving the resources from a cache. Is this the behavior of the
>>> >> registry?
>>> >>
>>> >> Thanks,
>>> >> --
>>> >> Supun Kamburugamuva
>>> >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>>> >> Member, Apache Software Foundation; http://www.apache.org
>>> >> WSO2 Inc.;  http://wso2.org
>>> >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>>> >> Blog: http://supunk.blogspot.com
>>> >> ___
>>> >> Carbon-dev mailing list
>>> >> Carbon-dev@wso2.org
>>> >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>> >
>>> >
>>> > ___
>>> > Carbon-dev mailing list
>>> > Carbon-dev@wso2.org
>>> > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>> >
>>> >
>>>
>>>
>>>
>>> --
>>> Supun Kamburugamuva
>>> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>>> Member, Apache Software Foundation; http://www.apache.org
>>> WSO2 Inc.;  http://wso2.org
>>> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>>> Blog: http://supunk.blogspot.com
>>> ___
>>> Carbon-dev mailing list
>>> Carbon-dev@wso2.org
>>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>>
>>
>>
>>
>> --
>> -
>> Waruna Ranasinghe
>> Senior Software Engineer, WSO2
>>
>> Mobile: +94 724 318285
>> BLOG: http://warunapw.blogspot.com
>>
>> www.wso2.com - "Lean . Enterprise . Middleware"
>>
>> ___
>> Carbon-dev mailing list
>> Carbon-dev@wso2.org
>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>
>>
>
>
> --
> Janaka Ranabahu
> Software Engineer
> WSO2 Inc.
>
> Mobile +94 718370861
> Email : jan...@wso2.com
> Blog : janakaranabahu.blogspot.com
>
>
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
>


-- 
*Afkham Azeez*
Senior Software Architect & Senior Manager; WSO2, Inc.; http://wso2.com,
*
*
*Member; Apache Software Foundation;
**http://www.apache.org/*
*
email: **az...@wso2.com* * cell: +94 77 3320919
blog: **http://blog.afkham.org* *
twitter: **http://twitter.com/afkham_azeez*
*
linked-in: **http://lk.linkedin.com/in/afkhamazeez*
*
*
*Lean . Enterprise . Middleware*
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Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Janaka Ranabahu]

On Fri, Apr 22, 2011 at 3:47 PM, Waruna Ranasinghe  wrote:

>
>
> On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva wrote:
>
>>  For the users of the registry, it is important to know weather
>> registry database is down.
>>
>> For example we have the requirement of caching the resources at
>> theimplemtation
>>
>> ESB level and manage these caches according to the ESB specific
>> configurations. So I believe we have implemented something that should
>> have being implemented at the application layer at the registry level.
>>
>> The correct way to implement this kind of functionalities in the
>> registry is using an adapter kind of approach. If a user wants
>> registry resource caching they can use a adapter to access the
>> registry instead of direct access.
>>
>
> Or we may introduce a mechanism to disable registry caching. In the current
> implementation there is no way to disable registry caching.
>

AFAIK Senaka did some changes recently and made registry caching
configurable. Also with the default configuration registry caching is
disabled.

Thanks,
Janaka

>
> Thanks,
> Waruna
>
>
>>
>> Thanks,
>> Supun..
>>
>> On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe 
>> wrote:
>> > How else would you expect a cache to behave? ;-)
>> > /sumedha
>> >
>> > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva 
>> wrote:
>> >>
>> >> I tried to shut down the registry database and access the registry
>> >> resources. It seems, even though the database is down registry is
>> >> serving the resources from a cache. Is this the behavior of the
>> >> registry?
>> >>
>> >> Thanks,
>> >> --
>> >> Supun Kamburugamuva
>> >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>> >> Member, Apache Software Foundation; http://www.apache.org
>> >> WSO2 Inc.;  http://wso2.org
>> >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>> >> Blog: http://supunk.blogspot.com
>> >> ___
>> >> Carbon-dev mailing list
>> >> Carbon-dev@wso2.org
>> >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>> >
>> >
>> > ___
>> > Carbon-dev mailing list
>> > Carbon-dev@wso2.org
>> > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>> >
>> >
>>
>>
>>
>> --
>> Supun Kamburugamuva
>> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>> Member, Apache Software Foundation; http://www.apache.org
>> WSO2 Inc.;  http://wso2.org
>> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>> Blog: http://supunk.blogspot.com
>> ___
>> Carbon-dev mailing list
>> Carbon-dev@wso2.org
>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>>
>
>
>
> --
> -
> Waruna Ranasinghe
> Senior Software Engineer, WSO2
>
> Mobile: +94 724 318285
> BLOG: http://warunapw.blogspot.com
>
> www.wso2.com - "Lean . Enterprise . Middleware"
>
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
>


-- 
Janaka Ranabahu
Software Engineer
WSO2 Inc.

Mobile +94 718370861
Email : jan...@wso2.com
Blog : janakaranabahu.blogspot.com
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Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Waruna Ranasinghe]

On Fri, Apr 22, 2011 at 3:39 PM, Supun Kamburugamuva  wrote:

> For the users of the registry, it is important to know weather
> registry database is down.
>
> For example we have the requirement of caching the resources at
> theimplemtation
> ESB level and manage these caches according to the ESB specific
> configurations. So I believe we have implemented something that should
> have being implemented at the application layer at the registry level.
>
> The correct way to implement this kind of functionalities in the
> registry is using an adapter kind of approach. If a user wants
> registry resource caching they can use a adapter to access the
> registry instead of direct access.
>

Or we may introduce a mechanism to disable registry caching. In the current
implementation there is no way to disable registry caching.

Thanks,
Waruna


>
> Thanks,
> Supun..
>
> On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe 
> wrote:
> > How else would you expect a cache to behave? ;-)
> > /sumedha
> >
> > On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva 
> wrote:
> >>
> >> I tried to shut down the registry database and access the registry
> >> resources. It seems, even though the database is down registry is
> >> serving the resources from a cache. Is this the behavior of the
> >> registry?
> >>
> >> Thanks,
> >> --
> >> Supun Kamburugamuva
> >> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
> >> Member, Apache Software Foundation; http://www.apache.org
> >> WSO2 Inc.;  http://wso2.org
> >> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
> >> Blog: http://supunk.blogspot.com
> >> ___
> >> Carbon-dev mailing list
> >> Carbon-dev@wso2.org
> >> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
> >
> >
> > ___
> > Carbon-dev mailing list
> > Carbon-dev@wso2.org
> > http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
> >
> >
>
>
>
> --
> Supun Kamburugamuva
> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
> Member, Apache Software Foundation; http://www.apache.org
> WSO2 Inc.;  http://wso2.org
> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
> Blog: http://supunk.blogspot.com
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>



-- 
-
Waruna Ranasinghe
Senior Software Engineer, WSO2

Mobile: +94 724 318285
BLOG: http://warunapw.blogspot.com

www.wso2.com - "Lean . Enterprise . Middleware"
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Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Supun Kamburugamuva]

For the users of the registry, it is important to know weather
registry database is down.

For example we have the requirement of caching the resources at the
ESB level and manage these caches according to the ESB specific
configurations. So I believe we have implemented something that should
have being implemented at the application layer at the registry level.

The correct way to implement this kind of functionalities in the
registry is using an adapter kind of approach. If a user wants
registry resource caching they can use a adapter to access the
registry instead of direct access.

Thanks,
Supun..

On Fri, Apr 22, 2011 at 3:29 PM, Sumedha Rubasinghe  wrote:
> How else would you expect a cache to behave? ;-)
> /sumedha
>
> On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva  wrote:
>>
>> I tried to shut down the registry database and access the registry
>> resources. It seems, even though the database is down registry is
>> serving the resources from a cache. Is this the behavior of the
>> registry?
>>
>> Thanks,
>> --
>> Supun Kamburugamuva
>> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
>> Member, Apache Software Foundation; http://www.apache.org
>> WSO2 Inc.;  http://wso2.org
>> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
>> Blog: http://supunk.blogspot.com
>> ___
>> Carbon-dev mailing list
>> Carbon-dev@wso2.org
>> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
>
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
>



-- 
Supun Kamburugamuva
Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
Member, Apache Software Foundation; http://www.apache.org
WSO2 Inc.;  http://wso2.org
E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
Blog: http://supunk.blogspot.com
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Re: [Carbon-dev] Does registry serves cached values even after the DB goes down?

[Sumedha Rubasinghe]

How else would you expect a cache to behave? ;-)

/sumedha

On Fri, Apr 22, 2011 at 3:27 PM, Supun Kamburugamuva  wrote:

> I tried to shut down the registry database and access the registry
> resources. It seems, even though the database is down registry is
> serving the resources from a cache. Is this the behavior of the
> registry?
>
> Thanks,
> --
> Supun Kamburugamuva
> Technical Lead &  Product Manager, WSO2 Inc.; http://wso2.com
> Member, Apache Software Foundation; http://www.apache.org
> WSO2 Inc.;  http://wso2.org
> E-mail: su...@wso2.com;  Mobile: +94 77 431 3585
> Blog: http://supunk.blogspot.com
> ___
> Carbon-dev mailing list
> Carbon-dev@wso2.org
> http://mail.wso2.org/cgi-bin/mailman/listinfo/carbon-dev
>
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